Treatment of antimony-unresponsive Indian visceral leishmaniasis with ultra-short courses of amphotericin-B-lipid complex

Economic evaluations addressing diagnosis and treatment strategies for neglected tropical diseases: an overview

Neglected tropical diseases (NTDs) are those affecting vulnerable people and causing additional social and economic burden. The aim of this study was to carry out a general overview of the health economic assessments involving the diagnosis and treatment of six NTDs: cutaneous leishmaniasis (CL), Chagas disease, cysticercosis, filariasis, schistosomiasis and visceral leishmaniasis (VL). The literature search was based on two of the main medical literature databases (Medline and SciELO) and identified 46 studies. Twenty-six studies (57%) addressed therapeutic strategies, while other 20 (43%) assessed diagnostic or both diagnostic and therapeutic approaches. The studies were published between 1994 and 2021, and 57% of them (26/46) were carried out in four countries. Cost-effectiveness analyses were conducted in 59% (27/46) of the studies. Economic studies of NTDs have timidly increased in recent years. Despite the improvement of analytical methods, completeness and accuracy of information, there are few new technologies applied to NTDs and public health systems. In addition, economic studies for NTDs are concentrated in a few countries. Thus, this review points out the need for investment in research, development and training of human resources dedicated to the economic analysis in health, especially on NTDs, as a strategy to reduce inequalities by optimizing the use of health resources.

Species-directed therapy for leishmaniasis in returning travellers: a comprehensive guide

Background

Leishmaniasis is increasingly reported among travellers. Leishmania species vary in sensitivity to available therapies. Fast and reliable molecular techniques have made species-directed treatment feasible. Many treatment trials have been designed poorly, thus developing evidence-based guidelines for species-directed treatment is difficult. Published guidelines on leishmaniasis in travellers do not aim to be comprehensive or do not quantify overall treatment success for available therapies. We aimed at providing comprehensive species-directed treatment guidelines.

Methodology/Principal Findings

English literature was searched using PubMed. Trials and observational studies were included if all cases were parasitologically confirmed, the Leishmania species was known, clear clinical end-points and time points for evaluation of treatment success were defined, duration of follow-up was adequate and loss to follow-up was acceptable. The proportion of successful treatment responses was pooled using mixed effects methods to estimate the efficacy of specific therapies. Final ranking of treatment options was done by an expert panel based on pooled efficacy estimates and practical considerations. 168 studies were included, with 287 treatment arms. Based on Leishmania species, symptoms and geography, 25 clinical categories were defined and therapy options ranked. In 12/25 categories, proposed treatment agreed with highest efficacy data from literature. For 5/25 categories no literature was found, and in 8/25 categories treatment advise differed from literature evidence. For uncomplicated cutaneous leishmaniasis, combination of intralesional antimony with cryotherapy is advised, except for L. guyanensis and L. braziliensis infections, for which systemic treatment is preferred. Treatment of complicated (muco)cutaneous leishmaniasis differs per species. For visceral leishmaniasis, liposomal amphotericin B is treatment of choice.

Conclusions/Significance

Our study highlights current knowledge about species-directed therapy of leishmaniasis in returning travellers and also demonstrates lack of evidence for treatment of several clinical categories. New data can easily be incorporated in the presented overview. Updates will be of use for clinical decision making and for defining further research.

Human leishmaniasis is caused by unicellular parasites that are injected into the skin by sand-flies, small, flying insects. Many different Leishmania species cause various manifestations of disease, both of the skin and internal organs. Leishmaniasis is a curable disease but clear guidelines on the best available treatment are lacking. Leishmania species differ in sensitivity to available drugs. Until recently, identification of the infecting Leishmania parasite was laborious, thus therapy could not precisely be targeted to the infecting species, in contrast to many other infectious diseases. Nowadays, Leishmania parasites can be identified relatively easily with new DNA techniques. We studied efficacy of therapies for diseases due to different Leishmania species, limited to the English literature. Efficacy was summarized and presented in an easy to read format. Because of difficulties with identification of parasite species in earlier studies, quality of evidence was often limited. Our findings are a major help for clinicians to easily find optimal treatment for specific patients. Moreover, our results demonstrate where additional research is needed to further improve treatment of leishmaniasis.

