Patients should be instructed to report promptly the occurrence of headache or other unusual symptoms, i. e., palpitation and or tachycardia, a sense of constriction in the throat or chest, sweating, dizziness, neck stiffness, nausea, or vomiting. Patients should be warned against eating the foods listed under CONTRAINDICATIONS while on Marplan therapy and should also be told not to drink alcoholic beverages. The patient should also be warned about the possibility of hypotension and faintness, as well as drowsiness sufficient to impair performance of potentially hazardous tasks, such as driving a car or operating machinery.
Patients should also be cautioned not to take concomitant medications, whether prescription or over-the- counter drugs such as cold, hay fever, or weight-reducing preparations, without the advice of a physician. They should be advised not to consume excessive amounts of caffeine in any form. Likewise, they should inform their physicians and their dentist about the use of Marplan.
Isocarboxazid 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 Isocarboxazid 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 Isocarboxazid may persist for a substantial period after discontinuation of the drug, and this should be borne in mind when another drug is prescribed following Isocarboxazid. To avoid potentiation, the physician wishing to terminate treatment with Isocarboxazid and begin therapy with another agent should allow for an interval of 10 days.
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
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.
Marplan should not be used in the presence of pheochromocytoma, as such tumors secrete pressor substances whose metabolism may be inhibited by Marplan.
Marplan should not be used in patients with a history of liver disease, or in those with abnormal liver function tests.
Marplan should not be used in patients with severe impairment of renal function. Patients with Severe/ Frequent Headaches Patients with severe or frequent headaches should not be considered candidates for therapy with Marplan, because headaches during therapy may be the first symptom of a hypertensive reaction to the drug.
Contraindicated MAOI-Other Drug Combinations
Other MAO 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 the normal starting dosage for at least the first week of therapy. Similarly, at least 1 week should elapse between the discontinuation of Marplan and initiation of another MAO inhibitor or dibenzazepine-related entity, or the readministration of Marplan. The following list includes some other MAO inhibitors, dibenzazepine-related entities, and tricyclic antidepressants.
|Generic Name||Trademark (Manufacturer)|
|Other MAO Inhibitors|
|Furazolidone||Furoxone® (Roberts Laboratories)|
|Pargyline HCL||Eutonyl® (Abbott Laboratories)|
|Pargyline HCL and methyclothiazide||Eutron® (Abbott Laboratories)|
|Phenelzine sulfate||Nardil® (Parke-Davis)|
|Procarbazine||Matulane® (Roche Laboratories)|
|Tranylcypromine sulfate||Parnate® (SmithKline Beecham Pharmaceuticals)|
|Dibenzazepine- Related and Other Tricyclics|
|Amitriptyline HCL||Elavil® (Zeneca)|
|Endep® (Roche Products)|
|Perphenazine and amitriptyline HCL||Etrafon® (Schering)|
|Triavil® (Merck Sharp & Dohme)|
|Clomipramine hydrochloride||Anafranil® (Novartis)|
|Desipramine HCL||Norpramin® (Hoechst Marion Roussel)|
|Pertofrane® (Rhône-Poulenc Rorer Pharmaceuticals)|
|Imipramine HCL||Janimine® (Abbott Laboratories)|
|Nortriptyline HCL||Aventyl® (Eli Lilly & Co.)|
|Protripyline HCL||Vivactil® (Merck Sharp & Dohme)|
|Doxepin HCL||Adapin® (Fisons)|
|Cyclobenzaprine HCL||Flexeril® (Merck Sharp & Dohme)|
|Maprotiline HCL||Ludiomil® (Novartis)|
|Trimipramine maleate||Surmontil® (Wyeth-Ayerst Laboratories)|
The concurrent administration of an MAO inhibitor and bupropion hydrochloride (Wellbutrin® and Zyban®, Glaxo Wellcome) is contraindicated. At least 14 days should elapse between discontinuation of an MAO inhibitor and initiation of treatment with bupropion hydrochloride.
