Benign psychiatric side effects have been frequently associated with m
efloquine therapy. On the other hand, severe psychiatric disorders due
to mefloquine are rare but must be detected by physicians. Two such c
ases are reported. In the first case, excessive curative mefloquine th
erapy caused an acute psychotic state which ultimately regress without
treatment. The second report concerns a transient memory failure foll
owing prophylactic mefloquine treatment. The causative role of this co
mpound is being discussed and the importance of a differential diagnos
is of neuropsychiatric disorders from toxic or parasitic origin is und
erlined Circumstances aggravating such neuropsychiatric side effects a
nd actual recommendations concerning the prescription of mefloquine ar
e recalled.