Visceral leishmaniasis unresponsive to antimonial drugs III. Successful treatment using a combination of sodium stibogluconate plus allopurinol

TRAN~AC?.IONS OF THE ROYAL SOCIETY OF TROPICAL MED~NE

AND HYGIENE (1985) 79, 715.718

715

Visceral leishmaniasis unresponsive to antimonial drugs III. Successful treatment using a combination of sodium stibogluconate plus allopurinol C. N. CHUNGE,’ G. GACHIHI’ R. MUIGAI’, K. WASUNNA’, J. R. RASHID,’ J. D. CHULAY,“** G. ANABWANI,“~ C. N. OSTER’~’ AND A. D. M. BRYCESON’** ‘Clinical Research Centre, Kenya Medical Research Institute, P.O. Box 20778, Nairobi, Kenya; ‘US Army Medical Research Unit-Kenya; 3Departmmt of Paediatrics, College of Health Sciences, University of Nairobi, Kenya

Abstract

Five patients with long-standing visceral leishmaniasis who were unresponsive to sodium stibogluconate, 20 mg antimony/kg body-weight once or twice daily, were treated for 14 to 54 days with a combination of sodium stibogluconate at the samedose plus allopurinol at a dose of 20 mgikg body-weight per day in three divided doses.This combination was safeand effective. Negative splenic aspirate smearswere obtained from all patients within 19 days, and none has relapsed in at least 12 months of follow-up. Introduction

The drun of choice to treat visceral leishmaniasis in Kenya is -the pentavalent antimonial compound sodium stiboeluconate O’entostam.(R) Wellcome. UK). At a d&e of 10 ml: antimon; (Sb)/kg body: weight (bw) for 30 days, it achievesan initial cure rate of 95% (MANSON-BAHR, 1959; CHULAY et al., 1983b), but relapses are common, averaging 21% (WIJERS, 1971). A small proportion of patients become unresponsive to conventional doses of antimonials, usually after repeated treatment of relapses (BRYCESON et al., 1985a). Some of these patients respond to higher doses of antimonials, but toxicity wiih very high doses usually precludes an adequate duration of such theraov (BRYCESON et al., 1985b). Alternating or combin& tieatment with per&mid&e has some6mes achieved cures (BRYCE?ON et al., 1985bj. but comolications resulting from oentamidine (CHUG&Eet al.,*1984) have disco&aged its use. The use of amphotericin B is not feasible because of its toxicity and unavailability in Kenya. In 15181KAGER et al. reported on the use of allopurinol in visceral leishmaniasis in Kenya. When allopurinol was used alone, there was usually clinical and haematological improvement during treatment, but initial parasitological cure was achieved in only 3 of 10 patients. Another five patients responded to combined treatment with allopurinol plus sodium stibogluconate, although their response to sodium stibogluconate alone was not evaluated. In vitro, allopirinol has been found to augment the anti: leishmanial effect of Dartiallv effective concentrations of sodium stiboglucobate (B&AN & LEE, 1983).We report here on the efficacy of a combination of allopurinol plus sodium stibogluconate in five patients with visceral leishmaniasis who were unresponsive to sodium stibogluconate alone. Patients and Methods The five patientshad visceral leishmaniasis, diagnosed by splenic aspiration (CHULAY& BRYCESON,1983), which was unresponsive to or had relapsed after treatment with sodium

stibogluconate in a dose of 20 mg Sbikg bw given once or twice daily for at least 50 days. In addition, cases1 and 2 had failed to respond to allopurihol and/or pentamidine administered over varvine durations exceeding one month. All patients were ihe; treated with allop&inol plus sodium stibogluconate. Three patients received intravenous (IV) or intramuscular (IM) injections of sodium stibogluconate at a dose of 20 mg Sb/kg bw once daily and two received this dose twice daily (Table I). Patients also received tablets of allopurinol (Zytloric’R’, Wellcome, UK) at a dose of approximately 20 mgikg bw in three divided doses daily. Both drugs were given together for between 14 and 54 days. The patients were investigated and monitored as described previously (CHULAY et al., 1983b; CHUNCE er al., 1984; BRYCESON et al., 1985b). Cure was defined as the absenceof parasites from splenic aspirate smears and cultures. Two patients (Nos. 1 and 5) were treated for concurrent pulmonary tuberculosis. All patients were followed for at least 12 months after treatment. Results

