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Relationship between vitamin K1 2,3-epoxide and vitamin K1 in patients treated with N-methyl-thiotetrazole cephalosporins
THROMBOSIS RESEARCH 65; 439-442,1992 0049-3848/92 $5.00 + .OO Printed in the USA. Copyright (c) 1992 Pergamon Press Ltd. All rights reserved.
BRIEF
COMMUNICATION
RELATIONSHIP BETWEEN VITAMIN K12,3-EPOXIDE AND VITAMIN K1 IN PATIENTS TREATED WITH N-METHYL-THIOTETRAZOLE CEPI-IALOSPORINS
Helmut Schafer and F.R. Matthias Centre for Clinical Trials, University of Heidelberg, Im Neuenheimer Feld 305, D-W6900 Heidelberg, and Centre for Internal Medicine, University of GiefSen (Received
1.7.1991;
accepted
in revised form 22.11.1991
by Editor F. Markwardt)
INTRODUCTION Since 1980, several cases of hypoprothrombinemia in patients treated with cephalosporins with an N-methyl-thiotetrazole (NMTT) side chain, such as latamoxef and cefoperazone, were reported (s. [l] for references). The effect only occurs in malnourished or debilitated patients and cannot be induced in healthy volunteers eating a normal diet 121. A prolonged prothrombin time can be normalized by administration of vitamin Kl 131 141. Several mechanisms of action were discussed: (1) a reduction of vitamin K producing colonic micro-flora [2], (2) an inhibition of g-carboxylation of clotting factors in the liver [S], and (3) an inhibition of hepatic vitamin K-epoxide reductase [4] by the NMTT side chain. While mechanism (2) must be questioned in view of the results of Shearer et al. [6], (1) and (3) may act in union. In the present note, we are dealing with mechanism (3). Shearer et al. [41 observed the plasma appearance of vitamin KI 2,3-epoxide in patients with NMTT-induced hypoprothrombinemia. This indicates an impaired hepatocellular regeneration of vitamin KI from the epoxide, which is supposed to lower the effective concentration of vitamin K at the relevant site and to cause depression of vitamin K - dependent procoagulants [41.In none of the previous clinical trials, significant differences in plasma vitamin KI before and during cephalosporin therapy were observed [41.In the present note, we report on unexpected vitamin K findings in a randomized clinical trial, in which plasma vitamin K concentrations were
Key words: NMTT cephalosporins,
vitamin K metabolism, hypoprothrombinemia 439
440
NMTT
CEPHALOSPORINS
AND VITAMIN
K
Vol. 65, No. 3
measured as a secondary parameter. The primary results of this trial and details on the study protocol can be found in 111. MATERIAL AND METHODS In a randomized clinical trial [l], 14 hospitalized patients with urinary tract infections were treated with latamoxef (n=S, daily dosis 2 x 2 s>, cefoperazone (n=5, daily dosis 2 x 2 g) or, as a control, cefotaxime (n=4, daily dosis 3 x 2 g). The main inclusion criteria were patient’s informed consent, age > 60 years, and normal prothrombin time. Patients treated with substances which may interfere with vitamin K metabolism or plasmatic coagulation during the last four weeks prior to randomization were excluded. Among other parameters of the plasmatic coagulation system, vitamin KI 2,3epoxide and vitamin Ki plasma levels were measured before and after 7 days of treatment, in plasma ethanol-hexane extracts using electron-capture gas-liquid capillary chromatography as described in [7]. With this method, the chromatogram shows a complete baseline separation between vitamin Kl, cis-vitamin Kl 2,3epoxide and trans-vitamin KI 2,3-epoxide [7]. Detection threshold for vitamin KI and its epoxide were 5-10 ng/ml. The coefficients of variation for replicate analyses were 12% for vitamin KI and 15% for its epoxide. All plasma samples were analysed in the same run. The values respresent circulating endogenous vitamin K and vitamin K-epoxide. In contrast to [4], no stimulation by vitamin K injection was used. For the present analysis, patients were regrouped according