Safety and efficacy of single dose versus multiple doses of AmBisome for treatment of visceral leishmaniasis in eastern Africa: a randomised trial

Background

Anti-leishmanial drug regimens that include a single dose AmBisome® could be suitable for eastern African patients with symptomatic visceral leishmaniasis (VL) but the appropriate single dose is unknown.

Methodology

A multi-centre, open-label, non-inferiority, randomized controlled trial with an adaptive design, was conducted to compare the efficacy and safety of a single dose and multiple doses of AmBisome® for the treatment of VL in eastern Africa. The primary efficacy endpoint was definitive cure (DC) at 6 months. Symptomatic patients with parasitologically-confirmed, non-severe VL, received a single dose of AmBisome® 7.5 mg/kg body weight or multiple doses, 7 times 3 mg/kg on days 1–5, 14, and 21. If interim analyses, evaluated 30 days after the start of treatment following 40 or 80 patients, showed the single dose gave significantly poorer parasite clearance than multiple doses at the 5% significance level, the single dose was increased by 2·5 mg/kg. In a sub-set of patients, parasite clearance was measured by quantitative reverse transcriptase (qRT) PCR.

Principal Findings

The trial was terminated after the third interim analysis because of low efficacy of both regimens. Based on the intention-to-treat population, DC was 85% (95%CI 73–93%), 40% (95%CI 19–64%), and 58% (95%CI 41–73%) in patients treated with multiple doses (n = 63), and single doses of 7·5 (n = 21) or 10 mg/kg (n = 40), respectively. qRT-PCR suggested superior parasite clearance with multiple doses as early as day 3. Safety data accorded with the drug label.

Conclusions

The tested AmBisome® regimens would not be suitable for VL treatment across eastern Africa. An optimal single dose regimen was not identified.

Trials Registration

www.clinicaltrials.govNCT00832208

Visceral leishmaniasis is a potentially fatal disease which affects 0.2–0.4 million people every year, principally in South-East Asia, Latin America or Eastern Africa. Currently the safest drug in use is AmBisome®, which cures 90% of patients in India at 5 mg/kg, and is even more effective at higher doses (10 mg/kg) or in combination with miltefosine or paromomycin. These regimens have been shown to be equally cost-effective in India. However, the drug requires a cold chain for storage and reconstitution prior to injection. Although it is licensed for use in eastern Africa, in practice it is mainly used as a second-line treatment. A small study carried out in Kenya indicated that a higher dose is necessary in eastern Africa in contrast to Asia. This study aimed to determine the minimum single dose that is safe and effective for treatment of eastern African VL patients so as to be used in simplified treatment regimens. However, the tested regimens were found to be ineffective, and an optimal single dose that could potentially be used in simplified treatment regimens was not identified.

Progress in the treatment of a neglected infectious disease: visceral leishmaniasis

Visceral leishmaniasis (kala-azar) is a disseminated intracellular protozoal infection. Most cases (90%) occur in the rural regions of five countries: India, Sudan, Nepal, Bangladesh and Brazil. As with other infectious diseases embedded in high-level poverty, developing and/or delivering new treatments for visceral leishmaniasis had been painfully slow or nonexistent. However, despite persistent unresolved obstacles (e.g., drug affordability), renewed interest in visceral leishmaniasis and numerous successful treatment trials have combined to turn a therapeutic corner in the past 5 years, yielding new alternatives to conventional pentavalent antimony. Advances include the use of low-cost generic pentavalent antimony, rediscovery of amphotericin B, short-course regimens via lipid formulations of amphotericin B, retesting injectible paromyomycin and, of clear-cut importance, identifying miltefosine (Impavido, Zentaris) as the first effective oral therapy for this neglected disease.

