Mefloquine is being used as malaria prevention by Plasmodium Falciparum in chloroquine-resistant zones. We describe a woman who developed a manic episode with psychotic symptoms during mefloquine treatment.

The case describes a 26-year-old Spanish woman who had been working in Mali for the last six months and had started antimalarial prevention with mefloquine. In Mali, the clinical picture had a sudden debut and she related: excessive happiness, incapacity to sleep, and megalomania (she believed to have special powers and to be the mother of all the children). She was admitted in a hospital in Mali for seven days and received treatment with haloperidol and chlorpromazine. Then, she was repatriated to Spain without treatment and she continued suffering the same symptoms. After 15 days, she went to our hospital and she was admitted. Treatment started with risperidone (up to 6 mg/day) and clonazepam (up to 1.5 mg/day). At admission Young Mania Rating Scale (YMRS) was 25 points. Physical examination and complementary tests were normal, and was orientated as a manic episode with psychotic symptoms secondary to mefloquine. She had a quick symptomatic improvement (after 7 days of treatment YMRS was 5 points) and was discharged after 15 days.

Mefloquine more frequent adverse neuropsychiatric effects are: dizziness, vivid dreams and insomnia. Others are confusion, and auditory hallucinations. Side effects are dose dependent. Psychotic symptoms are frequently auto-limited when mefloquine is suppressed but treatment with atypical antipsychotics is often needed. MDR1/ABCB1 polymorphisms may play a role in neuropsychiatric side effects.