Behavioural effects of co-administration of delta9-tetrahydrocannabinol with fluoxetine in rats

Previous studies have suggested panic induced by cannabinoids may be potentiated by concurrently using selective serotonin reuptake inhibitors. We therefore tested for panic and anxiety-related behaviour in rats coadministered with the selective serotonin reuptake inhibitor fluoxetine hydrochloride and the CB1 agonist delta9-tetrahydrocannabinol. Although each drug alone elicited behaviours consistent with previous studies, we did not find that coadministration of these drugs potentiated or reduced the effects of either drug alone. Specifically, fluoxetine treatment did not cause any increase in freezing behaviour, decrease in social interaction or exploration in an adverse environment, change preference for outer or inner zones, or modulate rearing behaviour in rats receiving delta9-tetrahydrocannabinol.