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Improved pharmacokinetic profile of levornidazole following intravenous infusion of 750 mg every 24 h compared with 500 mg every 12 h in healthy Chinese volunteers
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International Journal of Antimicrobial Agents xxx (2016) xxx–xxx
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International Journal of Antimicrobial Agents journal homepage: http://www.elsevier.com/locate/ijantimicag
Short Communication
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Improved pharmacokinetic profile of levornidazole following intravenous infusion of 750 mg every 24 h compared with 500 mg every 12 h in healthy Chinese volunteers
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Yuran Cao a,b,1 , Xiaojie Wu a,b,1 , Yuancheng Chen a,b , Beining Guo a,b , Jicheng Yu a,b , Guoying Cao a,b , Jing Zhang a,b,∗ , Yaoguo Shi a,b , Yingyuan Zhang a,b a
Institute of Antibiotics, Huashan Hospital, Fudan University, 12 Middle Wulumuqi Road, Shanghai 200040, China Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, 12 Middle Wulumuqi Road, Shanghai 200040, China
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Article history: Received 16 October 2015 Accepted 9 December 2015
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Keywords: Levornidazole Pharmacokinetics Safety Metabolite Dosage regimen
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1. Introduction
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Levornidazole is the levo-isomer of ornidazole with similar anti-anaerobic activity and lower central neurotoxicity compared with ornidazole. This open-label, parallel, randomised, multidose trial was conducted to compare the pharmacokinetics and safety of levornidazole following intravenous (i.v.) infusion 750 mg every 24 h (q24h) (test group, 12 subjects) versus 500 mg every 12 h (q12h) (reference group, 12 subjects) for 7 days in healthy Chinese volunteers. Following i.v. infusion for 7 days, the test group showed a 33.8% lower accumulation ratio (AR) and a 45.0% higher volume of distribution of levornidazole than the reference group. The cumulative urinary excretion rate of levornidazole during the 0–72 h period (Ae0–72 ) was 16.6 ± 20.9% in the test group and 24.2 ± 5.7% in the reference group. The metabolite M1/parent and M4/parent ratios were, respectively, 2.18 ± 0.77% and 2.94 ± 0.37% in test group and 3.15 ± 1.09% and 3.18 ± 0.34% in the reference group. The Ae0–72 of M1, M2 and M4 were all <10% in both groups. Both regimens were well tolerated. Drug-related adverse events were generally transient and were mild or moderate in severity. These findings support the recommendation of i.v. infusion of levornidazole 750 mg q24h in clinical practice, which shows a lower AR and similar safety compared with the conventional 500 mg q12h regimen. [Chinese Clinical Trial Registry identifier: ChiCTR-IPR-14005574.] © 2016 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
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Ornidazole [1-(3-chloro-2-hydroxypropyl)-2-methyl-5nitroimidazole] is used for the treatment of infections caused by anaerobic and microaerophilic bacteria and protozoa [1]. Levornidazole, the levo-isomer of ornidazole, is a new 5nitroimidazole antimicrobial agent showing good anti-anaerobic activity and antiprotozoal activity [2]. Levornidazole has shown significantly lower central neurotoxicity [3] and no chiral inversion and self-inhibitory effect in vivo [4,5]. In vitro pharmacodynamic studies have demonstrated that levornidazole has a comparable antimicrobial spectrum and more potent antimicrobial activity compared with ornidazole [6]. Clinical trials have shown the good
∗ Corresponding author. Present address: Institute of Antibiotics, Huashan Hospital, 12 Middle Wulumuqi Road, Shanghai 200040, China. Tel.: +86 21 5288 8190; fax: +86 21 6248 4347. E-mail address: zhangj [email protected] (J. Zhang). 1 These authors contributed equally to this work.
efficacy and safety profile of levornidazole 500 mg twice daily via intravenous (i.v.) infusion for 5 days to treat pelvic and oral anaerobic infections [7,8]. Results of a phase 1 clinical trial [9] showed that levornidazole was well tolerated in healthy Chinese volunteers. No serious adverse events (AEs) occurred up to the maximum levornidazole dose of 1500 mg. A linear dose–response relationship with maximum plasma concentration (Cmax ) and area under concentration–time curve (AUC) was demonstrated in volunteers treated with 500 mg to 1500 mg levornidazole. According to the insert package, the AUC, renal clearance and volume of distribution following i.v. infusion of levornidazole 500 mg twice daily for 5 days are significantly different from the corresponding values following a single dose, suggesting accumulation of levornidazole to some extent in vivo. According to these reported pharmacokinetic parameters, it is predicted that i.v. infusion of 750 mg every 24 h (q24h) may reduce the levornidazole accumulation ratio (AR) to 1.3 from 1.93 for the conventional regimen of 500 mg every 12 h (q12h). However, this is only a preliminary prediction requiring clinical validation.
http://dx.doi.org/10.1016/j.ijantimicag.2015.12.007 0924-8579/© 2016 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
Please cite this article in press as: Cao Y, et al. Improved pharmacokinetic profile of levornidazole following intravenous infusion of 750 mg every 24 h compared with 500 mg every 12 h in healthy Chinese volunteers. Int J Antimicrob Agents (2016), http://dx.doi.org/10.1016/j.ijantimicag.2015.12.007
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The metabolite of ornidazole in humans is poorly understood, although ornidazole has been used for a long time in clinical practice. It has been reported that ornidazole is metabolised to five phase 1 metabolites in human urine: M1, 1-chloro-3-(2hydroxymethyl-5-nitro-1-imidazolyl)-2-propanol; M2, 2-methyl5-nitroimidazole; M3, N-(3-chloro-2-hydroxypropyl)acetamide; M4, 3-(2-methyl-5-nitro-1-imidazolyl)-1, 2-propanediol; and M5, acetamide [10]. The pharmacodynamic results of levornidazole and its phase 1 metabolites indicated that M1 and M4 had similar antianaerobic activity to levornidazole in vitro [11]. Therefore, it is necessary to study the pharmacokinetics of these metabolites to examine whether they will influence the efficacy of levornidazole in vivo. The primary objective of this open-label, parallel, randomised, multidose trial was to investigate the pharmacokinetics and safety profile of levornidazole following two dosage regimens (750 mg q24h versus 500 mg q12h) in healthy Chinese volunteers. The secondary objective was to investigate the pharmacokinetics of levornidazole metabolites.
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2. Materials and methods
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2.1. Study design
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This was an open-label, parallel, randomised, multidose trial conducted at a single centre in China (Phase I Clinical Research Center at Huashan Hospital, Fudan University, Shanghai, China). The study cohort comprised 24 healthy Chinese subjects who were randomised to receive levornidazole sodium chloride injection 750 mg q24h (test group) or 500 mg q12h (reference regimen) via i.v. infusion. There were 12 subjects (6 males and 6 females) in each group. The study protocol and informed consent were approved by the Ethics Committee of Huashan Hospital, Fudan University, and the study was conducted according to the protocol, the Declaration of Helsinki, Good Clinical Practice and applicable local regulations. All subjects gave their written informed consent before study.
