TCAs have a similar spectrum of action as MAOIs but are less effective. They also have fewer serious side effects than MAOIs but more than SSRIs. Antiadrenergic Agents appear to reduce arousal, reexperiencing, and possibly dissociative symptoms but have not been tested adequately in clinical trials. They are generally safe, although blood pressure and pulse rate must be monitored routinely. Special caution must be observed when prescribing these agents for patients with low blood pressure or who are receiving anti-hypertensive medications.
Tolerance sometimes develops to clonidine, which is less likely with guanfacine.
Propranolol may sometimes produce depressive symptoms or psychomotor slowing. They have been tested in several open clinical trials but not in any randomized clinical trials. Both drugs have proven efficacy in bipolar affective disorders. Both drugs may cause significant side effects, especially carbamazepine. These are both effective anxiolytics and antipanic agents.