• Metabolism: Hepatic. Acetylation of phenelzine appears to be a minor metabolic pathway. Beta-phenylethylamine is a metabolite of phenelzine, and there is indirect evidence that phenelzine may also be ring-hydroxylated and N-methylated. Route of Elimination: NARDIL® is extensively metabolized, primarily by oxidation via monoamine oxidase. Half Life: 1.2-11.6 hours following single dose administration. Multiple-dose pharmacokinetics have not been studied.
• Uses/Sources: For the treatment of major depressive disorder. Has also been used with some success in the management of bulimia nervosa.
• Symptoms: Symptoms of overdose include drowsiness, dizziness, faintness, irritability, hyperactivity, agitation, severe headache, hallucinations, trismus, opisthotonos, convulsions and coma, rapid and irregular pulse, hypertension, hypotension and vascular collapse, precordial pain, respiratory depression and failure, hyperpyrexia, diaphoresis, and cool, clammy skin.
• Treatment: Intensive symptomatic and supportive treatment may be required. Induction of emesis or gastric lavage with instillation of charcoal slurry may be helpful in early poisoning, provided the airway has been protected against aspiration. Signs and symptoms of central nervous system stimulation, including convulsions, should be treated with diazepam, given slowly intravenously. Phenothiazine derivatives and central nervous system stimulants should be avoided. Hypotension and vascular collapse should be treated with intravenous fluids and, if necessary, blood pressure titration with an intravenous infusion of dilute pressor agent. It should be noted that adrenergic agents may produce a markedly increased pressor response. Respiration should be supported by appropriate measures, including management of the airway, use of supplemental oxygen, and mechanical ventilatory assistance, as required. Body temperature should be monitored closely. Intensive management of hyperpyrexia may be required. Maintenance of fluid and electrolyte balance is essential. (L1712)
• Route of Exposure: Readily absorbed after oral administration.

Although the exact mechanism of action has not been determined, it appears that the irreversible, nonselective inhibition of MAO by phenelzine relieves depressive symptoms by causing an increase in the levels of serotonin, norepinephrine, and dopamine in the neuron.