Selective Serotonin Reuptake Inhibitors (SSRIs)
Marplan should not be administered in combination with any SSRI. There have been reports of serious, sometimes fatal, reactions (including hyperthermia, rigidity, myoclonus, autonomic instability with possible rapid fluctuations of vital signs, and mental status changes that include extreme agitation and confusion progressing to delirium and coma) in patients receiving fluoxetine (Prozac®, Lilly) in combination with a monoamine oxidase inhibitor (MAOI), and in patients who have recently discontinued fluoxetine and are then started on an MAOI. Some cases presented with features resembling neuroleptic malignant syndrome. Fluoxetine and other SSRIs should therefore not be used in combination with Marplan, or within 14 days of discontinuing therapy with Marplan. As fluoxetine and its major metabolite have very long elimination half-lives, at least 5 weeks should be allowed after stopping fluoxetine before starting Marplan. At least 2 weeks should be allowed after stopping sertraline (Zoloft®, Pfizer) or paroxetine (Paxil®, SmithKline Beecham Pharmaceuticals) before starting Marplan. In addition, there should be an interval of at least 10 days between discontinuation of Marplan and initiation of fluoxetine or other SSRIs. Buspirone Marplan should not be used in combination with buspirone HCL (Buspar®, Bristol-Myers Squibb); several cases of elevated blood pressure have been reported in patients taking MAO inhibitors who were then given buspirone HCL. At least 10 days should elapse between the discontinuation of Marplan and the institution of buspirone HCL.
Marplan should not be administered in combination with sympathomimetics, including amphetamines, or with over-the-counter drugs such as cold, hay fever, or weight-reducing preparations that contain vasoconstrictors. During Marplan therapy, it appears that some patients are particularly vulnerable to the effects of sympathomimetics when the activity of metabolizing enzymes is inhibited. Use of sympathomimetics and compounds such as guanethidine, methyldopa, methylphenidate, reserpine, epinephrine, norepinephrine, phenylalanine, dopamine, levodopa, tyrosine, and tryptophan with Marplan may precipitate hypertension, headache, and related symptoms. The combination of MAO inhibitors and tryptophan has been reported to cause behavioral and neurologic symptoms, including disorientation, confusion, amnesia, delirium, agitation, hypomanic signs, ataxia, myoclonus, hyperreflexia, shivering, ocular oscillations, and Babinski signs.
Meperidine should not be used concomitantly with MAO inhibitors or within 2 or 3 weeks following MAO therapy. Serious reactions have been precipitated with concomitant use, including coma, severe hypertension or hypotension, severe respiratory depression, convulsions, malignant hyperpyrexia, excitation, peripheral vascular collapse, and death. It is thought that these reactions may be mediated by accumulation of 5-HT (serotonin) consequent to MAO inhibition.
Marplan should not be used in combination with dextromethorphan. The combination of MAO inhibitors and dextromethorphan has been reported to cause brief episodes of psychosis or bizarre behavior.
Cheese or Other Foods with a High Tyramine
Content Hypertensive crises have sometimes occurred during Marplan therapy after ingestion of foods with a high tyramine content. In general, patients should avoid protein foods in which aging or protein breakdown is used to increase flavor. In particular, patients should be instructed not to take foods such as cheese (particularly strong or aged varieties), sour cream, Chianti wine, sherry, beer (including non-alcoholic beer), liqueurs, pickled herring, anchovies, caviar, liver, canned figs, raisins, bananas or avocados (particularly if overripe), chocolate, soy sauce, sauerkraut, the p.d. of broad beans (fava beans), yeast extracts, yogurt, meat extracts, meat prepared with tenderizers, or dry sausage.
Patients taking Marplan 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 Marplan and spinal anesthesia should be kept in mind. Marplan should be discontinued at least 10 days before elective surgery.
Marplan should not be used in combination with some central nervous system depressants, such as narcotics, barbiturates, or alcohol.
Marplan should not be used in combination with antihypertensive agents, including thiazide diuretics. A marked potentiating effect on these drugs has been reported, resulting in hypotension.
Excessive use of caffeine in any form should be avoided in patients receiving Marplan.