Assessing the quality of pharmacoeconomic studies in India: a systematic review

OBJECTIVE

The aim of the study was to evaluate the quality of pharmacoeconomic studies based in India.

METHODS

A literature search was conducted using PubMed, MEDLINE, EconLit, PsycInfo and Google Scholar to identify published work on pharmacoeconomics studies based in India. Articles were included if they were original studies that evaluated pharmaceuticals, were based in India and were conducted between 1990 and 2010. Two reviewers independently reviewed the articles using a subjective 10-point quality scale in addition to the 100-point Quality of Health Economic Studies (QHES) questionnaire.

RESULTS

Twenty-nine articles published between 1998 and May 2010 were included in the review. The included articles were published in 23 different journals. Each article was written by an average of five authors. The mean subjective quality score of the 29 articles was 7.8 (standard deviation [SD] = 1.3) and the mean QHES scores for the complete pharmacoeconomic studies (n = 24) was 86 (SD = 6). The majority of authors resided in India (62%) at the time of publication and had a medical background (90%). The quality score was significantly (p ≤ 0.05) related to the country of residence of the primary author (non-India = higher) and the study design (randomized controlled trials = higher).

CONCLUSION

Although the overall quality scores were comparable to (e.g. Nigeria) or higher than (e.g. Zimbabwe) similar studies in other developing countries, key features such as an explicit study perspective and the use of sensitivity analyses were missing in about 40% of the articles. The need for economic evaluation of pharmaceuticals is imperative, especially in developing countries such as India as this helps decision makers allocate scarce resources in a justifiable manner.

Drug delivery strategies for therapy of visceral leishmaniasis

IMPORTANCE OF THE FIELD

Visceral leishmaniasis (VL) is the most overwhelming type of leishmaniasis associated with the poverty of developing countries and usually mortal if untreated. Most of the conventionally used dosage forms offer us the shortcomings of toxic side effects and emergence of drug resistance. Several efforts have been made to overcome the barriers involved in the treatment of VL. Colloidal carriers extensively represent the drug delivery systems (DDSs) for intracellular localization of antileishmanial compounds in macrophage-rich organs such as liver, spleen and bone marrow. These DDSs offer superior therapeutic efficacy over the conventional treatment in terms of site-specific drug delivery with reduced side effects. However, after 35 years of research in the field, AmBisome (Amphotericin B liposome for injection, Astellas Pharma US, Inc.) is the only DDS used against the VL.

AREAS COVERED IN THIS REVIEW

A literature search was performed (for drugs and DDSs against VL) on PubMed and through Google.

WHAT THE READER WILL GAIN

This review aims to describe the pathophysiology of VL and its current conventional treatment with special reference to DDSs designed against VL.

TAKE HOME MESSAGE

On reviewing the conventional drugs and DDSs developed against VL, it is concluded that advances in the field of targeted drug delivery can result in more efficient strategies for the therapy of VL.

Recent strategies for the chemotherapy of visceral leishmaniasis

Visceral leishmaniasis is a widespread and deadly disease. First-line drugs are antimonials, but amphotericin B and its lipid formulations B is used for treating visceral leishmaniasis that is unresponsive to antimony. New therapeutic approaches are being actively developed, including the following: use of drug carriers targeted specifically to the parasite location, thus reduce adverse effects of drug; use of immunomodulating drugs; evaluation of natural products; pharmacokinetic studies; and drug combinations. Recent clinical trials with paromomycin and miltefosine were successful and these drugs appear to be promising for the future therapy of visceral leishmaniasis. Furthermore, identification and therapeutic evaluation of specific targets in the Leishmania organism could lead to new compounds, such as antileishmanial drugs and reversal agents of drug resistance.