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2.2. Study subjects
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Healthy male or female Chinese adults aged 19–45 years with a body mass index (BMI) between 19 kg/m2 and 24 kg/m2 were included if their medical history, physical examination, electrocardiogram and clinical laboratory tests at screening did not reveal any abnormalities. Eligible subjects had a negative urine screen for alcohol or controlled drugs and were using an appropriate barrier method of birth control. Subjects were excluded if they had any of the following: a history of significant cardiovascular, hepatic, renal, haematological, neurological or psychiatric disorder; positive for antibody to human immunodeficiency virus (HIV), hepatitis B surface antigen, or antibody to hepatitis C virus; not satisfying the inclusion criteria for systolic blood pressure (≥90 mmHg and ≤140 mmHg), diastolic blood pressure (≥40 mmHg and ≤90 mmHg), pulse rate (≥40 per min and ≤99 per min) or QTc (≤450 ms); a history of drug allergy or drug abuse; donated blood or plasma >400 mL within 90 days of study initiation; participated in another clinical trial within 60 days prior to study entry; or received any prescription or overthe-counter medication within 14 days prior to study initiation. Subjects who could not tolerate levornidazole were also excluded.
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2.3. Drug administration
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subjects received a single dose of 750 mg (test group) or 500 mg (reference group) levornidazole at 07:00 h on Day 1 (first dose) and Day 11 (last dose). From Days 4 to 10, subjects in the test group were given 750 mg levornidazole once daily (07:00 h), whilst subjects in the reference group received 500 mg levornidazole twice daily (07:00 h and 19:00 h). The i.v. infusion of levornidazole was completed over 90 ± 10 min in the test group and over 60 ± 10 min in the reference group. 2.4. Blood and urine sample collection For the first and last doses of levornidazole, blood samples were drawn immediately before (0) and 0.33 h after the start of infusion, and immediately and 0.5, 1, 2, 4, 8, 12, 24, 36, 48, 60 and 72 h after the end of i.v. infusion. From Days 4 to 10, blood samples were drawn immediately before the start of the first infusion on Days 4, 8, 9 and 10, and immediately and 2, 6 and 12 h after the end of the first infusion on Day 8. Approximately 4 mL of blood was drawn each time. Plasma was separated and stored in polypropylene tubes at −40 ± 5 ◦ C until analysis. Urine samples were collected at the following time periods: −12 h to 0 h before administration of the first and last doses, and 0–4 h, 4–8 h, 8–12 h, 12–24 h, 24–48 h and 48–72 h after i.v. infusion of the first and last doses. After measurement of urine volume, a 4 mL urine sample was immediately stored in polypropylene tubes at −40 ± 5 ◦ C until analysis. 2.5. Laboratory assay The concentrations of levornidazole and its metabolites M1, M2 and M4 in plasma and urine were measured using a fully validated ultra-performance liquid chromatographic–tandem mass spectrometric (UPLC–MS/MS) method as described previously [12] and designed with reference to the US Food and Drug Administration (FDA) guidance for industry [13]. Levornidazole, M1, M2 and M4 were detectable with this method in the range of 0.0100–5.00, 0.00500–2.50, 0.0200–10.0 and 0.00250–1.25 g/mL. The lower limit of quantification (LLOQ) was 0.0100, 0.00500, 0.0200 and 0.00250 g/mL for levornidazole, M1, M2 and M4, respectively, both in plasma and urine. 2.6. Calculation of pharmacokinetic parameters The area under the plasma drug concentration–time curve during 0–24 h (AUC0–24 ) was calculated as AUC0–25.5 in the test group and 2 × AUC0–13 in the reference group. Maximum plasma concentration (Cmax ), terminal elimination half-life (t1/2 ), apparent volume of distribution (Vd ) and creatinine clearance (CLCr ) after the administration on Day 1 as well as the steadystate parameters Cmax ss , AUC0–24 ss , Vd ss and CLCr ss on Day 7 were estimated by non-compartmental analysis based on plasma concentrations of levornidazole, M1, M2 and M4 using Phoenix WinNonlin 6.0 software (Pharsight, Princeton, NJ). The accumulation ratio (AR = AUC0–24, Day 7 /AUC0–24, Day 1 ) of levornidazole, and the metabolite/parent ratio (MR = AUC0–24 metabolite / AUC0–24, parent drug × 100%) of metabolites were also calculated. The cumulative urinary excretion amount during 0–72 h, the cumulative urinary excretion rate and renal clearance rate were calculated. Compartmental analysis was also carried out using Phoenix WinNonlin 6.0 software to characterise the pharmacokinetics of levornidazole. 2.7. Safety evaluation
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Levornidazole 500 mg (volume 100 mL; lot 201210151, Sanhome Pharmaceutical Co. Ltd., Nanjing, China) was prepared in 100 mL of 0.9% sodium chloride for injection just prior to administration. Levornidazole was administered on the following schedule:
All subjects were included in the safety evaluation. The safety and tolerability profile of the two dosage regimens of levornidazole were assessed with the data for AEs, clinical laboratory tests,
Please cite this article in press as: Cao Y, et al. Improved pharmacokinetic profile of levornidazole following intravenous infusion of 750 mg every 24 h compared with 500 mg every 12 h in healthy Chinese volunteers. Int J Antimicrob Agents (2016), http://dx.doi.org/10.1016/j.ijantimicag.2015.12.007
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Table 1 Non-compartmental pharmacokinetic parameters of levornidazole and its metabolites following intravenous infusion of levornidazole 750 mg q24h versus 500 mg q12h in healthy Chinese volunteers.
Levornidazole
M1
M4
Dosage regimena
Parameter
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
t1/2 (h)
CLCr (L/h)
Cmax (g/mL)
AUC0–24 (h g/mL)
MR (%)
Day 1
Day 1
Day 7
Day 1
Day 7
Day 1
Day 7
Day 1
Day 1
Day 7
11.6 0.8 11.9 1.3 −0.474 0.640
2.96 0.56 2.90 0.51 0.275 0.786
2.70 0.63 2.60 0.43 0.441 0.664
49.3 9.1 50.0 8.6 0.096 0.924
22.9 4.8 33.2 4.8 −5.14 0.000
12.5 3.4 17.3 2.2 −4.10 0.000
22.3 5.3 22.1 3.2 0.082 0.936
88.7 196 16.8 52 201 295 32 45 −10.9 −4.86 0.000 0.000
N/A
N/A
N/A
N/A
N/A
N/A
11.8 1.5 12.5 2.4 −0.310 0.759
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
0.477 0.255 0.296 0.140 2.13 0.048
1.14 0.41 2.86 1.14 −4.94 0.000
5.62 3.07 6.21 3.00 −0.463 0.648
2.06 0.55 1.63 0.45 2.06 0.052
3.15 1.09 2.18 0.77 2.43 0.024
N/A
N/A
0.118 0.043 0.150 0.060 −1.50 0.147
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
0.432 0.099 0.348 0.055 2.49 0.021
1.44 0.34 3.86 0.58 −12.5 0.000
4.86 1.16 7.38 1.24 −5.05 0.000
2.58 0.13 2.47 0.39 0.896 0.386
3.18 0.34 2.94 0.37 1.65 0.114
N/A
N/A
0.131 0.027 0.184 0.030 −4.56 0.000
12.1 1.2 14.2 3.1 −2.22 0.037
Vd (L)
Day 7
AR
2.19 0.30 1.45 0.16 7.33 0.000
N/A N/A
N/A N/A
q24h, every 24 h; q12h, every 12 h; t1/2 , terminal elimination half-life; CLCr , creatinine clearance; Vd , apparent volume of distribution; Cmax , maximum plasma concentration; AUC0–24 , area under the plasma concentration–time curve during 0–24 h (500 mg q12h: 2 × AUC0–13 ; 750 mg q24h: AUC0–25.5 ); MR, metabolite/parent ratio (=AUC0–24, metabolite /AUC0–24, parent drug × 100%); AR, accumulation ratio (=AUC0–24, Day 7 /AUC0–24, Day 1 ); S.D., standard deviation; N/A, not available. a 500 mg q12h dosage regimen: n = 12; 750 mg q24h dosage regimen: n = 12 on Day 1, n = 11 on Day 7 (1 subject was withdrawn from the study 24 h after the first dose). b Independent sample t-test.