The combination of sodium stibogluconate and allopurinol was well tolerated; no clinical, biochemical or haematological toxicity was noted. All patients improved rapidly after treatment was started. The splenic aspirate smearsbecamenegative within 9 to 19 days (Table I, Fig l), and all patients had a decrease in spleen size and increase in haemoglobin and body weight after treatment. Patient 5 relapsed when treatment was stopped after 15 days becauseof a drug rash (later shown to be due to thiacetazone), but he responded when the sametreatment was resumed and continued for 30 days. After discharge from hospital, no patient relapsed during at least 12 months of follow-up. *Present Address: Deuartment of Immunoloev. Walter Reed Army Institut; of Research, Wash&ion, DC 20307-5100,

USA.

**Present Address: Hospital for Tropical Diseases, 4 St. Pancras Way, London NWi OPE. The views of the authors do not purport to reflect the uosition of the US Deoartment of the Armv or the US -Department of Defense.

:;

: g:

iz

F M I:

14

Weighta (kg) 21

icl

F

Sex

4oe 20 (52,30,0) (8,54,0) 20 (60,23,6) (-,30,0)

36' (0,14,0)' 20 (0,31,0)

Dose of sodium stibogluconate mg Sb/kd bwld (no. of days treated)

22 (0,30,0) 24 (0,54,0) 21 (0,23,0) (-,30,0)

21 (21,14,55) 21 (0,31,30)

Dose of allopurinolb mg/kg bwld (no. of days) treated)

E 2-k 1+

11

:4

19 9

:;

negative smear (days)

first

start of combined treatment

Time to

Parasite grade' at

Splenic aspirate smear

12

12

::

Duration of follow-up (months)

and allopurinol and time taken to eradicate parasites from splenic aspirate smears in five patients to sodium stibogluconate alone

a Weight at the beginning of combined treatment with sodium stibogluconate plus allopurinol. b Allopurinol was given as three divided doses pr day. ’ Grading of splenic aspirate smears: 6+ = >lO parasites/l000 microscope fields (1000 x magnification), 5+ = l-9.9 X 10’ parasites/1000 microscope fields, 4+ = l-9.9 x lo4 parasites/100 microscope fields, etc. (see CHULAY & BRYCESON, 1983). * Same as patient 9 in BRYCESON et al., 1985b. e Given as two divided doses per day. ’ Days immediately before, during, and after combined treatment. g Samepatient: allopurinol (and then sodium stibogluconate) was stopped prematurely (5A) due to a drug reaction (later shown to be caused by thiacetazone). Allopurinol and sodium stibogluconate were restarted 7 and 6 weeks later, respectively (5B).

10

z

Age (ye=@

2

1*

Case

Table I-Dosage of sodium stibogluconate with visceral leishmaniasis unresponsive

c.

N.

CHUNGE

et al.

717

65432IOI

I

-120-100

I

-80

I

I

-60 -40

I

-20

1

0

I

20

I

40

I

I

60

80

I

t

100 120

DAYSSINCESTARTING COMBINED TREATMENT Fig. 1. Parasite counts in splenic aspirate smearsin five patients before, during and after combined treatment with sodium stibogluconate and allopurinol. Seefootnote to Table I for splenic aspirate smear grading scheme.The treatment immediately preceding time 0 was: pentamidine, 5 mgikg bw three time&k plus allopurinol, 21 mgikgiday in three divided doses, for 7 weeks, followed by allopurinol alone at the samedose for 3 weeks (patient 1, 0); sodium stibogluconate, 20 mgikg bwid for 30 days, followed by pentamidine, 4 @kg bw three timesiwk for 6% weeks (patient 2, a); sodium stibogluconate, 20 mg/kg once daily for 14 days, followed by sodium stibogluconate, 20 mgikg bw twice daily for 8 days (patient 3,O); sodium stibogluconate, 20 mg/kg bw once daily for 52 days (patient 4, A); and sodium stibogluconate, 20 mgikg bw once daily for 60 days (patient 5, 0). R, indicates the point at which combined treatment was started (or resumed in patient 5).