Treatment of visceral leishmaniasis

The Leishmania donovani complex includes L. chagasi and L. infantum, and causes visceral leishmaniasis (VL), a disseminated and potentially fatal form of leishmaniasis. The treatment options for VL are limited. Pentavalent antimonials (Sbv) are the first-line treatment options worldwide except for in Europe and Sbv-unresponsive regions of India. Amphotericin B deoxycholate is the drug of choice in India, as are its lipid formulations in Europe. However, liposomal amphotericin B (AmBisome, Gilead Sciences, Inc.) is the best antileishmanial formulation, but its prohibitive cost limits its use in endemic countries. Preferential pricing of AmBisome for patients with VL may provide hope for these underprivileged patients. Oral miltefosine and paromomycin are the other drugs that have been recently developed. Limited therapeutic options, the potential for development of resistance and serious toxicity associated with antileishmanial drugs necessitates a change in the treatment policy. A shift from monotherapy to multi-drug combinations of short courses delivered at no or affordable cost, through directly observed therapy, seems to be the only way to develop the treatment of this disease.

Amphotericin B Colloidal Dispersion for the Treatment of Indian Visceral Leishmaniasis

BACKGROUND

In Bihar, India, where visceral leishmaniasis (VL) is hyperendemic and refractory to antimony, amphotericin B is the most effective option for the treatment of VL. Lipid formulations of amphotericin B are able to circumvent the toxic effect of conventional amphotericin B, and the total dose of these formulations can be administered over a short duration. However, cost is a major constraint in the use of lipid formulations of amphotericin B. Amphotericin B colloidal dispersion (ABCD), which is a less expensive lipid formulation, has not been tested for the treatment of VL in India.

METHODS

In an open-label, randomized clinical trial, we evaluated the efficacy and safety of a 6-day course of ABCD administered to 3 different dose groups (total dose: 7.5 mg/kg [group A], 10 mg/kg [group B], and 15 mg/kg [group C]), each of which included a cohort of 135 patients.

RESULTS

Although infusion-related fever and chills occurred in 56%-68% of patients in the 3 different dose groups, 401 of 405 patients completed the treatment. All 135 patients in group A completed treatment, and the final cure rate for this group was 97%. In the group that received the highest dose of ABCD (group C), severe backache, an unusual side effect, was observed in 8 patients (5.92%). Serious adverse effects led to the withdrawal of 2 patients (1.48%) each from group B and group C.

CONCLUSIONS

Although the cost of ABCD is prohibitive, the high level of efficacy associated with short-term treatment with low-dose ABCD provides another alternative for the treatment of VL, especially in regions where VL is antimony refractory.

Treatment options for visceral leishmaniasis: a systematic review of clinical studies done in India, 1980-2004

The state of Bihar in India carries the largest share of the world's burden of antimony-resistant visceral leishmaniasis. We analysed clinical studies done in Bihar with different treatments between 1980 and 2004. Overall, 53 studies were included (all but one published), of which 15 were comparative (randomised, quasi-randomised, or non-randomised), 23 dose-finding, and 15 non-comparative. Data from comparative studies were pooled when appropriate for meta-analysis. Overall, these studies enrolled 7263 patients in 123 treatment arms. Adequacy of methods used to do the studies and report on them varied. Unresponsiveness to antimony has developed steadily in the past to such an extent that antimony must now be replaced, despite attempts to stop its progression by increasing dose and duration of therapy. The classic second-line treatments are unsuited: pentamidine is toxic and its efficacy has also declined, and amphotericin B deoxycholate is effective but requires hospitalisation for long periods and toxicity is common. Liposomal amphotericin B is very effective and safe but currently unaffordable because of its high price. Miltefosine-the first oral drug for visceral leishmaniasis-is now registered and marketed in India and is effective, but should be used under supervision to prevent misuse. Paromomycin (or aminosidine) is effective and safe, and although not yet available, a regulatory submission is due soon. To preserve the limited armamentarium of drugs to treat visceral leishmaniasis, drugs should not be deployed unprotected; combinations can make drugs last longer, improve treatment, and reduce costs to households and health systems. India, Bangladesh, and Nepal agreed recently to undertake measures towards the elimination of visceral leishmaniasis. The lessons learnt in Bihar could help inform policy decisions both regionally and elsewhere.