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vital signs, electrocardiogram and physical examination. Laboratory tests were conducted on the screening day, Day −1, Days 1, 4 and 8 before infusion of the first dose, and Day 14 before leaving the ward. 2.8. Statistical analysis The pharmacokinetic parameters and urinary excretion parameters were summarised using descriptive statistics. The independent sample t-test was used to evaluate the difference between test group and reference group. P < 0.05 was considered statistically significant.
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3. Results
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3.1. Patient characteristics
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A total of 24 healthy Chinese subjects were enrolled. Subjects in the test group and the reference group had a mean ± standard deviation age of 24.25 ± 2.53 years and 23.75 ± 1.71 years, respectively, and mean BMI of 22.03 ± 1.63 kg/m2 and 21.86 ± 1.53 kg/m2 , respectively. The demographic characteristics were balanced between groups. All subjects completed the trial, except for one subject in test group who was withdrawn on Day 2 owing to apical periodontal abscess and increased neutrophils.
3.2. Pharmacokinetic parameters
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The plasma concentration–time curves of levornidazole are presented in Supplementary Fig. S1. The profile of levornidazole, M1 and M4 was similar in both groups. The plasma concentration of M2 was almost lower than the LLOQ (0.0200 g/mL) in both groups. The results of non-compartmental pharmacokinetic analysis based on the plasma concentrations of levornidazole, M1 and M4 are presented in Table 1. The t1/2 , CLCr and Vd of levornidazole on Day 1 were similar between the two dose groups, whilst Cmax and AUC0–24 were significantly higher in the test group (P < 0.05). The Cmax ss on Day 7 did not show a significant difference between the two groups, although AUC0–24 ss in the test group was 50.5% higher than that in reference group. The AR of levornidazole was 1.45 ± 0.16 in the test group, which is 33.8% lower than that in the reference group (2.19 ± 0.30). The Vd ss of levornidazole in the test group was 45.0% higher than that in reference group. The MR of M1 and M4 was, respectively, 2.18 ± 0.77% and 2.94 ± 0.37% in the test group and 3.15 ± 1.09% and 3.18 ± 0.34% in the reference group. Compartmental analysis demonstrated that a two-compartment model (r = 1/C) was well fitted with the observed concentrations of levornidazole (see Table 2 and Supplementary Fig. S2). Urinary excretion parameters of levornidazole, M1, M2 and M4 are presented in Table 3. The urinary excretion parameters
Table 2 Two-compartmental pharmacokinetic parameters of levornidazole following intravenous infusion of 750 mg q24h versus 500 mg q12h in healthy Chinese volunteers. Dosage regimena
Parameter
V1 (L)
V2 (L)
k10 (1/h)
k12 (1/h)
k21 (1/h)
t1/2 ␣ (h)
t1/2  (h)
CL (L/h)
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
29.47 11.10 28.34 12.50 0.234 0.419
20.12 10.57 21.17 16.15 −0.187 0.066
0.110 0.036 0.120 0.053 −0.496 0.133
5.10 3.46 4.77 3.38 0.243 0.859
6.45 1.91 6.58 2.87 −0.122 0.018
0.074 0.054 0.062 0.010 0.725 0.090
12.04 1.29 12.30 1.67 −0.421 0.473
2.92 0.64 2.85 0.57 0.273 0.490
q24h, every 24 h; q12h, every 12 h; V1 , volume of distribution of central compartment; V2 , volume of distribution of peripheral compartment; k10 , elimination rate constant leaving central compartment; k12 , transfer rate constant from central compartment to peripheral compartment; k21 , transfer rate constant from peripheral compartment to central compartment; t1/2 ␣ , distribution phase half-life; t1/2  , elimination phase half-life; CL, clearance from central compartment; S.D., standard deviation. a 500 mg q12h: n = 12; 750 mg q24h: n = 12 on Day 1, n = 11 on Day 7 (1 subject was withdrawn 24 h after the first dose). b Independent sample t-test.
Please cite this article in press as: Cao Y, et al. Improved pharmacokinetic profile of levornidazole following intravenous infusion of 750 mg every 24 h compared with 500 mg every 12 h in healthy Chinese volunteers. Int J Antimicrob Agents (2016), http://dx.doi.org/10.1016/j.ijantimicag.2015.12.007
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Table 3 Urinary excretion parameters of levornidazole and its metabolites M1, M2 and M4 following intravenous infusion of levornidazole 750 mg q24h or 500 mg q12h for 7 days in healthy Chinese volunteers. Dosage regimena
Parameter
Day 1 Ratemax (mg/h)
Day 7 Ae0–72 (%)
CLr (L/h)
Ratemax (mg/h)
Ae0–72 (%)
CLr (L/h)
0.283 0.075 0.269 0.097 0.396 0.696
10.5 3.0 13.3 24.3 −0.393 0.699
24.2 5.7 16.6 20.9 1.20 0.242
0.335 0.083 0.306 0.313 0.310 0.761
1.08 0.41 1.37 2.82 −0.345 0.733
3.67 1.44 2.71 3.95 0.789 0.439
N/A
0.07 0.03 0.03 0.02 3.51 0.002
N/A
7.30 0.94 4.51 5.69 1.67 0.109
N/A
Levornidazole
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
3.29 1.41 5.11 2.31 −2.33 0.031
9.56 2.15 9.32 3.51 0.206 0.839
M1
500 mg q12h
Mean S.D. Mean S.D.
0.213 0.059 0.342 0.148 −2.80 0.014
1.05 0.28 1.03 0.50 −0.140 0.887
N/A
0.00 0.00 0.01 0.01 1.19 0.247
N/A
N/A
N/A
N/A
N/A
N/A
2.62 0.27 1.97 0.99 2.20 0.039
N/A
2.01 0.25 2.09 3.8 −0.068 0.946
750 mg q24h tb P-value M2
M4
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
N/A N/A N/A 0.471 0.027 0.571 0.305 −1.13 0.271
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
q24h, every 24 h; q12h, every 12 h; Ratemax , maximum excretion rate in urine; Ae0–72 , cumulative urinary excretion rate during 0–72 h period; CLr , renal clearance; S.D., standard deviation; N/A, not available. a 500 mg q12h: n = 12; 750 mg q24h: n = 12 on Day 1, n = 11 on Day 7 (1 subject was withdrawn 24 h after the first dose). b Independent sample t-test.
