title: Imipramine in panic disorder. 2. Effects on α2-adrenoceptor function.
abstract: Untreated patients with panic disorder have been shown to have altered α(2)-adrenoceptor sensitivity, as assessed by clonidine challenge testing. We investigated clonidine-induced biochemical, physiological, hor monal and psychological responses in six panic patients, before and after treatment with imipramine. Comparison of the clonidine-induced fall in plasma MHPG pre- and post-treatment showed it to be sig nificantly reduced after imipramine. Significantly smaller clonidine-induced falls in diastolic blood pressure and heart rate occurred after imipramine treatment. However, growth hormone and sedation responses were not altered. These data suggest that reduced sensitivity of some central α(2)-adrenoceptors occurs during treatment of panic disorder with imipramine. However, these changes do not fully explain the therapeutic actions of antidepressants in this condition.
authors.affiliation: University Department of Psychiatry, Warneford Hospital, Oxford, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Nutt
authors.forename: P
authors.initials: P
authors.lastname: Glue