Efficacy of picroliv in combination with miltefosine, an orally effective antileishmanial drug against experimental visceral leishmaniasis

Visceral leishmaniasis (VL) or kala-azar continues to persist as one of the major public health problems in many tropical countries. However, no effective treatment for radical cure of the disease is yet available. Miltefosine, an alkyl phospholipid compound, is the first orally effective drug, which has shown 98% cure rate of VL patients during phase III clinical trial in India. Since this drug requires long course of treatment and has long half-life, there are fairly good chances of emergence of resistance. Furthermore, this drug has produced severe side-effects in some of the cases. We therefore examined the possibility of minimizing these effects by applying miltefosine in lower doses in combination with picrloviv, an immunomodulator against Leishmania donovani in hamsters (Mesocricetus auratus). The picroliv per se showed no antileishmanaial potential. However, when given with suboptimal dose of miltefosine, it enhanced efficacy of the latter from 45 to 86% on day 7 post treatment and from 32 to 64% on day 28 post treatment. Interestingly, the efficacy of this combination was as good as the curative dose of miltefosine alone. Thus, this combination appears to offer a fruitful strategy for treatment of VL.

Amphotericin B lipid complex: in visceral leishmaniasis

Amphotericin B lipid complex is a lipid formulation of amphotericin B, an antifungal drug with activity against Leishmania spp. Amphotericin B lipid complex appears to enhance uptake of amphotericin B by infected macrophages in patients with visceral leishmaniasis (VL). In randomised, open-label, dose-ranging studies, short-course treatment with once-daily amphotericin B lipid complex (5-15 mg/kg total cumulative dose over 5 days), administered by intravenous infusion, produced high rates of apparent (day 19) [93-100%] and definitive (6 months) [79-100%] cures in Indian patients with antimonial-resistant VL. Amphotericin B lipid complex appeared to be as effective as liposomal amphotericin B or the conventional deoxycholate formulation in a randomised, open-label study conducted in India in a mixed population of patients with previously untreated or antimonial-resistant VL. In patients with HIV infection and VL, amphotericin B lipid complex 3 mg/kg/day for 5 or 10 days appeared to be as effective as meglumine antimonate 20 mg/kg/day for 28 days in a small randomised pilot study in southern Europe. Amphotericin B lipid complex was generally well tolerated in patients with VL. Infusion-related reactions were the most common adverse events associated with amphotericin B lipid complex.

Anti-leishmanial activity of a new formulation of amphotericin B

The effectiveness of albumin microspheres loaded with amphotericin B was tested in an in vivo model of visceral leishmaniasis using the golden hamster. Free and encapsulated amphotericin B was tested at the dose of 1 mg/kg given by the intracardiac route on days 25, 26 and 27 post-infection (p.i.) to treat animals previously infected with 10(7) stationary promastigotes by the intracardiac route. Encapsulated amphotericin was highly effective against infection causing a reduction of 88.8% and 87.2% in the early stage of infection (day 32 p.i.) and of 66.7% and 54% in a later stage of infection (day 135 p.i.) in liver and spleen parasite load respectively, compared with untreated animals, whereas free amphotericin was inactive. Lymphocyte proliferation was restored together with an increase in CD4(+) subsets in animals treated with encapsulated amphotericin B, but not in those treated with the non-encapsulated compound. Antibody responses did not increase after treatment with encapsulated amphotericin B with antibody levels remaining at base levels for most animals in contrast to those of untreated or treated with free amphotericin, where in most animals the antibody levels sharply increased. This new formulation could be a more economical alternative to liposomes for the treatment of visceral leishmaniasis with amphotericin B.