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of levornidazole, M1 and M4 did not show a significant difference between the two groups.
3.3. Safety profile Following i.v. infusion of multiple doses of levornidazole, AEs were observed in 8 (33.3%) of the 24 subjects. All of the study drugrelated AEs were laboratory abnormalities (Supplementary Table S1), including three AEs in the test group and five AEs in the reference group (P > 0.05). These events were mild or moderate and resolved by the end of the study. No serious AEs were observed during the study. One subject in the test group was withdrawn on Day 2 owing to apical periodontal abscess and increased neutrophils. This subject was treated with concomitant medications. The investigator considered that this event was unrelated to the study medication.
4. Discussion The observed pharmacokinetic parameters following i.v. infusion of 500 mg levornidazole q12h in this study are consistent with previous studies [6]. Following i.v. infusion of multiple doses of levornidazole, the non-compartmental pharmacokinetic parameters AUC0–∞ and Cmax ss were comparable between the 750 mg q24h dose group and the 500 mg q12h dose group. However, the Vd ss of levornidazole was 45.0% higher and the AR was 33.8% lower than the values in the 500 mg q12h dose group. These data confirm that 750 mg q24h of levornidazole results in lower accumulation of levornidazole in vivo compared with the conventional 500 mg q12h regimen. This finding is supported by the plasma concentration–time curves in Supplementary Fig. S1.
Safety evaluation indicated that the incidence of abnormal liver function test AEs in the 750 mg q24h group was similar to those in the 500 mg q12h group. No serious AEs occurred in any group. The plasma concentration–time curves of M1 and M4 were similar to levornidazole. The MR of M1, M2 and M4 were all <5%. Pharmacodynamic studies of levornidazole and its phase 1 metabolites have shown that M1 and M4 have in vitro anti-anaerobic activity similar to levornidazole [11]. However, the metabolites may not influence the anti-anaerobic activity of levornidazole due to low MR in vivo. Only 24 healthy subjects were enrolled in this study. The sample size is limited. These preliminary results and conclusion should be further confirmed in a larger cohort of patients with pelvic anaerobic infections or other target patients. It is reported that levornidazole shows a concentrationdependent antibacterial property against Bacteroides fragilis in vitro using time–kill assay and sigmoid Emax model analysis [14]. We will design a further study to examine the pharmacokinetic/pharmacodynamic target values of levornidazole for treatment of B. fragilis infections. In conclusion, i.v. infusion of multiple doses of levornidazole 750 mg q24h has the advantages of a lower AR in vivo and a good safety profile compared with the conventional 500 mg q12h regimen. Therefore, a levornidazole 750 mg q24h dosage regimen can also be recommended for clinical treatment. Acknowledgments The authors would like to thank Nanjing Sanhome Pharmaceutical Co., Ltd. for their help in this study.
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Funding: This work was supported by the New Drug Creation and Q4 Manufacturing Program of the Ministry of Science and Technology of China [2012ZX09104101; 2012ZX09303004-001].
Please cite this article in press as: Cao Y, et al. Improved pharmacokinetic profile of levornidazole following intravenous infusion of 750 mg every 24 h compared with 500 mg every 12 h in healthy Chinese volunteers. Int J Antimicrob Agents (2016), http://dx.doi.org/10.1016/j.ijantimicag.2015.12.007
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Competing interests: Nanjing Sanhome Pharmaceutical Co., Ltd. provided the study drug levornidazole used in this study.
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Ethical approval: This study was approved by the Ethics Committee of Huashan Hospital, Fudan University (Shanghai, China) [approval no. 2012-222].
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Appendix A. Supplementary data
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Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.ijantimicag.2015. 12.007.
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References
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[1] López Nigro MM, Palermo AM, Mudry MD, Carballo MA. Cytogenetic evaluation of two nitroimidazole derivatives. Toxicol. In Vitro 2003;17:35–40. [2] Li HM, Mei YN, Xu D. In vitro antibacterial activity of ornidazole against 111 clinical isolates of anaerobes. Acta Univ. Med. Nanjing 2008;28:1500–2 (in Chinese). [3] Sun JH, Wang ZQ, Gu XL, Mu R. Comparative study of ornidazole enantiomers on the toxic and side effects to central nervous system in mice. J. China Pharm. Univ 2008;39:343–7 (in Chinese). [4] Mu LL, Cheng ZN, Guo X, Luo X, Yu P. Investigation of chiral inversion and pharmacokinetics of laevo-ornidazole by high-performance liquid chromatography. J. Clin. Pharm. Ther 2013;38:31–5.
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[5] Chen Y, Liu XQ, Zhong J, Zhao X, Wang Y, Wang G. Stereoselective pharmacokinetics of ornidazole after intravenous administration of individual enantiomers and the racemate. Chirality 2006;18:799–802. [6] Wang H, Hao K, Wang GJ. Determination of the resistant mutant-preventing concentrations of four antimicrobial agents including levornidazole and justification of clinical dosage. Prog. Pharmaceut. Sci 2012;6:277–81. [7] Ma L, Zhang YZ, Zheng YL, Wang ZH, Xu YD, Kong LN. Multicenter randomized controlled clinical study on levornidazole and sodium chloride injection in the treatment of pelvic anaerobic infections. Zhonghua Fu Chan Ke Za Zhi 2010;45:754–6 (in Chinese). [8] Chen S, Zhang HD, Wang YC, Lou DH, Tao XX. Efficacy of levornidazole sodium chloride injection in treating oral anaerobic infections. Jiangsu Med. J 2011;37:714–5 (in Chinese). [9] Zhao YN, Wu P, Sun H. Human tolerability and pharmacokinetic studies of levornidazole by dose escalation. Chin. Pharm. J 2011;46:454–7 (in Chinese). [10] Schwartz DE, Jordan JC, Vetter W, Oesterhelt G. Metabolic studies of ornidazole in the rat, in the dog and in man. Xenobiotica 1979;9:571–81. [11] Hu J, Zhang J, Wu S, Zhu D, Huang H, Chen Y, et al. Evaluation of the in vitro activity of levornidazole, its metabolites and comparators against clinical anaerobic bacteria. Int. J. Antimicrob. Agents 2014;44:514–9. [12] Cao Y, Zhao M, Wu X, Guo B, Chen Y, Yu J, et al. Quantification of levornidazole and its metabolites in human plasma and urine by ultra-performance liquid chromatography–mass spectrometry. J. Chromatogr. B: Analyt. Technol. Biomed. Life Sci 2014;963:119–27. [13] US Food and Drug Administration. Guidance for Industry, Bioanalytical Method Validation. Rockville, MD: US Department of Health and Human Services, Food and Drug Administration; 2001. http://www.fda.gov/downloads/Drugs/ GuidanceComplianceRegulatoryInformation/Guidances/ucm070107.pdf [accessed July 2012]. [14] Hu JL, Zhang J, Chen YC, Wu S, Zhu DM, Yang Y, Zhang YY. In vitro bactericidal property of levornidazole against Bacteroides fragilis studied by time-kill assay and sigmoid Emax model analysis. Int. J. Antimicrob. Agents 2015;45:673–5.
