Phenelzine sulfate
Phenelzine sulfate (Nardil)
Phenelzine sulfate
( FEN-ell-zeen)
Pregnancy Category: C Nardil (Rx)

Classification: Antidepressant, monoamine oxidase inhibitor

Action/Kinetics: MAO inhibitor that prevents MAO from metabolizing biogenic amines. Antidepressant effect due to accumulation of biogenic amines in presynaptic granules, increasing the concentration of neurotransmitter released upon nerve stimulation. Slight anticholinergic, sedative, and orthostatic hypotensive effects. Onset: Few days to several months. Beneficial effects at doses of 60 mg/day may not be seen for at least 4 weeks. Clinical effects of the drug may be observed for up to 2 weeks after termination of therapy.

Uses: Depression characterized as atypical, nonendogenous, or neurotic; most often used in those clients who have mixed anxiety and depression and phobic or hypochondriacal symptoms. Not usually first-line therapy; reserve for those who have failed to respond to drugs more commonly used. Investigational: Alone or as an adjunct to treat bulimia nervosa, agoraphobia with panic attcks, globus hystericus syndrome, and chronic headache. Also for orthostatic hypotension, refractory migraine headaches, narcolepsy, obsessive-compulsive disorder, panic attacks, posttraumatic stress disorder, and social phobia.

Contraindications: Pheochromocytoma, CHF, history of liver disease, abnormal LFTs. Use with other sympathomimetic drugs due to the possibility of hypertensive crisis. Contraindicated with the use of many other drugs (see Drug Interactions). Use in children under the age of 16 years.

Special Concerns: Use with caution in combination with antihypertensive drugs, including thiazide diuretics and ß-blockers, due to the possibility of severe hypotensive effects. The safe use during pregnancy or lactation has not been determined. Use with caution in geriatric clients.

Side Effects: CNS: Dizziness, headache, drowsiness, sleep disturbances (insomnia, hypersomnia), fatigue, weakness, tremors, twitching, myoclonic movements, hyperreflexia, jitteriness, palilalia, euphoria, nystagmus, paresthesias, ataxia, shock-like coma toxic delirium, manic reaction, convulsions acute anxiety reaction, precipitation of schizophrenia. GI: Constipation, dry mouth, GI disturbances, reversible jaundice. Rarely, fatal necrotizing hepatocellular damage. CV: Postural hypotension, edema. GU: Anorgasmia, ejaculatory disturbances, urinary retention. Metabolic: Weight gain, hypernatremia, hypermetabolic syndrome. Dermatologic: Skin rash, sweating. Ophthalmic: Blurred vision, glaucoma. Miscellaneous: Leukopenia, edema of the glottis, fever associated with increased muscle tone.

Laboratory Test Alterations: Serum transaminases.

Overdose Management: Symptoms: Drowsiness, dizziness, fainting, irritability, hyperactivity, agitation, severe headache, hallucinations, trismus, opisthotonus, rigidity, convulsions, coma, rapid and irregular pulse, hypertension, hypotension, cardiovascular collapse, precordial pain, respiratory depression, respiratory failure, hyperpyrexia, diaphoresis, cold and clammy skin, death. Symptoms of overdose may be absent or minimal during the initial 12-hr period after ingestion but then slowly increase, reaching a maximum effect within 24 to 48 hr. Treatment: If detected early, induction of emesis or gastric lavage followed by a charcoal slurry. Use of IV diazepam for CNS symptoms. For hypotension and CV collapse, IV fluids and, if necessary, BP titration with an IV infusion of a dilute pressor drug. Respirations should be supported by use of supplemental oxygen and mechanical ventilation. Fluid and electrolyte balance must be maintained. Do not use phenothiazine derivatives or CNS stimulants.

