Pupil studies in depressed patients: an investigation of the mechanism of action of desipramine.
Six depressed patients were treated routinely with desipramine, a relatively selective noradrenergic uptake blocking drug. After 0, 1 and 3 weeks' treatment, pupillary responses to tyramine, phenylephrine and pilocarpine were measured using a photographic techniques. Both 1 and 3 weeks' treatment significantly inhibited tyramine and phenylephrine-induced mydriasis, but did not inhibit pilocarpine-induced miosis; in fact the longer treatment enhanced miosis due to pilocarpine. Resting pupil size was significantly increased after 1 and 3 weeks' treatment. The findings can be explained by the known ability of desipramine to block noradrenaline uptake and alpha adrenoceptors: they provide no evidence of muscarinic receptor blockade or of a slowly developing adaptation at alpha adrenoceptors.
D000328:Adult; D000368:Aged; D003866:Depressive Disorder / Q000503:physiopathology*; D003891:Desipramine / Q000494:pharmacology*; D004357:Drug Synergism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010656:Phenylephrine / Q000037:antagonists & inhibitors; D010862:Pilocarpine / Q000494:pharmacology; D011680:Pupil / Q000187:drug effects*; D014439:Tyramine / Q000037:antagonists & inhibitors
D010862:Pilocarpine; D010656:Phenylephrine; D003891:Desipramine; D014439:Tyramine