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International Journal of Antimicrobial Agents journal homepage: http://www.elsevier.com/locate/ijantimicag
Short Communication
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Improved pharmacokinetic profile of levornidazole following intravenous infusion of 750 mg every 24 h compared with 500 mg every 12 h in healthy Chinese volunteers
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Yuran Cao a,b,1 , Xiaojie Wu a,b,1 , Yuancheng Chen a,b , Beining Guo a,b , Jicheng Yu a,b , Guoying Cao a,b , Jing Zhang a,b,∗ , Yaoguo Shi a,b , Yingyuan Zhang a,b a
Institute of Antibiotics, Huashan Hospital, Fudan University, 12 Middle Wulumuqi Road, Shanghai 200040, China Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, 12 Middle Wulumuqi Road, Shanghai 200040, China
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Article history: Received 16 October 2015 Accepted 9 December 2015
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Keywords: Levornidazole Pharmacokinetics Safety Metabolite Dosage regimen
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1. Introduction
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Levornidazole is the levo-isomer of ornidazole with similar anti-anaerobic activity and lower central neurotoxicity compared with ornidazole. This open-label, parallel, randomised, multidose trial was conducted to compare the pharmacokinetics and safety of levornidazole following intravenous (i.v.) infusion 750 mg every 24 h (q24h) (test group, 12 subjects) versus 500 mg every 12 h (q12h) (reference group, 12 subjects) for 7 days in healthy Chinese volunteers. Following i.v. infusion for 7 days, the test group showed a 33.8% lower accumulation ratio (AR) and a 45.0% higher volume of distribution of levornidazole than the reference group. The cumulative urinary excretion rate of levornidazole during the 0–72 h period (Ae0–72 ) was 16.6 ± 20.9% in the test group and 24.2 ± 5.7% in the reference group. The metabolite M1/parent and M4/parent ratios were, respectively, 2.18 ± 0.77% and 2.94 ± 0.37% in test group and 3.15 ± 1.09% and 3.18 ± 0.34% in the reference group. The Ae0–72 of M1, M2 and M4 were all <10% in both groups. Both regimens were well tolerated. Drug-related adverse events were generally transient and were mild or moderate in severity. These findings support the recommendation of i.v. infusion of levornidazole 750 mg q24h in clinical practice, which shows a lower AR and similar safety compared with the conventional 500 mg q12h regimen. [Chinese Clinical Trial Registry identifier: ChiCTR-IPR-14005574.] © 2016 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
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Ornidazole [1-(3-chloro-2-hydroxypropyl)-2-methyl-5nitroimidazole] is used for the treatment of infections caused by anaerobic and microaerophilic bacteria and protozoa [1]. Levornidazole, the levo-isomer of ornidazole, is a new 5nitroimidazole antimicrobial agent showing good anti-anaerobic activity and antiprotozoal activity [2]. Levornidazole has shown significantly lower central neurotoxicity [3] and no chiral inversion and self-inhibitory effect in vivo [4,5]. In vitro pharmacodynamic studies have demonstrated that levornidazole has a comparable antimicrobial spectrum and more potent antimicrobial activity compared with ornidazole [6]. Clinical trials have shown the good
∗ Corresponding author. Present address: Institute of Antibiotics, Huashan Hospital, 12 Middle Wulumuqi Road, Shanghai 200040, China. Tel.: +86 21 5288 8190; fax: +86 21 6248 4347. E-mail address: zhangj [email protected] (J. Zhang). 1 These authors contributed equally to this work.
efficacy and safety profile of levornidazole 500 mg twice daily via intravenous (i.v.) infusion for 5 days to treat pelvic and oral anaerobic infections [7,8]. Results of a phase 1 clinical trial [9] showed that levornidazole was well tolerated in healthy Chinese volunteers. No serious adverse events (AEs) occurred up to the maximum levornidazole dose of 1500 mg. A linear dose–response relationship with maximum plasma concentration (Cmax ) and area under concentration–time curve (AUC) was demonstrated in volunteers treated with 500 mg to 1500 mg levornidazole. According to the insert package, the AUC, renal clearance and volume of distribution following i.v. infusion of levornidazole 500 mg twice daily for 5 days are significantly different from the corresponding values following a single dose, suggesting accumulation of levornidazole to some extent in vivo. According to these reported pharmacokinetic parameters, it is predicted that i.v. infusion of 750 mg every 24 h (q24h) may reduce the levornidazole accumulation ratio (AR) to 1.3 from 1.93 for the conventional regimen of 500 mg every 12 h (q12h). However, this is only a preliminary prediction requiring clinical validation.
http://dx.doi.org/10.1016/j.ijantimicag.2015.12.007 0924-8579/© 2016 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
Please cite this article in press as: Cao Y, et al. Improved pharmacokinetic profile of levornidazole following intravenous infusion of 750 mg every 24 h compared with 500 mg every 12 h in healthy Chinese volunteers. Int J Antimicrob Agents (2016), http://dx.doi.org/10.1016/j.ijantimicag.2015.12.007
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The metabolite of ornidazole in humans is poorly understood, although ornidazole has been used for a long time in clinical practice. It has been reported that ornidazole is metabolised to five phase 1 metabolites in human urine: M1, 1-chloro-3-(2hydroxymethyl-5-nitro-1-imidazolyl)-2-propanol; M2, 2-methyl5-nitroimidazole; M3, N-(3-chloro-2-hydroxypropyl)acetamide; M4, 3-(2-methyl-5-nitro-1-imidazolyl)-1, 2-propanediol; and M5, acetamide [10]. The pharmacodynamic results of levornidazole and its phase 1 metabolites indicated that M1 and M4 had similar antianaerobic activity to levornidazole in vitro [11]. Therefore, it is necessary to study the pharmacokinetics of these metabolites to examine whether they will influence the efficacy of levornidazole in vivo. The primary objective of this open-label, parallel, randomised, multidose trial was to investigate the pharmacokinetics and safety profile of levornidazole following two dosage regimens (750 mg q24h versus 500 mg q12h) in healthy Chinese volunteers. The secondary objective was to investigate the pharmacokinetics of levornidazole metabolites.
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2. Materials and methods
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2.1. Study design
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This was an open-label, parallel, randomised, multidose trial conducted at a single centre in China (Phase I Clinical Research Center at Huashan Hospital, Fudan University, Shanghai, China). The study cohort comprised 24 healthy Chinese subjects who were randomised to receive levornidazole sodium chloride injection 750 mg q24h (test group) or 500 mg q12h (reference regimen) via i.v. infusion. There were 12 subjects (6 males and 6 females) in each group. The study protocol and informed consent were approved by the Ethics Committee of Huashan Hospital, Fudan University, and the study was conducted according to the protocol, the Declaration of Helsinki, Good Clinical Practice and applicable local regulations. All subjects gave their written informed consent before study.
