Antidepressant Medications Anti-depressant Drugs Antidepressant: phenelzine, Nardil

Antidepressant: phenelzine, Nardil

Generic Name: phenelzine
Brand Name(s): Nardil
Common Use: Antidepressant

Phenelzine is a potent monoamine oxidase (MAO) inhibitor. Monoamine oxidase is a complex enzyme system, widely distributed throughout the body. Drugs that inhibit monoamine oxidase in the laboratory are associated with a number of clinical effects. Thus, it is unknown whether MAO inhibition per se, other pharmacologic actions, or an interaction of both is responsible for the clinical effects observed.

In the treatment of depressed patients clinically characterized as "atypical", "nonendogenous" or "neurotic". These patients often have mixed anxiety and depression and phobic or hypochondriacal features. There is less conclusive evidence of its usefulness for severely depressed patients with endogenous features. Phenelzine is indicated for patients who have failed to respond to the drugs more commonly used for these conditions.

Contraindications

Known hypersensitivity to the drug, pheochromocytoma, congestive heart failure, history of liver disease or abnormal liver function tests.
The potentiation of sympathomimetic substances and related compounds by MAO inhibitors may result in hypertensive crises. Therefore, patients taking phenelzine should not be given sympathomimetic drugs (including amphetamines, cocaine, methylphenidate, dopamine, epinephrine and norepinephrine), or related compounds (including methyldopa, L-dopa, L-tryptophan, L-tyrosine and phenylalanine). Hypertensive crises during phenelzine therapy may also be caused by ingestion of foods with a high concentration of tyramine or dopamine. Therefore patients being treated with phenelzine should avoid high protein food that has undergone protein breakdown by aging, fermentation, pickling, smoking or bacterial contamination; patients should also avoid cheeses (especially aged varieties), pickled herring, beer, wine, liver, yeast extract (including brewer's yeast in large quantities), dry sausage (including Genoa salami, hard salami, pepperoni and Lebanon bologna), pods of broad beans (fava beans) and yogurt. Excessive amounts of caffeine or chocolate can also potentiate hypertensive reactions.

Phenelzine should not be used in combination with dextromethorphan or with CNS depressants such as alcohol and certain narcotics.

Patients being treated with phenelzine should also avoid any spoiled or improperly refrigerated, handled or stored protein-rich foods such as meats, fish and dairy products, inlcuding foods that may have undergone protein breakdown by aging, pickling, fermentation, or smoking to improve flavor.

OTC Medications to Avoid During Phenelzine Therapy
1. Cold and cough preparations (including those containing dextromethorphan)
2. Nasal decongestants (tablets, drops or spray)
3. Hay-fever medications
4. Sinus medications
5. Asthma inhalant medications
6. Antiappetite medicines
7. Weight-reducing preparations
8. L-tryptophan containing preparations

Also, certain prescription drugs should be avoided. Therefore, patients under the care of another physician or dentist, should inform him/her they are taking phenelzine.

Adverse Side Effects

Phenelzine is a potent inhibitor of monoamine oxidase. Because this enzyme is widely distributed throughout the body, diverse pharmacologic effects may be expected to occur. When they occur, such effects tend to be mild or moderate in severity (see below), often subside with continuing treatment, and may be minimized by adjusting dosage; rarely is it necessary to institute counteracting measures or to discontinue phenelzine.

Common side effects include:
Nervous System:
Dizziness, headache, drowsiness, sleep disturbances (including insomnia and hypersomnia), weakness and fatigue, tremors, twitching, myoclonic movements and hyperreflexia.

Gastrointestinal:
Constipation, dry mouth, gastrointestinal disturbances, elevated serum transaminases (without accompanying signs and symptoms).

Metabolic:
Weight gain.

Cardiovascular:
Postural hypotension, edema.

Genitourinary:
Sexual disturbances, i.e., anorgasmia and ejaculatory disturbances.

Less common mild to moderate side effects, some of which have been reported in a single patient or by a single physician, include:

Nervous System:
Jitteriness, palilalia, euphoria, nystagmus, paresthesias.

Genitourinary:
Urinary retention.

Metabolic:
Hypernatremia.

Dermatologic:
Skin rash, sweating.

Special Senses:
Blurred vision, glaucoma.

Although reported less frequently, and sometimes only once, additional severe side effects include:
Nervous System:
Ataxia, shock-like coma, toxic delirium, manic reaction, convulsions, acute anxiety reaction, precipitation of schizophrenia, transient respiratory and cardiovascular depression following ECT.

Gastrointestinal:
To date, fatal progressive necrotizing hepatocellular damage has been reported in a very few patients. Reversible jaundice.

Hematologic:
Leukopenia.

Metabolic:
Hypermetabolic syndrome (which may include, but is not limited to, hyperpyrexia, tachycardia, tachypnea, muscular rigidity, elevated CK levels, metabolic acidosis, hypoxia, coma, and may resemble an overdose).

Respiratory:
Edema of the glottis.

Withdrawal may be associated with nausea, vomiting and malaise.
An uncommon withdrawal syndrome following abrupt withdrawal of phenelzine has been infrequently reported. Signs and symptoms of this syndrome generally commence 24 to 72 hours after drug discontinuation and may range from vivid nightmares with agitation to frank psychosis and convulsions. This syndrome generally responds to reinstitution of low-dose phenelzine therapy followed by cautious downward titration and discontinuation.

Overdose

Signs and symptoms may be absent or minimal during the initial 12-hour period following ingestion and may develop slowly thereafter, reaching a maximum in 24 to 48 hours. Death has been reported following overdosage. Therefore, immediate hospitalization, with continuous observation and monitoring throughout this period, is essential. Signs and symptoms of overdosage may include, alone or in combination, any of the following: 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.

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.

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