Isocarboxazid (1 brand name, 1 dosage form, 1 route)
Available dosage forms: TABLET.
Routes of administration: ORAL.
Brand Names
- MARPLAN
Boxed Warning
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 with Major Depressive Disorder (MDD) and other psychiatric disorders. Anyone considering the use of Marplan 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. Marplan is not approved for use in pediatric patients ( see Warnings: Clinical Worsening and Suicide Risk , Precautions: Information for Patients , and Precautions: Pediatric Use ) . Pooled analyses of short-term (4 to 16 weeks) placebo-controlled trials of 9 antidepressant drugs (SSRIs and others) in children and adolescents with major depressive disorder (MDD), obsessive compulsive disorder (OCD), or other psychiatric disorders (a total of 24 trials involving over 4400 patients) have revealed a greater risk of adverse events representing suicidal thinking or behavior (suicidality) during the first few months of treatment in those receiving antidepressants. The average risk of such events in patients receiving antidepressants was 4%, twice the placebo risk of 2%. No suicides occurred in these trials.
Indications and Usage
Marplan is indicated for the treatment of depression. Because of its potentially serious side effects, Marplan is not an antidepressant of first choice in the treatment of newly diagnosed depressed patients. The efficacy of Marplan in the treatment of depression was established in 6-week controlled trials of depressed outpatients. These patients had symptoms that corresponded to the DSM-IV category of major depressive disorder; however, they often also had signs and symptoms of anxiety (anxious mood, panic, and/or phobic symptoms) ( see CLINICAL PHARMACOLOGY ). A major depressive episode (DSM-IV) implies a prominent and relatively persistent (nearly every day for at least 2 weeks) depressed or dysphoric mood that usually interferes with daily functioning, and includes at least five of the following nine symptoms: depressed mood, loss of interest in usual activities, significant change in weight and/or appetite, insomnia or hypersomnia, psychomotor agitation or retardation, increased fatigue, feelings of guilt or worthlessness, slowed thinking or impaired concentration, and a suicide attempt or suicidal ideation. The antidepressant effectiveness of Marplan in hospitalized depressed patients, or in endogenomorphically retarded and delusionally depressed patients, has not been adequately studied. The effectiveness of Marplan in long-term use, that is, for more than 6 weeks, has not been systematically evaluated in controlled trials. Therefore, the physician who elects to use Marplan for extended periods should periodically evaluate the long-term usefulness of the drug for the individual patient.
Dosage and Administration
For maximum therapeutic effect, the dosage of Marplan must be individually adjusted on the basis of careful observation of the patient. Dosage should be started with one tablet (10 mg) of Marplan twice daily. If tolerated, dosage may be increased by increments of one tablet (10 mg) every 2 to 4 days to achieve a dosage of four tablets daily (40 mg) by the end of the first week of treatment. Dosage can then be increased by increments of up to 20 mg/week, if needed and tolerated, to a maximum recommended dosage of 60 mg/day. Daily dosage should be divided into two to four dosages. After maximum clinical response is achieved, an attempt should be made to reduce the dosage slowly over a period of several weeks without jeopardizing the therapeutic response. Beneficial effect may not be seen in some patients for 3 to 6 weeks. If no response is obtained by then, continued administration is unlikely to help. Because of the limited experience with systematically monitored patients receiving Marplan at the higher end of the currently recommended dose range of up to 60 mg/day, caution is indicated in patients for whom a dose of 40 mg/day is exceeded (see ADVERSE REACTIONS ).
Contraindications
Marplan (isocarboxazid) should not be administered in combination with any of the following: MAO inhibitors or dibenzazepine derivatives; sympathomimetics (including amphetamines); some central nervous system depressants (including narcotics and alcohol); antihypertensive, diuretic, antihistaminic, sedative or anesthetic drugs, buproprion HCL, buspirone HCL, dextromethorphan, cheese or other foods with a high tyramine content; or excessive quantities of caffeine. Marplan (isocarboxazid) should not be administered to any patient with a confirmed or suspected cerebrovascular defect or to any patient with cardiovascular disease, hypertension, or history of headache. Contraindicated Patient Populations Hypersensitivity Marplan should not be used in patients with known hypersensitivity to isocarboxazid. Cerebrovascular Disorders Marplan should not be administered to any patient with a confirmed or suspected cerebrovascular defect or to any patient with cardiovascular disease or hypertension. Pheochromocytoma Marplan should not be used in the presence of pheochromocytoma, as such tumors secrete pressor substances whose metabolism may be inhibited by Marplan. Liver Disease Marplan should not be used in patients with a history of liver disease, or in those with abnormal liver function tests. Renal Impairment Marplan should not be used in patients with severe impairment of renal function. Contraindicated MAOI-Other Drug Combinations Other MAOI Inhibitors or With Dibenzazepine-Related Entities Marplan should not be administered together with, or in close proximity to, other MAO inhibitors or dibenzazepine-related entities. Hypertensive crises, severe convulsive seizures, coma, or circulatory collapse may occur in patients receiving such combinations. In patients being transferred to Marplan from another MAO inhibitor or from a dibenzazepine-related entity, a medication-free interval of at least 1 week should be allowed, after which Marplan therapy should be started using half
Drug Interactions
See CONTRAINDICATIONS , WARNINGS , and PRECAUTIONS sections for information on drug interactions. Marplan should be administered with caution to patients receiving Antabuse® (disulfiram, Wyeth-Ayerst Laboratories). In a single study, rats given high intraperitoneal doses of an MAO inhibitor plus disulfiram experienced severe toxicity, including convulsions and death. Concomitant use of Marplan and other psychotropic agents is generally not recommended because of possible potentiating effects. This is especially true in patients who may subject themselves to an overdosage of drugs. If combination therapy is needed, careful consideration should be given to the pharmacology of all agents to be used. The monoamine oxidase inhibitory effects of Marplan may persist for a substantial period after discontinuation of the drug, and this should be borne in mind when another drug is prescribed following Marplan. To avoid potentiation, the physician wishing to terminate treatment with Marplan and begin therapy with another agent should allow for an interval of 10 days.
Overdosage
The lethal dose of Marplan in humans is not known. There has been one report of a fatality in a patient who ingested 400 mg of Marplan together with an unspecified amount of another drug. Symptoms: Major overdosage may be evidenced by tachycardia, hypotension, coma, convulsions, respiratory depression, sluggish reflexes, pyrexia, and diaphoresis; these signs may persist for 8 to 14 days. Treatment: General supportive measures should be used, along with immediate gastric lavage or emetics. If the latter are given, the danger of aspiration must be borne in mind. An adequate airway should be maintained, with supplemental oxygen if necessary. The mechanism by which amine-oxidase inhibitors produce hypotension is not fully understood, but there is evidence that these agents block the vascular bed response. Thus it is suggested that plasma may be of value in the management of this hypotension. Administration of pressor amines such as Levophed® (levarterenol bitartrate) may be of limited value (note that their effects may be potentiated by Marplan). Continue treatment for several days until homeostasis is restored. Liver function studies are recommended during the 4 to 6 weeks after recovery, as well as the time of overdosage. In managing overdosage, consider the possibility of multiple drug involvement. The physician should consider contacting a poison control center on the treatment of any overdose.