Antimonial drugs therapy

Pentavalent antimonial drugs have been the cornerstone of antileishmanial therapy for more than 70 years, in spite of their general toxicity causing a wide range of side effects [2]. Pentavalent antimonial drugs have to be administered parenterally, which is a painful procedure. Meanwhile, resistance is widespread. In India,... 

Pentamidine is an alternative to sodium stibogluconate in the treatment of visceral leishmaniasis, with similar efficacy, although resistance has been reported. The drug has been successful in some cases that have failed therapy with antimonials. The dosage is 2-4 mg/kg intramuscularly daily or every other day for up to 15 doses, and a second course may be necessary. Pentamidine has also shown success against cutaneous leishmaniasis, but it is not routinely used for this purpose. 

Allopurinol and meglumine antimoniate (Glucantime) have been evaluated in a randomized controlled trial in 150 patients with cutaneous leishmaniasis (2). They received oral allopurinol (15 mg/kg/day) for 3 weeks or intramuscular meglumine antimoniate (30 mg/kg/day, corresponding to 8 mg/kg/day of pentavalent antimony, for 2 weeks), or combined therapy. There were a few adverse effects in those who used allopurinol nausea, heartburn (n = 3), and mild increases in transaminases (n = 2). These symptoms subsided on drug withdrawal. 

Although quite a good number of compounds containing arsenic, antimony, phosphorus and other metals have been found to display a wide spectrum of activity against protozoal and helminth infections in humans and domestic animals, they find limited use in current therapy because of their high toxicity, low therapeutic indices and availability of better drugs. 

Children usually tolerate the drug well, and the dose per kilogram is the same as for adults. Patients who respond favorably show clinical improvement within 1-2 weeks of initiation of therapy. The drug may be given on alternate days or for longer intervals if unfavorable reactions occur in especially debilitated individuals. Patients infected with HIV typically relapse after successful initial therapy with either pentavalent antimonials or amphotericin B. 

In contrast, the introduction of inorganic complexes as therapies was usually based on an observed medicinal effect. Two of the earliest inorganic remedies involved the use of mercurous chloride as a diuretic, and iron complexes as mineral supplements, introduced about 500 years ago. More recently, gold complexes have been used as antibacterials, in particular for the treatment of tuberculosis at the beginning of the twentieth century. Other traditional inorganic drugs include the use of arsenic complexes, such as arsephenamaine, to treat syphihs [1] and antimony compounds for the treatment of leishmaniasis. 

Current Therapy - Parenteral antimonials include antimony potassium tartrate (tartar emetic) or the corresponding sodium salt, Stibophen (Puadin) [pentasodium antimony bis (catechol-3 5-oral drugs now in use are lucanthone (Miracil D) (XlXa) and niridazole (IX). A human... 

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