Discussion All five patients, partially or completely unresponsive to high doses of sodium stibogluconate alone, responded to the combination of sodium stibogluconate plus allopurinol with disappearance of parasites from splenic aspirate smears within 19 days. The two drugs had either a synergistic or additive effect. The high dose of sodium stibogluconate, alone or in combination with allopurinol, did not produce serious side effects, confirming previous observations by ANABWANI et al. (1983), and CHULAY et al. (1983a, b). The mechanism of action of allopurinol in vivo may be that postulated by KAGER et al. (198 1) and NELSON et al. (1979). Leishmania parasites sequentially convert allopurinol to allopurinol ribonucleotide and the 4-aminopyrazolopyrimidine analogues of AMP, ADP and ATP, which is incorporated into parasite RNA. In vitro, allopurinol appears to have a static effect on Leishmania promastigotes (PFALLER & MARR, 1974; MARR & BERENS, 1977) and amastigotes (BERENS et al., 1980; BERMAN & WEBSTER, 1982). The mechanism by which antimonials exert anti-leishmanial activity has been incompletely investigated. Electron microscopic studies have revealed diminished definition of mitochondrial membranes in L. tropica in vitro (LANGRETH et al., 1983) and changes indicative of reduced parasite hydration and auto-digestion in L. donovani in vivo (CHULAY et al., 1985). Recently, abnormal adenosine metabolism has been demonstrated in Leishmania treated with

sodium stibogluconate in vitro (Berman et al., manuscript submitted). The ability of both allopurinol and sodium stibogluconate to modify parasite purine metabolism may be the basis for the efficacy of the combination of these two drugs in our five patients unresponsive to sodium stibogluconate alone. In view of our results, it would be useful to know if combined treatment with a pentavalent antimonial plus allopurinol in previously untreated patients would result in a more rapid cure or lower relapse rates than with the currently recommended regimen of a pentavalent antimonial alone at a dose of 20 mg Sbikg bw once daily for a minimum of 20 days (WHO 1982). Controlled clinical trials will be needed, in each endemic area, to evaluate this possibility. The dosage of allopurinol we have used is higher than that used for gout, and toxicity could present problems for mass usage. The optimum dosage for combined treatment and the duration of treatment remain to be established. Meanwhile we recommend the carefully supervised use of at least 30 days treatment with sodium stibogluconate, 20 mg Sbikg bw once daily (or possible twice daily) with allopurino16 to 8 mgikg bw three times daily, for Kenyan patients with visceral leishmaniasis unresponsive to conventional doses of antimonials. Acknowledgement To Dr. Davy Koech, Director of Clinical ResearchCentre (CRC); rhe nursing staff of the Infectious DiseasesHospital,

718

VISCERAL

LEISHMANIASIS

UNRESPONSIVE

Nairobi, Kenya; and the CRC/Walter Reed Laboratory staff. This investigation received support from UNDPWorld Bank/WHO Special Programme for Research and Training in Tropical Diseases and from grant DMAD from the US Army Medical Research and Development Command. References Anabwani, G. M., Bryceson, A. D., Nigra, J. A. & Din&i, G. (1982). Evaluation of two dosageschedulesof sodium stibogluconate (Pentostam(R))in the treatment of kalaazar in Kenya. Lancer, i, 210-213. Berens, R. L., Marr, J. J., Nelson, D. J. & LaFon, S. W. (1980). Antileishmanial effect of allopurinol and allopurinol ribonucleoside on intracellular forms of Leishmania donovani. Biochemical Pharmacology, 29, 2397-2398.