to whether vitamin Kl 2,3-epoxide did appear (group EPOX) or did not appear (group NO EPOX). Changes of vitamin K levels under therapy (difference after minus before therapy) were compared between these two groups. RESULTS The distributions of plasma vitamin K levels were equal in both groups before onset of therapy. In patients without appearance of vitamin K-epoxide, vitamin K levels only showed the spontaneous intra-individual variability under therapy, i.e. they remained unchanged in the mean (group NO EF’OX:n=7, mean change = -0,011 ng/ml, standard deviation s=O,O79).In contrast, there was an increase in the mean vitamin K level of the patients with appearance of vitamin K-epoxide (group EPOX: n=7, mean change = +0,234 ng/ml, s=O,lSP). The effect cannot be identified for every individual patient, but the mean increase was statistically significant, not only with respect to the baseline values before onset of therapy, but also compared to the NON EPOX group (p=O,OO233for a two-tailed permutation test). The medical records of all patients were checked with respect to additional vitamin K intake. Patients no 6 and 10 (both on cefoperazone, marked by dotted lines in figure 1) had received 500 ml of liquid parenteral nutrition containing 10 mg of vitamin K1 (Fresubin@). Exclusion of these patients did not substantially change the result (group EPOX: n=5, mean change of vitamin K levels = +0,208 ng/ml,
Vol. 65, No. 3
NMTT CEPHALOSPORINS
AND VITAMIN K
441
s=O,O97; group NO EPOX: as before; p=O,OO505). Remarkably, the only two patients
who developped relevant hypoprothrombinemia (patients no 10 and 14, decrease of Quick value to less than 50 % as stipulated in the study protocol), at the same time showed the most marked vitamin K increase.
ng/ml 0,60 4
0,oo
f-
p IO.005
NO EPOX
t
//
EPOX
Figure 1: Plasma vitamin K1 levels before and after 7 days of treatment with cephalosporins. A / B / C = cefotaxime / cefoperazone / latamoxef. NO EPOX / EPOX = patients without/with appearance of vitamin Kl2,3-epoxide. (Dotted lines: patients received parenteral nutrition containing 10 mg of vitamin KI during therapy. Exclusion of these patients doesn’t change the statistical significance.)
DISCUSSION According to the mechanism of action described in the introduction, one might expect a tendency to decreasing plasma vitamin K levels in patients with appearance of vitamin KI 2,3-epoxide after treatment with NMTT cephalosporins. In contrast, in the present study, the appearance of the epoxide was associated with an increase rather than a decrease of the mean plasma vitamin K level. We do not want to offer possible explanations for this effect. Note that what we point to is the change of vitamin K levels under therapy. More precisely, in our data there is a positive correlation between the differences (after minus before therapy) of vitamin K-epoxide levels and the differences of vitamin K levels. As a consequence, our data also show a positive correlation between vitamin K and vitamin K epoxide levels after therapy. The last-mentioned correlation per se would clearly not be unexpected and does not contradict the supposed mechanism (see 181, fig. 10). It should be emphasized that the reported result is based on a secondary analysis of the data, regrouping patients by vitamin Kl 2,3-epoxide appearance. Thus, in spite of the high nominal statistical significance, the reported association cannot be taken as confirmatory and needs further investigation. Finally, we remark that the epoxide was not detected in all the patients treated with one of the two NMl’T cephalosporins (see the three exceptions in figure 1: patients
442
NMTT CEPHALOSPORINS
ANDVlTAMtNK
Vol. 65, .No.3
