Behavioral interactions of fluoxetine and other 5-hydroxytryptamine uptake inhibitors with ethanol in tests of anxiety, locomotion and exploration.

The 5HT uptake inhibitor fluoxetine had no effect on motor activity or directed exploration (head-dipping) in a holeboard test or in an elevated plusmaze test of anxiety. Fluoxetine (20 mg/kg) attenuated the anxiolytic effect of a 2.4 g/kg dose of ethanol in the plusmaze but failed to alter ethanol's effects on exploratory head-dipping or locomotion. This interaction did not seem directly related to fluoxetine's 5HT uptake inhibiting properties because it was not observed with other 5HT uptake inhibitors (fluvoxamine and citalopram). Desipramine, which predominantly inhibits noradrenaline uptake, also failed to show effects similar to those of fluoxetine.