Drug Interactions: Alcohol / Possibility of excitation, seizures, delirium, hyperpyrexia, circulatory collapse, coma, death Anesthetics, general / Hypotensive effect; use together with caution. Discontinue phenelzine at least 10 days before elective surgery Anticholinergic drugs, atropine / MAO inhibitor effect of anticholinergic drugs Antidepressants, tricyclic / Comcomitant use may result in excitation, sweating, tachycardia, tachypnea, hyperpyrexia, DIC, delirium, tremors, convulsions, death. At least 7-10 days should elapse between discontinuing a MAO inhibitor and initiating a new drug. Such combinations have been used together successfully Antidiabetic drugs / Potentiation of hypoglycemic response; delayed recovery from hypoglycemia Antihypertensive drugs / Exaggerated hypotensive effects Beta-adrenergic blocking drugs / Exaggerated hypotensive effects; bradycardia Bupropion / Do not use together; allow at least 10 days between discontinuing phenelzine and starting bupropion Buspirone / BP Carbamazepine / Possible hypertensive crisis, severe seizures, coma, or circulatory collapse; do not use together Dextromethorphan / Possible hyperpyrexia, abnormal muscle movement, psychosis, bizarre behavior, hypotension, coma, and death; do not use together Ephedra / See Sympathomimetic Drugs below Fluoxetine / Possibility of hyperthermia, rigidity, myoclonic movements, death. At least 10 days should elapse between discontinuing phenelzine and initiation of fluoxetine; and, at least 5 weeks should elapse between discontinuing fluoxetine and beginning phenelzine Ginseng / Risk of headache, mania, tremors Guanethidine / Guanethidine's hypotensive effect Levodopa / Possible hypertensive reactions Meperidine / Possibility of agitation, excitation, seizures, diaphoresis, delirium, hyperpyrexia, apnea, coma, death; do not use together Methyldopa / Loss of BP control or signs of central stimulation Metrizamide / Possible seizure threshold Narcotics / Use with caution with phenelzine Phenothiazines / Effect of phenothizines R/T liver breakdown; also, chance of severe extrapyramidal effects and hypertensive crisis St. John's wort / Do not use with phenelzine Scotch broom herb / Risk of hypertensive crisis due to tyramine content Succinylcholine / Succinylcholine effect R/T breakdown in the plasma by pseudocholinesterase Sulfonamides / Either sulfonamide or phenelzine toxicity Sumatriptan / Risk of sumatriptan toxicity Sympathomimetic drugs--amphetamine, cocaine, dopa, ephedrine, epinephrine, metaraminol, methyldopa, methylphenidate, norepinephrine, phenylephrine, phenylpropanolamine. Many OTC cold products, hay fever medications, and nasal decongestants contain one or more of these drugs / All peripheral, metabolic, cardiac, and central effects are potentiated for up to 2 weeks after termination of MAO inhibitor therapy. Symptoms include acute hypertensive crisis with possible intracranial hemorrhage, hyperthermia, coma, and possibly death Thiazide diuretics / Exaggerated hypotensive effects Tryptophan / Possibility of behavioral and neurologic effects, including disorientation, confusion, amnesia, delirium, agitation, hypomania, ataxia, myoclonus, hyperreflexia, shivering, ocular oscillation,and Babinski signs Tyramine-rich foods--beer, broad beans, certain cheeses (Brie, cheddar, Camembert, Stilton), Chianti wine, chicken livers, caffeine, cola beverages, figs, licorice, liver, pickled or kippered herring dry sausage (Genoa salami, hard salami, pepperoni, Lebanon bologna), tea, cream, yogurt, yeast extract, and chocolate / Possible precipitation of hypertensive crisis, including severe headache, hypertension, intracranial hemorrhage, death Yeast, Brewer's / Possible BP

How Supplied: Tablets: 15 mg.

Dosage
?Tablets Treatment of depression.
Adults, initial: 15 mg t.i.d.; then increase the dose to 60 mg/day at a fairly rapid pace (some may require 90 mg/day). Maintenance: After the maximum beneficial effect has been observed, the dose should be reduced slowly over several weeks to a range of 15 mg/day or every other day to as high as 45 mg/day or every other day. Geriatric, initial: 0.8-1 mg/kg daily in divided doses; then increase s needed to a maximum of 60 mg/day.