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2.2. Study subjects
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Healthy male or female Chinese adults aged 19–45 years with a body mass index (BMI) between 19 kg/m2 and 24 kg/m2 were included if their medical history, physical examination, electrocardiogram and clinical laboratory tests at screening did not reveal any abnormalities. Eligible subjects had a negative urine screen for alcohol or controlled drugs and were using an appropriate barrier method of birth control. Subjects were excluded if they had any of the following: a history of significant cardiovascular, hepatic, renal, haematological, neurological or psychiatric disorder; positive for antibody to human immunodeficiency virus (HIV), hepatitis B surface antigen, or antibody to hepatitis C virus; not satisfying the inclusion criteria for systolic blood pressure (≥90 mmHg and ≤140 mmHg), diastolic blood pressure (≥40 mmHg and ≤90 mmHg), pulse rate (≥40 per min and ≤99 per min) or QTc (≤450 ms); a history of drug allergy or drug abuse; donated blood or plasma >400 mL within 90 days of study initiation; participated in another clinical trial within 60 days prior to study entry; or received any prescription or overthe-counter medication within 14 days prior to study initiation. Subjects who could not tolerate levornidazole were also excluded.
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2.3. Drug administration
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subjects received a single dose of 750 mg (test group) or 500 mg (reference group) levornidazole at 07:00 h on Day 1 (first dose) and Day 11 (last dose). From Days 4 to 10, subjects in the test group were given 750 mg levornidazole once daily (07:00 h), whilst subjects in the reference group received 500 mg levornidazole twice daily (07:00 h and 19:00 h). The i.v. infusion of levornidazole was completed over 90 ± 10 min in the test group and over 60 ± 10 min in the reference group. 2.4. Blood and urine sample collection For the first and last doses of levornidazole, blood samples were drawn immediately before (0) and 0.33 h after the start of infusion, and immediately and 0.5, 1, 2, 4, 8, 12, 24, 36, 48, 60 and 72 h after the end of i.v. infusion. From Days 4 to 10, blood samples were drawn immediately before the start of the first infusion on Days 4, 8, 9 and 10, and immediately and 2, 6 and 12 h after the end of the first infusion on Day 8. Approximately 4 mL of blood was drawn each time. Plasma was separated and stored in polypropylene tubes at −40 ± 5 ◦ C until analysis. Urine samples were collected at the following time periods: −12 h to 0 h before administration of the first and last doses, and 0–4 h, 4–8 h, 8–12 h, 12–24 h, 24–48 h and 48–72 h after i.v. infusion of the first and last doses. After measurement of urine volume, a 4 mL urine sample was immediately stored in polypropylene tubes at −40 ± 5 ◦ C until analysis. 2.5. Laboratory assay The concentrations of levornidazole and its metabolites M1, M2 and M4 in plasma and urine were measured using a fully validated ultra-performance liquid chromatographic–tandem mass spectrometric (UPLC–MS/MS) method as described previously [12] and designed with reference to the US Food and Drug Administration (FDA) guidance for industry [13]. Levornidazole, M1, M2 and M4 were detectable with this method in the range of 0.0100–5.00, 0.00500–2.50, 0.0200–10.0 and 0.00250–1.25 g/mL. The lower limit of quantification (LLOQ) was 0.0100, 0.00500, 0.0200 and 0.00250 g/mL for levornidazole, M1, M2 and M4, respectively, both in plasma and urine. 2.6. Calculation of pharmacokinetic parameters The area under the plasma drug concentration–time curve during 0–24 h (AUC0–24 ) was calculated as AUC0–25.5 in the test group and 2 × AUC0–13 in the reference group. Maximum plasma concentration (Cmax ), terminal elimination half-life (t1/2 ), apparent volume of distribution (Vd ) and creatinine clearance (CLCr ) after the administration on Day 1 as well as the steadystate parameters Cmax ss , AUC0–24 ss , Vd ss and CLCr ss on Day 7 were estimated by non-compartmental analysis based on plasma concentrations of levornidazole, M1, M2 and M4 using Phoenix WinNonlin 6.0 software (Pharsight, Princeton, NJ). The accumulation ratio (AR = AUC0–24, Day 7 /AUC0–24, Day 1 ) of levornidazole, and the metabolite/parent ratio (MR = AUC0–24 metabolite / AUC0–24, parent drug × 100%) of metabolites were also calculated. The cumulative urinary excretion amount during 0–72 h, the cumulative urinary excretion rate and renal clearance rate were calculated. Compartmental analysis was also carried out using Phoenix WinNonlin 6.0 software to characterise the pharmacokinetics of levornidazole. 2.7. Safety evaluation
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Levornidazole 500 mg (volume 100 mL; lot 201210151, Sanhome Pharmaceutical Co. Ltd., Nanjing, China) was prepared in 100 mL of 0.9% sodium chloride for injection just prior to administration. Levornidazole was administered on the following schedule:
All subjects were included in the safety evaluation. The safety and tolerability profile of the two dosage regimens of levornidazole were assessed with the data for AEs, clinical laboratory tests,
Please cite this article in press as: Cao Y, et al. Improved pharmacokinetic profile of levornidazole following intravenous infusion of 750 mg every 24 h compared with 500 mg every 12 h in healthy Chinese volunteers. Int J Antimicrob Agents (2016), http://dx.doi.org/10.1016/j.ijantimicag.2015.12.007
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Table 1 Non-compartmental pharmacokinetic parameters of levornidazole and its metabolites following intravenous infusion of levornidazole 750 mg q24h versus 500 mg q12h in healthy Chinese volunteers.
Levornidazole
M1
M4
Dosage regimena
Parameter
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
t1/2 (h)
CLCr (L/h)
Cmax (g/mL)
AUC0–24 (h g/mL)
MR (%)
Day 1
Day 1
Day 7
Day 1
Day 7
Day 1
Day 7
Day 1
Day 1
Day 7
11.6 0.8 11.9 1.3 −0.474 0.640
2.96 0.56 2.90 0.51 0.275 0.786
2.70 0.63 2.60 0.43 0.441 0.664
49.3 9.1 50.0 8.6 0.096 0.924
22.9 4.8 33.2 4.8 −5.14 0.000
12.5 3.4 17.3 2.2 −4.10 0.000
22.3 5.3 22.1 3.2 0.082 0.936
88.7 196 16.8 52 201 295 32 45 −10.9 −4.86 0.000 0.000
N/A
N/A
N/A
N/A
N/A
N/A
11.8 1.5 12.5 2.4 −0.310 0.759
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
0.477 0.255 0.296 0.140 2.13 0.048
1.14 0.41 2.86 1.14 −4.94 0.000
5.62 3.07 6.21 3.00 −0.463 0.648
2.06 0.55 1.63 0.45 2.06 0.052
3.15 1.09 2.18 0.77 2.43 0.024
N/A
N/A
0.118 0.043 0.150 0.060 −1.50 0.147
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
0.432 0.099 0.348 0.055 2.49 0.021
1.44 0.34 3.86 0.58 −12.5 0.000
4.86 1.16 7.38 1.24 −5.05 0.000
2.58 0.13 2.47 0.39 0.896 0.386
3.18 0.34 2.94 0.37 1.65 0.114
N/A
N/A
0.131 0.027 0.184 0.030 −4.56 0.000
12.1 1.2 14.2 3.1 −2.22 0.037
Vd (L)
Day 7
AR
2.19 0.30 1.45 0.16 7.33 0.000
N/A N/A
N/A N/A
q24h, every 24 h; q12h, every 12 h; t1/2 , terminal elimination half-life; CLCr , creatinine clearance; Vd , apparent volume of distribution; Cmax , maximum plasma concentration; AUC0–24 , area under the plasma concentration–time curve during 0–24 h (500 mg q12h: 2 × AUC0–13 ; 750 mg q24h: AUC0–25.5 ); MR, metabolite/parent ratio (=AUC0–24, metabolite /AUC0–24, parent drug × 100%); AR, accumulation ratio (=AUC0–24, Day 7 /AUC0–24, Day 1 ); S.D., standard deviation; N/A, not available. a 500 mg q12h dosage regimen: n = 12; 750 mg q24h dosage regimen: n = 12 on Day 1, n = 11 on Day 7 (1 subject was withdrawn from the study 24 h after the first dose). b Independent sample t-test.