Hexadecylphosphocholine interaction with lipid monolayers

The phospholipid analogue miltefosine or hexadecylphosphocholine (HePC) is a drug of high interest in the treatment for fatal visceral leishmaniasis (VL) due to Leishmania donovani particularly because of its activity by oral route. In this study, the interaction of HePC with a monolayer of beta-palmitoyl-gamma-oleyl-phosphatidylcholine (POPC) as membrane model or sterol (ergosterol or cholesterol) was investigated. At a constant pressure of 25 mN/m, the adsorption kinetics of HePC into the monolayers showed that HePC molecules are inserted into the monolayer of lipids as monomers until the critical micellar concentration (CMC). At HePC concentrations superior to the CMC, the micelles of HePC are deployed at the interface as groups of monomers into the POPC or sterol monolayer. The study of mixture of HePC/(POPC or sterol), spread at the air-water interface, shows that a simple miscibility between HePC and POPC is observed, whereas a high condensation appears between HePC and sterols showing a high affinity between HePC and sterols. In addition, HePC does not act as detergent disturbing membrane integrity.

Toxicity and antileishmanial activity of a new stable lipid suspension of amphotericin B

The aim of the present study was to evaluate the toxicity and the activity of a new lipid complex formulation of amphotericin B (AMB) (LC-AMB; dimyristoyl phosphatidylcholine, dimyristoyl phosphatidylglycerol, and AMB) that can be produced by a simple process. Like other lipid formulations, this new complex reduced both the hemolytic activity of AMB (the concentration causing 50% hemolysis of human erythrocytes, >100 microg/ml) and its toxicity toward murine peritoneal macrophages (50% inhibitory concentration, >100 microg/ml at 24 h). The in vivo toxicity of the new formulation (50% lethal dose, >200 mg/kg of body weight for CD1 mice) was similar to those of other commercial lipid formulations of AMB. The complex was the most effective formulation against the DD8 strain of Leishmania donovani. It was unable to reverse the resistance of an AMB-resistant L. donovani strain. In vivo LC-AMB was less efficient than AmBisome against L. donovani.

Single-dose liposomal amphotericin B in the treatment of visceral leishmaniasis in India: a multicenter study

Widespread antimony resistance renders conventional amphotericin B the only option for the treatment of visceral leishmaniasis (VL) in North Bihar, India. Because of its excellent safety profile, a large dose (7.5 mg/kg) of liposomal amphotericin B (L-AmB) was given to each of 203 patients with VL at 4 treatment centers, and the patients were discharged the next day. At initial clinical and parasitological follow-up, performed on day 30 after treatment, evidence of a cure was seen in 195 (96%) of 203 patients (95% CI, 92-98); 4 patients experienced treatment failure. Two patients were lost to follow-up, 2 died (one due to progressive disease and another, 5 months after treatment, due to an unrelated illness), and 12 experienced relapses during follow-up. Thus, 183 patients (90%; 95% CI, 85-94) had obtained final cure 6 months after treatment. Very few adverse events (fever with rigor, in 9.8% of patients) were seen. Single-dose L-AmB (7.5 mg/kg) treatment is safe and effective, and it may be used for the mass treatment of VL in India.

Dendritic cell-based immunotherapy combined with antimony-based chemotherapy cures established murine visceral leishmaniasis

Dendritic cells (DCs) have been proposed to play a critical role as adjuvants in vaccination and immunotherapy. In this study we evaluated the combined effect of soluble Leishmania donovani Ag (SLDA)-pulsed syngeneic bone marrow-derived DC-based immunotherapy and antimony-based chemotherapy for the treatment of established murine visceral leishmaniasis. Three weekly injections of SLDA-pulsed DCs into L. donovani-infected mice reduced liver and splenic parasite burden significantly, but could not clear parasite load from these organs completely. Strikingly, the conventional antileishmanial chemotherapy (sodium antimony gluconate) along with injections of SLDA-pulsed DCs resulted in complete clearance of parasites from both these organs. Repetitive in vitro stimulation of splenocytes from uninfected or L. donovani-infected mice with SLDA-pulsed DCs led to the emergence of CD4(+) T cells with characteristics of Th1 cells. Our data indicate that DC-based immunotherapy enhances the in vivo antileishmanial potential of antimony or vice versa.

