A client seeks care because she feels depressed and has gained weight. To treat her atypical depression, the physician prescribes tranylcypromine sulfate (Parnate), 10 mg by mouth twice per day. When this drug is used to treat atypical depression, what is its onset of action?

1 to 2 days 3 to 5 days6 to 8 days10 to 14 days

Explanation.

Monoamine oxidase inhibitors, such as tranylcypromine, have an onset of action of approximately 3 to 5 days. A full clinical response may be delayed for 3 to 4 weeks. The therapeutic effects may continue for 1 to 2 weeks after discontinuation.