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vital signs, electrocardiogram and physical examination. Laboratory tests were conducted on the screening day, Day −1, Days 1, 4 and 8 before infusion of the first dose, and Day 14 before leaving the ward. 2.8. Statistical analysis The pharmacokinetic parameters and urinary excretion parameters were summarised using descriptive statistics. The independent sample t-test was used to evaluate the difference between test group and reference group. P < 0.05 was considered statistically significant.
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3. Results
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3.1. Patient characteristics
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A total of 24 healthy Chinese subjects were enrolled. Subjects in the test group and the reference group had a mean ± standard deviation age of 24.25 ± 2.53 years and 23.75 ± 1.71 years, respectively, and mean BMI of 22.03 ± 1.63 kg/m2 and 21.86 ± 1.53 kg/m2 , respectively. The demographic characteristics were balanced between groups. All subjects completed the trial, except for one subject in test group who was withdrawn on Day 2 owing to apical periodontal abscess and increased neutrophils.
3.2. Pharmacokinetic parameters
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The plasma concentration–time curves of levornidazole are presented in Supplementary Fig. S1. The profile of levornidazole, M1 and M4 was similar in both groups. The plasma concentration of M2 was almost lower than the LLOQ (0.0200 g/mL) in both groups. The results of non-compartmental pharmacokinetic analysis based on the plasma concentrations of levornidazole, M1 and M4 are presented in Table 1. The t1/2 , CLCr and Vd of levornidazole on Day 1 were similar between the two dose groups, whilst Cmax and AUC0–24 were significantly higher in the test group (P < 0.05). The Cmax ss on Day 7 did not show a significant difference between the two groups, although AUC0–24 ss in the test group was 50.5% higher than that in reference group. The AR of levornidazole was 1.45 ± 0.16 in the test group, which is 33.8% lower than that in the reference group (2.19 ± 0.30). The Vd ss of levornidazole in the test group was 45.0% higher than that in reference group. The MR of M1 and M4 was, respectively, 2.18 ± 0.77% and 2.94 ± 0.37% in the test group and 3.15 ± 1.09% and 3.18 ± 0.34% in the reference group. Compartmental analysis demonstrated that a two-compartment model (r = 1/C) was well fitted with the observed concentrations of levornidazole (see Table 2 and Supplementary Fig. S2). Urinary excretion parameters of levornidazole, M1, M2 and M4 are presented in Table 3. The urinary excretion parameters
Table 2 Two-compartmental pharmacokinetic parameters of levornidazole following intravenous infusion of 750 mg q24h versus 500 mg q12h in healthy Chinese volunteers. Dosage regimena
Parameter
V1 (L)
V2 (L)
k10 (1/h)
k12 (1/h)
k21 (1/h)
t1/2 ␣ (h)
t1/2  (h)
CL (L/h)
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
29.47 11.10 28.34 12.50 0.234 0.419
20.12 10.57 21.17 16.15 −0.187 0.066
0.110 0.036 0.120 0.053 −0.496 0.133
5.10 3.46 4.77 3.38 0.243 0.859
6.45 1.91 6.58 2.87 −0.122 0.018
0.074 0.054 0.062 0.010 0.725 0.090
12.04 1.29 12.30 1.67 −0.421 0.473
2.92 0.64 2.85 0.57 0.273 0.490
q24h, every 24 h; q12h, every 12 h; V1 , volume of distribution of central compartment; V2 , volume of distribution of peripheral compartment; k10 , elimination rate constant leaving central compartment; k12 , transfer rate constant from central compartment to peripheral compartment; k21 , transfer rate constant from peripheral compartment to central compartment; t1/2 ␣ , distribution phase half-life; t1/2  , elimination phase half-life; CL, clearance from central compartment; S.D., standard deviation. a 500 mg q12h: n = 12; 750 mg q24h: n = 12 on Day 1, n = 11 on Day 7 (1 subject was withdrawn 24 h after the first dose). b Independent sample t-test.
Please cite this article in press as: Cao Y, et al. Improved pharmacokinetic profile of levornidazole following intravenous infusion of 750 mg every 24 h compared with 500 mg every 12 h in healthy Chinese volunteers. Int J Antimicrob Agents (2016), http://dx.doi.org/10.1016/j.ijantimicag.2015.12.007
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Table 3 Urinary excretion parameters of levornidazole and its metabolites M1, M2 and M4 following intravenous infusion of levornidazole 750 mg q24h or 500 mg q12h for 7 days in healthy Chinese volunteers. Dosage regimena
Parameter
Day 1 Ratemax (mg/h)
Day 7 Ae0–72 (%)
CLr (L/h)
Ratemax (mg/h)
Ae0–72 (%)
CLr (L/h)
0.283 0.075 0.269 0.097 0.396 0.696
10.5 3.0 13.3 24.3 −0.393 0.699
24.2 5.7 16.6 20.9 1.20 0.242
0.335 0.083 0.306 0.313 0.310 0.761
1.08 0.41 1.37 2.82 −0.345 0.733
3.67 1.44 2.71 3.95 0.789 0.439
N/A
0.07 0.03 0.03 0.02 3.51 0.002
N/A
7.30 0.94 4.51 5.69 1.67 0.109
N/A
Levornidazole
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
3.29 1.41 5.11 2.31 −2.33 0.031
9.56 2.15 9.32 3.51 0.206 0.839
M1
500 mg q12h
Mean S.D. Mean S.D.
0.213 0.059 0.342 0.148 −2.80 0.014
1.05 0.28 1.03 0.50 −0.140 0.887
N/A
0.00 0.00 0.01 0.01 1.19 0.247
N/A
N/A
N/A
N/A
N/A
N/A
2.62 0.27 1.97 0.99 2.20 0.039
N/A
2.01 0.25 2.09 3.8 −0.068 0.946
750 mg q24h tb P-value M2
M4
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
500 mg q12h 750 mg q24h tb P-value
Mean S.D. Mean S.D.
N/A N/A N/A 0.471 0.027 0.571 0.305 −1.13 0.271
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A
q24h, every 24 h; q12h, every 12 h; Ratemax , maximum excretion rate in urine; Ae0–72 , cumulative urinary excretion rate during 0–72 h period; CLr , renal clearance; S.D., standard deviation; N/A, not available. a 500 mg q12h: n = 12; 750 mg q24h: n = 12 on Day 1, n = 11 on Day 7 (1 subject was withdrawn 24 h after the first dose). b Independent sample t-test.
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of levornidazole, M1 and M4 did not show a significant difference between the two groups.
