Pyrimethamine-sulfadoxine adverse effects

The chemotherapeutic response of Plasmodium berghei to various combinations of mefloquine with other drugs (sulfadoxine + pyrimethamine, primaquine, floxacrine) have shown that the desired effects are purely additive (SEDA-13, 809), so the adverse effects too are probably only those of the individual compounds. Adverse reactions occurred in 46% of 400 patients treated with Fanimef (mefloquine + pyrimethamine + sulfadoxine) (SEDA-12, 693). Of note were dizziness (29%), nausea (9.5%), vomiting (7.3%), weakness/lassitude (5.8%), abdominal discomfort or pain (5.5%), diarrhea (3.8%), pruritus (3.0%), insomnia (2.0%), and headache (2.0%). 

Pyrimethamine (25 mg), sulfadoxine (500 mg), and mefloquine (250 mg) are available in the combination formulation known as Fansimef. The adverse effects characteristic of aU three components can be expected. 

The hematological adverse effects of the combination of pyrimethamine plus sulfadoxine are largely those known from pyrimethamine, that is leukopenia, agranulocytosis, thrombocytopenia, and pancytopenia, but the literature gives the impression that when using this combination these effects are more marked, with lower cell counts (5). 

Intermittent iron supplementation with pyrimethamine + sulfadoxine has been investigated in 328 anemic but symptom-free Kenyan children, who were randomly given either iron (ferrous fumarate suspension 6.25 g/1 twice a week) or placebo and pyrimethamine + sulfadoxine (25 mg and 1.25 mg/kg once every 4 weeks) or placebo (82 in each group) (6). After 12 weeks, those who took iron and pyrimethamine + sulfadoxine, iron alone, or pyrimethamine + sulfadoxine alone had higher hemoglobin concentrations than those who took the double placebo. No adverse effects were reported. 

Observational studies During a surveillance period of 2 years, 1552 patients with uncomplicated P. falciparum malaria who had received sulfadoxine 4- pyrimethamine with artesunate on the Northern coast of Peru were followed up 8.8% reported at least one adverse effect, the most common being vomiting, nausea, headache, abdominal pain, dizziness, and fever there were no severe adverse effects [13 ]. 

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