Malaria in pregnancy: efficacy of a low dose of mefloquine in an area holoendemic for multi-drug resistant Plasmodium falciparum.

Thirty-three pregnant women with pure P. falciparum parasitaemias (> or = 10(3) parasites/microliters blood), were each treated with a single, oral dose (12.5 mg/kg body weight) of mefloquine base (MQ), at Ahmadu Bello University Teaching Hospital, Zaria urban area, Nigeria. All 33 women were aparasitaemic by day 6 post-treatment and none became parasitaemic during the remaining 21 days of observation. Minimal side-effects were reported by the patients. The mean (S.D.) fever- and parasite-clearance times were 48 (17) and 50 (26) h, respectively. In standard microtests in vitro, schizont maturation was inhibited with MQ at 16 pmol/well (3.2 pmol/microliters). These findings indicate that, at least in the study area, semi-immune, pregnant women have high tolerability to relatively low doses of MQ and that such doses are fully effective against the local P. falciparum isolates.