3.3. Safety profile Following i.v. infusion of multiple doses of levornidazole, AEs were observed in 8 (33.3%) of the 24 subjects. All of the study drugrelated AEs were laboratory abnormalities (Supplementary Table S1), including three AEs in the test group and five AEs in the reference group (P > 0.05). These events were mild or moderate and resolved by the end of the study. No serious AEs were observed during the study. One subject in the test group was withdrawn on Day 2 owing to apical periodontal abscess and increased neutrophils. This subject was treated with concomitant medications. The investigator considered that this event was unrelated to the study medication.
4. Discussion The observed pharmacokinetic parameters following i.v. infusion of 500 mg levornidazole q12h in this study are consistent with previous studies [6]. Following i.v. infusion of multiple doses of levornidazole, the non-compartmental pharmacokinetic parameters AUC0–∞ and Cmax ss were comparable between the 750 mg q24h dose group and the 500 mg q12h dose group. However, the Vd ss of levornidazole was 45.0% higher and the AR was 33.8% lower than the values in the 500 mg q12h dose group. These data confirm that 750 mg q24h of levornidazole results in lower accumulation of levornidazole in vivo compared with the conventional 500 mg q12h regimen. This finding is supported by the plasma concentration–time curves in Supplementary Fig. S1.
Safety evaluation indicated that the incidence of abnormal liver function test AEs in the 750 mg q24h group was similar to those in the 500 mg q12h group. No serious AEs occurred in any group. The plasma concentration–time curves of M1 and M4 were similar to levornidazole. The MR of M1, M2 and M4 were all <5%. Pharmacodynamic studies of levornidazole and its phase 1 metabolites have shown that M1 and M4 have in vitro anti-anaerobic activity similar to levornidazole [11]. However, the metabolites may not influence the anti-anaerobic activity of levornidazole due to low MR in vivo. Only 24 healthy subjects were enrolled in this study. The sample size is limited. These preliminary results and conclusion should be further confirmed in a larger cohort of patients with pelvic anaerobic infections or other target patients. It is reported that levornidazole shows a concentrationdependent antibacterial property against Bacteroides fragilis in vitro using time–kill assay and sigmoid Emax model analysis [14]. We will design a further study to examine the pharmacokinetic/pharmacodynamic target values of levornidazole for treatment of B. fragilis infections. In conclusion, i.v. infusion of multiple doses of levornidazole 750 mg q24h has the advantages of a lower AR in vivo and a good safety profile compared with the conventional 500 mg q12h regimen. Therefore, a levornidazole 750 mg q24h dosage regimen can also be recommended for clinical treatment. Acknowledgments The authors would like to thank Nanjing Sanhome Pharmaceutical Co., Ltd. for their help in this study.
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Funding: This work was supported by the New Drug Creation and Q4 Manufacturing Program of the Ministry of Science and Technology of China [2012ZX09104101; 2012ZX09303004-001].
Please cite this article in press as: Cao Y, et al. Improved pharmacokinetic profile of levornidazole following intravenous infusion of 750 mg every 24 h compared with 500 mg every 12 h in healthy Chinese volunteers. Int J Antimicrob Agents (2016), http://dx.doi.org/10.1016/j.ijantimicag.2015.12.007
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Competing interests: Nanjing Sanhome Pharmaceutical Co., Ltd. provided the study drug levornidazole used in this study.
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Ethical approval: This study was approved by the Ethics Committee of Huashan Hospital, Fudan University (Shanghai, China) [approval no. 2012-222].
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Appendix A. Supplementary data
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Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.ijantimicag.2015. 12.007.
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References
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[1] López Nigro MM, Palermo AM, Mudry MD, Carballo MA. Cytogenetic evaluation of two nitroimidazole derivatives. Toxicol. In Vitro 2003;17:35–40. [2] Li HM, Mei YN, Xu D. In vitro antibacterial activity of ornidazole against 111 clinical isolates of anaerobes. Acta Univ. Med. Nanjing 2008;28:1500–2 (in Chinese). [3] Sun JH, Wang ZQ, Gu XL, Mu R. Comparative study of ornidazole enantiomers on the toxic and side effects to central nervous system in mice. J. China Pharm. Univ 2008;39:343–7 (in Chinese). [4] Mu LL, Cheng ZN, Guo X, Luo X, Yu P. Investigation of chiral inversion and pharmacokinetics of laevo-ornidazole by high-performance liquid chromatography. J. Clin. Pharm. Ther 2013;38:31–5.
5
[5] Chen Y, Liu XQ, Zhong J, Zhao X, Wang Y, Wang G. Stereoselective pharmacokinetics of ornidazole after intravenous administration of individual enantiomers and the racemate. Chirality 2006;18:799–802. [6] Wang H, Hao K, Wang GJ. Determination of the resistant mutant-preventing concentrations of four antimicrobial agents including levornidazole and justification of clinical dosage. Prog. Pharmaceut. Sci 2012;6:277–81. [7] Ma L, Zhang YZ, Zheng YL, Wang ZH, Xu YD, Kong LN. Multicenter randomized controlled clinical study on levornidazole and sodium chloride injection in the treatment of pelvic anaerobic infections. Zhonghua Fu Chan Ke Za Zhi 2010;45:754–6 (in Chinese). [8] Chen S, Zhang HD, Wang YC, Lou DH, Tao XX. Efficacy of levornidazole sodium chloride injection in treating oral anaerobic infections. Jiangsu Med. J 2011;37:714–5 (in Chinese). [9] Zhao YN, Wu P, Sun H. Human tolerability and pharmacokinetic studies of levornidazole by dose escalation. Chin. Pharm. J 2011;46:454–7 (in Chinese). [10] Schwartz DE, Jordan JC, Vetter W, Oesterhelt G. Metabolic studies of ornidazole in the rat, in the dog and in man. Xenobiotica 1979;9:571–81. [11] Hu J, Zhang J, Wu S, Zhu D, Huang H, Chen Y, et al. Evaluation of the in vitro activity of levornidazole, its metabolites and comparators against clinical anaerobic bacteria. Int. J. Antimicrob. Agents 2014;44:514–9. [12] Cao Y, Zhao M, Wu X, Guo B, Chen Y, Yu J, et al. Quantification of levornidazole and its metabolites in human plasma and urine by ultra-performance liquid chromatography–mass spectrometry. J. Chromatogr. B: Analyt. Technol. Biomed. Life Sci 2014;963:119–27. [13] US Food and Drug Administration. Guidance for Industry, Bioanalytical Method Validation. Rockville, MD: US Department of Health and Human Services, Food and Drug Administration; 2001. http://www.fda.gov/downloads/Drugs/ GuidanceComplianceRegulatoryInformation/Guidances/ucm070107.pdf [accessed July 2012]. [14] Hu JL, Zhang J, Chen YC, Wu S, Zhu DM, Yang Y, Zhang YY. In vitro bactericidal property of levornidazole against Bacteroides fragilis studied by time-kill assay and sigmoid Emax model analysis. Int. J. Antimicrob. Agents 2015;45:673–5.
Please cite this article in press as: Cao Y, et al. Improved pharmacokinetic profile of levornidazole following intravenous infusion of 750 mg every 24 h compared with 500 mg every 12 h in healthy Chinese volunteers. Int J Antimicrob Agents (2016), http://dx.doi.org/10.1016/j.ijantimicag.2015.12.007
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