Two doses of a lipid formulation of amphotericin B for the treatment of Mediterranean visceral leishmaniasis

To evaluate the efficacy of a short course of a lipid formulation of amphotericin B (L-AmB) for the treatment of Mediterranean visceral leishmaniasis (VL), an open prospective study was conducted. Forty-one children with parasitologically confirmed leishmaniasis received L-AmB, 10 mg/kg daily for 2 days. The comparison groups were 30 children who, in a previous study, were treated with L-AmB, 4 mg/kg daily for 5 days, and 52 children who were treated with meglumine antimoniate. At 6 months after completion of treatment, overall treatment success was noted for 40 of 41 children treated with 2 doses of L-AmB, 27 of 30 children treated with 5 doses of L-AmB, and 47 of 52 children treated with meglumine antimoniate. Abatement of fever, reduction in spleen size, and correction of laboratory parameters occurred more quickly among the children who received 2 doses of L-AmB than among the comparison groups, and the total estimated cost of the 2-dose regimen was also lower than that of the other regimens. Two doses of L-AmB, 10 mg/kg each, is cost-effective therapy for Mediterranean VL in children.

Anilino-(2-bromophenyl) acetonitrile: a promising orally effective antileishmanial agent

Visceral leishmaniasis (VL) or kala-azar is a worldwide disseminated intracellular infection caused by the hemoflagellate protozoan parasites Leishmania donovani. Chemotherapeutic scenario presents a deplorable picture and demands an urgent search for a new and safe anti-VL drugs, preferably active by oral route. In search of new antileishmanial agents, a total of 16 compounds belonging to the anilino-(substituted phenyl)-acetonitrile class were tested in vitro in promastigote/macrophase-amastigote systems and in vivo in L. donvoani/hamster model for their antileishmanial activity. Compound 3, anilino-(2-bromophenyl)-acetonitrile, exhibited most promising activity both in vitro at a concentration of 100 microg/ml (82.33 and 94.36% in promastigote and macrophase-amastigote systems, respectively) and in vivo at a dose of 50 mg/kg for 5 days (82.11 and 80% by i.p. and p.o. routes, respectively), hence this compound was investigated in detail. To maximize its bioavailability, dissolution profile, absorption, the compound was also tested in vivo as its soluble form. But no enhancement in activity was observed. From the results of different parameters for example ED(50) and LD(50) etc. compound 3 appears to be a potent orally effective compound which could further be investigated to establish its potential as a candidate molecule of antileishmanial therapy.

Combination therapy with indolylquinoline derivative and sodium antimony gluconate cures established visceral leishmaniasis in hamsters

2-(2"-Dichloroacetamidobenzyl)-3-(3'-indolylquinoline), designated indolylquinoline derivative A, reduced the splenic and the liver parasite burdens by >93.0% in Leishmania donovani-infected hamsters, whereas sodium antimony gluconate (SAG) reduced the burdens approximately 80.0%. Complete clearance of parasitemia from the livers and spleens was noticed when infected animals received indolylquinoline derivative A plus SAG, suggesting that indolylquinoline derivative A has potential as a new agent for sole or conjunctive therapy for leishmaniasis.

Treatment of Indian visceral leishmaniasis with single or daily infusions of low dose liposomal amphotericin B: randomised trial

OBJECTIVE

To test short course, low dose liposomal amphotericin B as single or daily infusion treatment in Indian visceral leishmaniasis (kala-azar).

DESIGN

Randomised, open label study.

SETTING

Inpatient unit for leishmaniasis in Bihar, India.

PARTICIPANTS

91 adults and children with splenic aspirate positive for infection.

INTERVENTIONS

Total dose of 5 mg/kg of liposomal amphotericin B given as a single infusion (n=46) or as once daily infusions of 1 mg/kg for five days (n=45).

MAIN OUTCOME MEASURES

Clinical and parasitological cure assessed 14 days after treatment and long term definitive cure (healthy, no relapse) at six months.

