Sodium Stibogluconate Antiprotozoal Drugs

SODIUM STIBOGLUCONATE

Pentavalent antimonials, including sodium stibogluconate (pen-tostam; Figure 52–3) and meglumine antimoniate, are generally considered first-line agents for cutaneous and visceral leishmania-sis except in parts of India, where the efficacy of these drugs has diminished greatly. The drugs are rapidly absorbed and distributed after intravenous (preferred) or intramuscular administration and eliminated in two phases, with short initial (about 2-hour) half-life and much longer terminal (> 24-hour) half-life. Treatment is given once daily at a dosage of 20 mg/kg/d intravenously or intra-muscularly for 20 days in cutaneous leishmaniasis and 28 days in visceral and mucocutaneous disease.

The mechanism of action of the antimonials is unknown. Their efficacy against different species may vary, possibly based on local drug resistance patterns. Cure rates are generally quite good, but resistance to sodium stibogluconate is increasing in some endemic areas, notably in India where other agents (eg, amphot-ericin or miltefosine) are generally recommended.

Few adverse effects occur initially, but the toxicity of stibogluconate increases over the course of therapy. Most common are gastrointestinal symptoms, fever, headache, myalgias, arthralgias, and rash. Intramuscular injections can be very painful and lead to sterile abscesses. Electrocardiographic changes may occur, most commonly T-wave changes and QT prolongation. These changes are generally reversible, but continued therapy may lead to dangerous arrhythmias. Thus, the electrocardiogram should be monitored during therapy. Hemolytic anemia and serious liver, renal, and cardiac effects are rare.