no 7C, 88, 13C). At first sight, this seems to be in contrast to the findings of previous studies [41. However, there is an important difference in the methods: The present study is the first in which circulating endogenous vitamin K epoxide was measured, while in the other studies a previous stimulation by injection of 10 mg of vitamin K had been used. ACKNOWLEDGEMENT This study was sponsored by Eli Lilly GmbH, Bad Homburg v.d.H., Hoechst AG, Frankfurt, and Shionogi & Co. Ltd., Dusseldorf. It was supervised by the Paul Ehrlich Society (President: Prof. Dr. Dr. D. Adam). REFERENCES [ll SCHAFER H, NABER K, ADAM D: Himostasestiirungen bei Cephalosporinen mit einer N-Methyl-thiotetrazol-Seitenkette. Eine randomisierte Pilotstudie. Arzneim. Forsch./Drug Res. 39, 1156-1162 (1989). 121 BANG NU, TESSLER SS, HEIDENREICH RO, MARKS CA, MATTLER LE: Effects of moxalactam on blood coagulation and platelet function. Rev infect Dis 4 (suppl.): S546-S554 (1982). 131 FAINSTEIN V, BODEY G, MCCREDIE K, KEATING M, ESTEY E, BOLIVAR R, ELTING L: Coagulation abnormalities induced by beta lactam antibiotics in cancer patients. ] Infect Dis 148, 745-750 (1983) [4] SHEARER Ml, BECHTHOLD H, ANDRASSY K, KODERISCH J, MCCARTHY PT, TRENK D, JAHNCHEN E, RITZ E: Mechanism of Cephalosporin-induced Relation to Cephalosporin Side Chain, Vitamin K Hypoprotrombinemia: Metabolism, and Vitamin K Status. 1 Clin Pharmacol28, 88-95 (1988). inhibition of the gamma carboxylation [fl LIPSKY JJ: N- methyl-thio-tetrazole glutamic acid: Possible mechanism for antibiotic-associated hypoprothrombinaemia. Lancer II: 192-193 (1983). [61 SUTTIE JW, ENGELKE JA, MCTIQUE J: Effect of N-methyl-thiotetrazole on rat liver microsomal vitamin K - dependent carboxylation. Biochem Pharmacol 35, 2429-2433 (1986) [71 BECHTHOLD H, KLEIN, F, TRENK D, JAHNCHEN E: Improved method for quantitative analysis of vitamin K1 and vitamin Kl 2,3-epoxide in human plasma by electron-capture gas-liquid capillary chromatography. J Chromtogr 306, 33-37 (1984). [S] UCHIDA, K, KOMENO, T: Relationships between dietary and intestinal vitamin K, clotting factor levels, plasma vitamin K and urinary gla. In: John W. Suttie, Current advances in Vitamin K research, Elsevier Science Publishing Co. 1988.
BRIEF
COMMUNICATION
RELATIONSHIP BETWEEN VITAMIN K12,3-EPOXIDE AND VITAMIN K1 IN PATIENTS TREATED WITH N-METHYL-THIOTETRAZOLE CEPI-IALOSPORINS
Helmut Schafer and F.R. Matthias Centre for Clinical Trials, University of Heidelberg, Im Neuenheimer Feld 305, D-W6900 Heidelberg, and Centre for Internal Medicine, University of GiefSen (Received
1.7.1991;
accepted
in revised form 22.11.1991
by Editor F. Markwardt)
INTRODUCTION Since 1980, several cases of hypoprothrombinemia in patients treated with cephalosporins with an N-methyl-thiotetrazole (NMTT) side chain, such as latamoxef and cefoperazone, were reported (s. [l] for references). The effect only occurs in malnourished or debilitated patients and cannot be induced in healthy volunteers eating a normal diet 121. A prolonged prothrombin time can be normalized by administration of vitamin Kl 131 141. Several mechanisms of action were discussed: (1) a reduction of vitamin K producing colonic micro-flora [2], (2) an inhibition of g-carboxylation of clotting factors in the liver [S], and (3) an inhibition of hepatic vitamin K-epoxide reductase [4] by the NMTT side chain. While mechanism (2) must be questioned in view of the results of Shearer et al. [6], (1) and (3) may act in union. In the present note, we are dealing with mechanism (3). Shearer et al. [41 observed the plasma appearance of vitamin KI 2,3-epoxide in patients with NMTT-induced hypoprothrombinemia. This indicates an impaired hepatocellular regeneration of vitamin KI from the epoxide, which is supposed to lower the effective concentration of vitamin K at the relevant site and to cause depression of vitamin K - dependent procoagulants [41.In none of the previous clinical trials, significant differences in plasma vitamin KI before and during cephalosporin therapy were observed [41.In the present note, we report on unexpected vitamin K findings in a randomized clinical trial, in which plasma vitamin K concentrations were
