RESUMO
Benign psychiatric side effects have been frequently associated with mefloquine therapy. On the other hand, severe psychiatric disorders due to mefloquine are rare but must be detected by physicians. Two such cases are reported. In the first case, excessive curative mefloquine therapy caused an acute psychotic state which ultimately regress without treatment. The second report concerns a transient memory failure following prophylactic mefloquine treatment. The causative role of this compound is being discussed and the importance of a differential diagnosis of neuropsychiatric disorders from toxic or parasitic origin is underlined. Circumstances aggravating such neuropsychiatric side effects and actual recommendations concerning the prescription of mefloquine are recalled.