Interactions of tricyclic antidepressant drugs with deprivation-induced fluid consumption by rats.

Six tricyclic antidepressant drugs, representing both secondary and tertiary amines and four different ring systems, were examined for their effects on deprivation-induced fluid consumption by rats in a standardized test system. All compounds reduced fluid consumption with a potency ranking of: desipramine ? amitriptyline ? doxepin ? nortriptyline ? imipramine ? protriptyline. In a similar test situation, pretreatment with PCPA markedly reduced fluid consumption at 24 hr; fluid consumption levels had not returned to normal by 15 days after dosage.