RESULTS

All but one person in each group had an initial apparent cure. During six months of follow up, three patients in the single dose group and two in the five dose group relapsed. Complete response (definitive cure) was therefore achieved in 84 of 91 subjects (92%): 42 of 46 patients in the single dose group (91%, 95% confidence interval 79% to 98%) and 42 of 45 in the five dose group (93%, 82% to 99%). Response rates in the two groups were not significantly different.

CONCLUSION

Low dose liposomal amphotericin B (5 mg/kg), given either as a five day course or as a single infusion, seems to be effective for visceral leishmaniasis and warrants further testing.

Treatment of visceral leishmaniasis (kala-azar): a decade of progress and future approaches

In 1990, there was essentially one treatment regimen in use for visceral leishmaniasis (kala-azar) around the world: 20 to 28 days of daily injections of pentavalent antimony (Sb). During the past 10 years, however, new agents have been tested alone or in combination, in more than 50 studies carried out worldwide. This renewed clinical effort was spurred by a variety of factors, including the emergence of large-scale Sb unresponsiveness in India, where up to one-half of the world's cases of kala-azar now are found. As this new decade opens, the success of this clinical research effort is tangible: three additional, highly effective parenteral regimens now are available (amphotericin B, lipid formulations of amphotericin B, aminosidine), and an active oral agent, a long sought after objective in kala-azar, has been identified (miltefosine). This report reviews the evolution of treatment of visceral leishmaniasis, considers the interaction of the immune response and chemotherapy, highlights therapeutic successes and failures, examines advantages and disadvantages of current treatments, and looks at future therapeutic approaches to the management of this disseminated intracellular protozoal infection.

Failure of pentavalent antimony in visceral leishmaniasis in India: report from the center of the Indian epidemic

In India, 320 patients with visceral leishmaniasis (209 in the state of Bihar and 11 in the neighboring state of Uttar Pradesh) received identical pentavalent antimony (Sb) treatment. Sb induced long-term cure in 35% (95% confidence interval [CI], 28%-42%) of those in Bihar versus 86% (95% CI, 79%-93%) of those in Uttar Pradesh. In Bihar, the center of the Indian epidemic, traditional Sb treatment should be abandoned.

Short-course, cost-effective treatment with amphotericin B-fat emulsion cures visceral leishmaniasis

Although short-course therapy with new lipid formulations of amphotericin B represents an advance over lengthy traditional treatments in visceral leishmaniasis (kala-azar), high cost has rendered these agents largely irrelevant in developing countries where the disease is endemic. Therefore, we tested standard amphotericin B deoxycholate mixed with a commercial fat emulsion as short-course treatment for Indian visceral leishmaniasis in Bihar in 1997/98. Seventy children and adults with splenic aspirate-documented infection, 23 of whom had failed prior antimony (Sb) therapy, received 5 alternate-day infusions of 2 mg/kg. Apparent cure, which required a parasite-free splenic aspirate smear, was assessed 20 days after treatment (day 30); definitive cure was determined at 6 months. Other than anticipated infusion-related fever and/or chills, treatment was safe and well tolerated. One patient required dose modification because of mild, reversible renal insufficiency. Sixty-nine patients (98.6%, CI 92.3-100%) had apparent cures; during follow-up, there were 4 treatment failures (relapses, 3; unrelated death, 1), yielding definitive cures in 65 of 70 patients (92.9%, CI 84.1-97.6%). Including retreatment costs for patients in Bihar (who now often fail initial Sb therapy), the final per patient cost of the tested regimen (US $260) was 59% and 43% less than treatment with Sb or conventional amphotericin B alone, respectively. Short-course treatment with amphotericin B-fat emulsion is active, cost-effective treatment for patients with visceral leishmaniasis including those with Sb-unresponsive infection.

Leishmaniasis at the End of the Millennium

The term leishmaniasis refers to the spectrum of disease caused by Leishmania species. The clinical manifestations of leishmaniasis depend on complex interactions between the virulence characteristics of the infecting Leishmania species and the genetically determined cell-mediated immune responses of its mammalian host. Leishmaniasis comprises three major syndromes: cutaneous, mucosal, and visceral. Variations exist within each syndrome.