Key words: NMTT cephalosporins,
vitamin K metabolism, hypoprothrombinemia 439
440
NMTT
CEPHALOSPORINS
AND VITAMIN
K
Vol. 65, No. 3
measured as a secondary parameter. The primary results of this trial and details on the study protocol can be found in 111. MATERIAL AND METHODS In a randomized clinical trial [l], 14 hospitalized patients with urinary tract infections were treated with latamoxef (n=S, daily dosis 2 x 2 s>, cefoperazone (n=5, daily dosis 2 x 2 g) or, as a control, cefotaxime (n=4, daily dosis 3 x 2 g). The main inclusion criteria were patient’s informed consent, age > 60 years, and normal prothrombin time. Patients treated with substances which may interfere with vitamin K metabolism or plasmatic coagulation during the last four weeks prior to randomization were excluded. Among other parameters of the plasmatic coagulation system, vitamin KI 2,3epoxide and vitamin Ki plasma levels were measured before and after 7 days of treatment, in plasma ethanol-hexane extracts using electron-capture gas-liquid capillary chromatography as described in [7]. With this method, the chromatogram shows a complete baseline separation between vitamin Kl, cis-vitamin Kl 2,3epoxide and trans-vitamin KI 2,3-epoxide [7]. Detection threshold for vitamin KI and its epoxide were 5-10 ng/ml. The coefficients of variation for replicate analyses were 12% for vitamin KI and 15% for its epoxide. All plasma samples were analysed in the same run. The values respresent circulating endogenous vitamin K and vitamin K-epoxide. In contrast to [4], no stimulation by vitamin K injection was used. For the present analysis, patients were regrouped according to whether vitamin Kl 2,3-epoxide did appear (group EPOX) or did not appear (group NO EPOX). Changes of vitamin K levels under therapy (difference after minus before therapy) were compared between these two groups. RESULTS The distributions of plasma vitamin K levels were equal in both groups before onset of therapy. In patients without appearance of vitamin K-epoxide, vitamin K levels only showed the spontaneous intra-individual variability under therapy, i.e. they remained unchanged in the mean (group NO EF’OX:n=7, mean change = -0,011 ng/ml, standard deviation s=O,O79).In contrast, there was an increase in the mean vitamin K level of the patients with appearance of vitamin K-epoxide (group EPOX: n=7, mean change = +0,234 ng/ml, s=O,lSP). The effect cannot be identified for every individual patient, but the mean increase was statistically significant, not only with respect to the baseline values before onset of therapy, but also compared to the NON EPOX group (p=O,OO233for a two-tailed permutation test). The medical records of all patients were checked with respect to additional vitamin K intake. Patients no 6 and 10 (both on cefoperazone, marked by dotted lines in figure 1) had received 500 ml of liquid parenteral nutrition containing 10 mg of vitamin K1 (Fresubin@). Exclusion of these patients did not substantially change the result (group EPOX: n=5, mean change of vitamin K levels = +0,208 ng/ml,
Vol. 65, No. 3
NMTT CEPHALOSPORINS
AND VITAMIN K
441
s=O,O97; group NO EPOX: as before; p=O,OO505). Remarkably, the only two patients
who developped relevant hypoprothrombinemia (patients no 10 and 14, decrease of Quick value to less than 50 % as stipulated in the study protocol), at the same time showed the most marked vitamin K increase.
ng/ml 0,60 4
0,oo
f-
p IO.005
NO EPOX
t
//
EPOX
Figure 1: Plasma vitamin K1 levels before and after 7 days of treatment with cephalosporins. A / B / C = cefotaxime / cefoperazone / latamoxef. NO EPOX / EPOX = patients without/with appearance of vitamin Kl2,3-epoxide. (Dotted lines: patients received parenteral nutrition containing 10 mg of vitamin KI during therapy. Exclusion of these patients doesn’t change the statistical significance.)
