PHENELZINE SULFATE — phenelzine sulfate tablet
Novel Laboratories, Inc.
Suicidality and Antidepressant Drugs
Antidepressants increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults in short-term studies of major depressive disorder (MDD) and other psychiatric disorders. Anyone considering the use of Phenelzine Sulfate Tablets or any other antidepressant in a child, adolescent, or young adult must balance this risk with the clinical need. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24; there was a reduction in risk with antidepressants compared to placebo in adults aged 65 and older. Depression and certain other psychiatric disorders are themselves associated with increases in the risk of suicide. Patients of all ages who are started on antidepressant therapy should be monitored appropriately and observed closely for clinical worsening, suicidality, or unusual changes in behavior. Families and caregivers should be advised of the need for close observation and communication with the prescriber. Phenelzine Sulfate Tablets is not approved for use in pediatric patients. (SeeWarnings: ClinicalWorsening and Suicide Risk, Precautions: Information for Patients, and Precautions: Pediatric Use)
Phenelzine Sulfate Tablets, USP (phenelzine sulfate) is a potent inhibitor of monoamine oxidase (MAO). Phenelzine sulfate is a hydrazine derivative. It has a molecular weight of 234.27 and is chemically described as C8 H12 N2 • H2 SO4 . Its chemical structure is shown below:
Each Phenelzine Sulfate Tablets film-coated for oral administration contains phenelzine sulfate equivalent to 15 mg of phenelzine base and the following inactive ingredients: mannitol, USP; colloidal silicon dioxide, NF; povidone, USP; edentate disodium, USP; magnesium stearate, NF; purified water, USP; polyvinyl alcohol part hydrolyzed USP, polyethylene glycol-3350 NF, FD&C yellow # 6, talc USP and
titanium dioxide USP.
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. Therefore, the physician should become familiar with all the effects produced by drugs of this class.
Following a single 30 mg dose of Phenelzine Sulfate Tablets (2 × 15 mg tablets), a mean peak plasma concentration (Cmax ) of 19.8 ng/mL occurred at a time (Tmax ) of 43 minutes postdose.
Phenelzine Sulfate Tablets is extensively metabolized, primarily by oxidation via monoamine oxidase. After oral administration of 13 C6 -phenelzine, 73% of the administered dose was recovered in urine as phenylacetic acid and parahydroxyphenylacetic acid within 96 hours. Acetylation to N2 -acetylphenelzine is a minor pathway.
The mean elimination half-life after a single 30 mg dose is 11.6 hours. Multiple dose pharmacokinetics have not been studied in man.
INDICATIONS AND USAGE
Phenelzine Sulfate Tablets, USP has been found to be effective in 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 with severely depressed patients with endogenous features.
Phenelzine Sulfate Tablets should rarely be the first antidepressant drug used. Rather, it is more suitable for use with patients who have failed to respond to the drugs more commonly used for these conditions.
Phenelzine Sulfate Tablets should not be used in patients who are hypersensitive to the drug or its ingredients, with pheochromocytoma, congestive heart failure, severe renal impairment or renal disease, a 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 (see WARNINGS). Therefore, patients being treated with Phenelzine Sulfate Tablets should not take 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 Sulfate Tablets therapy may also be caused by the ingestion of foods with a high concentration of tyramine or dopamine. Therefore, patients being treated with Phenelzine Sulfate Tablets 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 and chocolate may also cause hypertensive reactions.
Phenelzine Sulfate Tablets should not be used in combination with dextromethorphan or with CNS depressants such as alcohol and certain narcotics. Excitation, seizures, delirium, hyperpyrexia, circulatory collapse, coma, and death have been reported in patients receiving MAOI therapy who have been given a single dose of meperidine. Phenelzine Sulfate Tablets should not be administered together with or in rapid succession to other MAO inhibitors because HYPERTENSIVE CRISES and convulsive seizures, fever, marked sweating, excitation, delirium, tremor, coma, and circulatory collapse may occur.
Concomitant use with meperidine is contraindicated (see WARNINGS).
A List of MAO Inhibitors by Generic Name Follows:
pargyline hydrochloride and methylclothiazide
Phenelzine Sulfate Tablets should also not be used in combination with buspirone HCl, since several cases of elevated blood pressure have been reported in patients taking MAO inhibitors who were then given buspirone HCl. At least 14 days should elapse between the discontinuation of Phenelzine Sulfate Tablets and the institution of another antidepressant or buspirone HCl, or the discontinuation of another MAO inhibitor and the institution of Phenelzine Sulfate Tablets.
There have been reports of serious reactions (including hyperthermia, rigidity, myoclonic movements and death) when serotoninergic drugs (e.g., dexfenfluramine, fluoxetine, fluvoxamine, paroxetine, sertraline, citalopram, venlafaxine) have been combined with an MAO inhibitor. Therefore, the concomitant use of Phenelzine Sulfate Tablets with serotoninergic agents is contraindicated (see PRECAUTIONS Drug Interactions). At least 14 days should elapse between the discontinuation of an MAO inhibitor and the start of a serotonin re-uptake inhibitor or vice-versa, with the exception of fluoxetine. Allow at least five weeks between discontinuation of fluoxetine and initiation of Phenelzine Sulfate Tablets and at least 14 days between discontinuation of Phenelzine Sulfate Tablets and initiation of fluoxetine, or other serotoninergic agents. Before initiating Phenelzine Sulfate Tablets after using other serotoninergic agents, a sufficient amount of time must be allowed for clearance of the serotoninergic agent and its active metabolites.
The combination of MAO inhibitors and tryptophan has been reported to cause behavioral and neurologic syndromes including disorientation, confusion, amnesia, delirium, agitation, hypomanic signs, ataxia, myoclonus, hyperreflexia, shivering, ocular oscillations, and Babinski signs.
The concurrent administration of an MAO inhibitor and bupropion hydrochloride (Wellbutrin®) is contraindicated. At least 14 days should elapse between discontinuation of an MAO inhibitor and initiation of treatment with bupropion hydrochloride.
Patients taking Phenelzine Sulfate Tablets should not undergo elective surgery requiring general anesthesia. Also, they should not be given cocaine or local anesthesia containing sympathomimetic vasoconstrictors. The possible combined hypotensive effects of Phenelzine Sulfate Tablets and spinal anesthesia should be kept in mind. Phenelzine Sulfate Tablets should be discontinued at least 10 days prior to elective surgery.
MAO inhibitors, including Phenelzine Sulfate Tablets, are contraindicated in patients receiving guanethidine.
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