Fact Sheet

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Marplan^® (isocarboxazid) Facts

Identifying Treatment Resistant Depression

• Failure to respond to 3 or more adequate trials is frequently considered to be the standard for categorizing a patient as Treatment-Resistant.

Use of Mao-Inhibitors in Treatment-Resistant Depression

• ECT has long been considered the primary option for treatment-resistant depression, but high rates of relapse, cognitive side effects, and poor acceptability make this option problematic.
• Monoamine oxidase inhibitors (MAOIs), such as Marplan, have been used as an alternative to ECT for treatment-resistant depression.
• Marplan is unique among the irreversible MAOIs in having the largest body of placebo-controlled clinical trial data supporting the safety and efficacy of its use for the treatment of depression.

Marplan^® (isocarboxazid) titration

• 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 10 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.

Importance of food choices when taking Marplan^® (isocarboxazid)

Newer Findings = Less Restrictive Dietary Guidelines

The Key is Fresh Foods

However, you'll want to counsel patients to avoid any aged cheeses, fermented/dry/aged meats such as salami, most soy products, and any foods that haven't been stored properly or have gone beyond their expiration dates.

It is best to avoid Alcohol

The good news is that patients can benefit from MAO-Inhibiting medications like Marplan while consuming most of the foods and beverages that they like-including a number of foods that were incorrectly thought to be 'off-limits'.

Drug interactions

Medication combinations that should be avoided:

• Marplan should be administered with caution to patients receiving Antabuse^® (disulfiram)
• The use of Marplan in combination with other psychotropic agents is not recommended because one product can potentially magnify the effects of the other.
• The MAO-Inhibiting effects of Marplan can persist for a substantial period after it has been discontinued, so it is best for patients to wait at least 10 days before taking any other psychotropic medication
• Marplan should not be used with:
  • other MAO-Inhibitors, tri-cyclic medications (dibenzazepine-related and other); Wellbutrin^® (buproprion); SSRI antidepressants; Buspar^® (buspirone);
  • sympathomimetic drugs, including amphetamines, and over-the- counter cold, hay fever or weight-reducing preparations containing vasoconstrictors (decongestants); tryptophan; Demerol^® (meperidine); the cough-preventive dextromethorphan;
  • anestheic agents; blood pressure drugs, including thiazide diuretics; excessive amounts of caffeine; central nervous system depressants such as narcotics, barbiturates, and alcohol.

Meta-analyses of Marplan Clinical Trials

• In 1995 Thase, et al¹, conducted a meta-analysis of 12 randomized controlled trials in 434 depressed patients, comparing FDA-approved MAO-I drugs. Using the Intent–To-Treat sample method, the authors concluded that Marplan exhibited a 41.3% average difference vs. placebo in the number of patients randomized to treatment who demonstrated improvement.
• Intent-to-treat samples in five of these 12 studies revealed a Marplan efficacy rate of 60.1%.
• The 1984 study of Giller, et al², one of seven placebo-controlled studies in the meta-analysis, out-patients who were crossed over from placebo (due to lack of response) achieved a 69% response rate with Marplan treatment.

1. Thase, ME, et al. (1995): MAOIs in the Contemporary Treatment of Depression. Neuropsychopharmacology 12(3):202-203.
2. Giller, E, et al. (1984): Assessing Treatment Response to the Monoamine Oxidase Inhibitor Isocarboxazid. Journal of Clinical Psychiatry 45:44-48.

Please see Full Prescribing Information including BOXED WARNINGS regarding increased risk of suicidality in children and adolescents. MAO-Inhibitors are contraindicated with certain drugs. Potential hypertensive crises may occur with foods that contain tyramine. As with all antidepressants, patients should be observed closely for clinical worsening, suicidality, and unusual changes in behavior, especially during the initial few months of treatment.