Snapshot A patient presents to your office for follow-up for treatment of depression. He just emigrated from Chile where he was treated by a psychiatrist for his depression. A few weeks ago, he attended a holiday party with his family. He noted that on several occasions even prior to the holiday party, he would get a pounding headache and experienced flushing when he consumed wine or cheese and stated that his never occurred prior to his treatment of depression. Upon reviewing his medications the physician decides to start the patient on a more appropriate first-line treatment for his depression - an SSRI. introduction Drugs non-selective inhibitors phenelzine tranylcypromine isocarboxazid MAO-B selective inhibitor selegiline rasagiline used in Parkinson's treatment to increase dopamine levels Mechanism ↓ MAO activity results in ↓ amine degradation and ↑ in levels of amine neurotransmitters (mainly NE and 5-HT) Clinical use atypical depression that is refractory to other medications anxiety hypochondriasis Toxicity hypertensive crisis tyramine ingestion tyramine found in many foods, such as wine and cheese MAO normally degrades tyramine, but when inhibited is fully absorbed and displaces catecholamines other sympathomimetics CNS stimulation contraindicated with other 5-HT altering drugs (SSRIs and SNRIs) or meperidine to prevent serotonin syndrome myoclonus, hyperthermia, flushing, tachycardia, delirium treat with serotonin antagonist (cyproheptadine) and stop offending agent