Berman, J. D. & Lee, L. S. (1983). Activity of oral drugs against Leishmania rropica in human macrophages in vitro. AmericanJournal of Tropical Medicine and Hygiene, 32, 947-951. Berman, J. D. & Webster, H. K. (1982). In vitro effects of mycophenolic acid and allopurinol against Leishmania tropica in human macrophages. Antimicrobial Agents and Chemothera~, 21, 887-891. Bryceson, A. D. M., Chulay, J. D., Ho, M., Mugambi, M., Were, J. B., Muigai? R., Chunge, C., Gachihi, G., Meme, J., Anabwam, G. & Bhatt, S. M. (1985a). Visceral leishmaniasis unresponsive to antimonial drugs. I. Clinical and immunological studies. Transactions of the Royal Society of Tropical Medicine and Hygiene, 79,

700-704. Bryceson, A. D. M., Chulay, J. D., Mugambi, M., Were, J. B., Gachihi, G., Muigai, R., Bhatt, S. M., Ho, M., Spencer, H. S., Meme, J. & Anabwani, G. (1985b). Visceral leishmaniasis unresponsive to antlmonial drugs. II. Resuonse to hieh dosage sodium stiboeluconate or prolonged treatment with pentamidine. T&actions of the _^_ Royal -_ 1 Society of Tropical Medicine and Hygiene, 79, /m-/14.

Chulay, J. D., Anzeze, E. M., Koech, D. K. & Bryceson, A. D. M. (1983). High dose sodium stibogluconate treatment of cutaneous leishmaniasis in Kenya. Transactions of the Royal Society of Tropical Medicine and Hygiene,

77, 717-721. Chulay, J. D., Bhatt, S. M., Muigai, R., Ho. M., Gachihi, G. Were, J. B. O., Chunge, C. N. & Bryceson, A. D. M. (1983b). A comparison of three dosage regimens of sodium stibogluconate in the treatment of visceral leishmaniasis in Kenya. 3ournal of Infectious Diseases, 148, 148-155.

TO ANTIMONIALS.

III.

Chulay, J. D., Fawcett, D. W. & Chunge, C. N. (1985). Electron microscopy of Leishmania donovani in splenic aspirates from patients with visceral leishmaniasisduring treatment with sodium stibogluconate. Annals of Tropical Medicine and Parasitology (in press). Chulay, J. D. & Bryceson, A. D. M. (1983). Quantitation of Lershmania donovani amastigotes in smears of splenic aspirates from patients with visceral leishmaniasis. American Journal

of Tropical Medicine

and Hygiene,

32,

475-479. Chun e, C. N., Gachihi, G., Chulay, J. D. & Spencer, H. C. (1684). Complications of kala-axar and its treatment in Kenya. East African Medical Journal, 61, 120-127. Kager, P. A., Rees, P. H., Wellde, B. T., Hockmeyer, W. T. & Lyerly, W. H. (1981). Allopurinol in the treatment of visceral leishmaniasis. Transactions of the Royal Society of Tropical Medicine and Hygiene, 75, 555-559.

Langreth, S. G., Berman, J. D., Riordan, G. P. & Lee, L. S. (1983). Fine-structural alterations in Leishmania tropica within human macrophagesexposed to antileishmania1 drugs in vitro. Journal of Prorozoology, 30, 555-561. Manson-Bahr, P. E. C. (1959). East African kala-azar with special reference to the pathology, prophylaxis and treatment. Transactions of the Roval Socierv of Trooical Medicine and Hygiene, 6, 123-l-36. * * * Marr, J. J. & Berens, R. L. (1977). Antileishmanial effect of allopurinol. II. Relationship of adenine metabolism in Leishmania speciesto the action of allopurinol. 3oumal of Infectious Diseases, 136, 724-732. Nelson, D. J., Lafon, S. W., Turtle, J. V., Miller, W. H., Miller, R. L., Krenitsky, T. A., Elion, G. B., Berens, R. L. & Marr, J. J. (1979). Allopurinol nbonucleoside as an antileishmanial agent. Biological effects, metabolism and enzymatic phosphorylation. Journal of Biological Chemiscy, 254, 22544-22549. Pfaller, M. A. & Marr, J. J. (1974). Antileishmanial effect of allopurinol. Antimicrobial Agents and Chemotherapy, 5, 469-472. .__ ..-.

Wijers, D. J. B. (1971). A ten years’ study of kala-axar in Tharaka (Meru District, Kenya). II. Relapses. East African Medical 3ourna1, 48, 551-588. World Health Organization (1982). Report of the informal meeting on the chemotherapy of visceral leishmaniasis. TDRICHEMLEISHNLIIZ. 3. Geneva: World Health

Accepted

fix

publication

18th June,

198.5.