DISCUSSION According to the mechanism of action described in the introduction, one might expect a tendency to decreasing plasma vitamin K levels in patients with appearance of vitamin KI 2,3-epoxide after treatment with NMTT cephalosporins. In contrast, in the present study, the appearance of the epoxide was associated with an increase rather than a decrease of the mean plasma vitamin K level. We do not want to offer possible explanations for this effect. Note that what we point to is the change of vitamin K levels under therapy. More precisely, in our data there is a positive correlation between the differences (after minus before therapy) of vitamin K-epoxide levels and the differences of vitamin K levels. As a consequence, our data also show a positive correlation between vitamin K and vitamin K epoxide levels after therapy. The last-mentioned correlation per se would clearly not be unexpected and does not contradict the supposed mechanism (see 181, fig. 10). It should be emphasized that the reported result is based on a secondary analysis of the data, regrouping patients by vitamin Kl 2,3-epoxide appearance. Thus, in spite of the high nominal statistical significance, the reported association cannot be taken as confirmatory and needs further investigation. Finally, we remark that the epoxide was not detected in all the patients treated with one of the two NMl’T cephalosporins (see the three exceptions in figure 1: patients
442
NMTT CEPHALOSPORINS
ANDVlTAMtNK
Vol. 65, .No.3
no 7C, 88, 13C). At first sight, this seems to be in contrast to the findings of previous studies [41. However, there is an important difference in the methods: The present study is the first in which circulating endogenous vitamin K epoxide was measured, while in the other studies a previous stimulation by injection of 10 mg of vitamin K had been used. ACKNOWLEDGEMENT This study was sponsored by Eli Lilly GmbH, Bad Homburg v.d.H., Hoechst AG, Frankfurt, and Shionogi & Co. Ltd., Dusseldorf. It was supervised by the Paul Ehrlich Society (President: Prof. Dr. Dr. D. Adam). REFERENCES [ll SCHAFER H, NABER K, ADAM D: Himostasestiirungen bei Cephalosporinen mit einer N-Methyl-thiotetrazol-Seitenkette. Eine randomisierte Pilotstudie. Arzneim. Forsch./Drug Res. 39, 1156-1162 (1989). 121 BANG NU, TESSLER SS, HEIDENREICH RO, MARKS CA, MATTLER LE: Effects of moxalactam on blood coagulation and platelet function. Rev infect Dis 4 (suppl.): S546-S554 (1982). 131 FAINSTEIN V, BODEY G, MCCREDIE K, KEATING M, ESTEY E, BOLIVAR R, ELTING L: Coagulation abnormalities induced by beta lactam antibiotics in cancer patients. ] Infect Dis 148, 745-750 (1983) [4] SHEARER Ml, BECHTHOLD H, ANDRASSY K, KODERISCH J, MCCARTHY PT, TRENK D, JAHNCHEN E, RITZ E: Mechanism of Cephalosporin-induced Relation to Cephalosporin Side Chain, Vitamin K Hypoprotrombinemia: Metabolism, and Vitamin K Status. 1 Clin Pharmacol28, 88-95 (1988). inhibition of the gamma carboxylation [fl LIPSKY JJ: N- methyl-thio-tetrazole glutamic acid: Possible mechanism for antibiotic-associated hypoprothrombinaemia. Lancer II: 192-193 (1983). [61 SUTTIE JW, ENGELKE JA, MCTIQUE J: Effect of N-methyl-thiotetrazole on rat liver microsomal vitamin K - dependent carboxylation. Biochem Pharmacol 35, 2429-2433 (1986) [71 BECHTHOLD H, KLEIN, F, TRENK D, JAHNCHEN E: Improved method for quantitative analysis of vitamin K1 and vitamin Kl 2,3-epoxide in human plasma by electron-capture gas-liquid capillary chromatography. J Chromtogr 306, 33-37 (1984). [S] UCHIDA, K, KOMENO, T: Relationships between dietary and intestinal vitamin K, clotting factor levels, plasma vitamin K and urinary gla. In: John W. Suttie, Current advances in Vitamin K research, Elsevier Science Publishing Co. 1988.