oxamniquina

Oxamniquine is an antiparasitic medication used to treat intestinal schistosomiasis caused by Schistosoma mansoni. It was developed in the 1970s and for several decades was a primary treatment in some endemic regions, particularly where praziquantel was less available. Over time its use has declined as praziquantel became the preferred, broad-spectrum therapy.

Mechanism of action and pharmacology: Oxamniquine is considered a prodrug that requires activation by the parasite’s sulfotransferase enzyme. The resulting reactive metabolite is thought to damage the worm’s tegument and internal tissues, leading to parasite death. The exact molecular targets are not fully understood. It is administered orally in single-dose regimens and is metabolized by the liver with inactive metabolites excreted in urine.

Spectrum and efficacy: The drug is primarily active against Schistosoma mansoni and shows limited or variable activity against other Schistosoma species. Its efficacy is generally lower and less consistent than that of praziquantel, which has contributed to its reduced role in current schistosomiasis control programs. In some settings it remains an option when praziquantel is unavailable or when local guidelines indicate selective use.

Safety and contraindications: Common adverse effects include nausea, abdominal discomfort, dizziness, and headaches. Severe hypersensitivity is rare. Safety in pregnancy has not been established, so use is typically avoided in pregnant individuals unless clearly indicated. Caution is advised in hepatic impairment and in patients with a history of drug allergies.

Current status: Due to resistance concerns and the widespread adoption of praziquantel, oxamniquine is no longer a first-line treatment in most programs and is less widely available, though it may still be used in certain regions or research contexts.