What is Marplan and how does it work?
Marplan, or isocarboxazid, is a potent MAOI antidepressant used for major depressive disorder in adults who haven't responded to other treatments. It works by inhibiting the MAO enzyme, increasing brain levels of dopamine, norepinephrine, and serotonin, which are vital for mood regulation.
Primary therapeutic use for Marplan
Marplan is not a first-line treatment due to its risks, and is reserved for specific situations like treatment-resistant depression and depression with atypical features, such as anxiety, panic, or phobias, when other antidepressants haven't been effective. It is not approved for children and should not be used for bipolar depression due to the risk of inducing mania. Prescribing Marplan involves a careful assessment of risks versus benefits.
Important considerations and risks
Marplan requires close medical supervision due to serious risks like hypertensive crisis (from interactions with tyramine-rich foods or certain medications), serotonin syndrome (from combining with other serotonergic drugs like SSRIs), and an increased risk of suicidal thoughts and behavior, especially in young adults. Other risks include potential liver damage and orthostatic hypotension.
Common side effects
Common side effects include dizziness, headache, dry mouth, constipation, nausea, and insomnia.
Drug and food interactions
Avoiding specific foods and medications is critical with Marplan. A strict low-tyramine diet must be followed during treatment and for at least two weeks after stopping the medication.
Foods to avoid while taking Marplan:
- Aged or fermented foods (cheeses, sauerkraut, soy sauce)
- Cured or smoked meats and fish
- Some fruits and vegetables (overripe bananas and avocados, fava beans)
- Yeast and meat extracts
- Alcoholic beverages, especially red wine and beer
- Excessive caffeine
Key drug interactions:
- Other MAOIs
- SSRIs and other serotonergic drugs
- Sympathomimetics (amphetamines, many cold medicines)
- Certain narcotic pain medications (meperidine, tramadol)
- Some antihypertensive agents
- Dextromethorphan (cough suppressant)
Marplan's place in treatment: a comparison
| Feature | Marplan (MAOI) | Modern Antidepressants (SSRIs/SNRIs) |
|---|---|---|
| Usage | Primarily for treatment-resistant depression | First-line treatment for depression, anxiety, etc. |
| Mechanism | Inhibits MAO, increasing dopamine, norepinephrine, and serotonin | Selectively increases serotonin (SSRIs) or serotonin and norepinephrine (SNRIs) |
| Dietary Restrictions | Requires strict, permanent tyramine-restricted diet | No significant dietary restrictions |
| Drug Interactions | Numerous and potentially fatal interactions | Fewer and less severe interactions overall |
| Side Effect Profile | Includes risks like hypertensive crisis, serotonin syndrome, orthostatic hypotension | Generally more manageable, though side effects vary widely |
| Monitoring | Requires frequent blood pressure monitoring and patient education | Less intensive monitoring for most patients |
Dosage and administration
Marplan is taken orally, typically starting at a low dose and gradually increased under medical supervision until a therapeutic effect is achieved, which can take several weeks. Abruptly stopping Marplan can cause withdrawal symptoms, so any dosage change or discontinuation must be discussed with a healthcare provider.
Conclusion
Although less commonly used now, Marplan remains a valuable treatment option for severe, treatment-resistant depression. Its effectiveness is coupled with significant risks and the need for strict adherence to dietary and drug interaction guidelines. With careful patient selection and vigilant medical supervision, Marplan can provide significant relief. For more detailed information, consult the official FDA-approved product labeling at a source like DailyMed: https://dailymed.nlm.nih.gov/dailymed/.
