MAOI (monoamine oxidase inhibitor), irreversible

Marplan (isocarboxazid) Withdrawal

Marplan (isocarboxazid) has a discontinuation pattern similar to Nardil. Less commonly prescribed than Nardil or Parnate, and the same general MAOI considerations apply.

By Dr. Ben Soffer, DO — board-certified physician, at-home ketamine therapy in Florida and New Jersey.

Half-life

~36 hours (but enzyme inhibition persists ~2 weeks).

Withdrawal timeline

Onset— 3-7 days after the last dose

Onset is gradual.

Peak— Week 2-3

Returning depression typically peaks in the second or third week.

Resolution— 4-6 weeks

Most patients return to baseline within a month or two.

Common symptoms

  • Sleep disturbance
  • Fatigue
  • Return of depression
  • Mood changes

Less common

  • Headache
  • Mild anxiety

Tapering guidance

  • A typical taper reduces by 10 mg every 1-2 weeks.
  • Same 14-day washout consideration before starting most other antidepressants.
  • Coordinate the taper with the prescribing physician.

Where ketamine therapy fits

Same caution as Nardil. MAOIs require additional clinical oversight when combined with ketamine. Discuss with both prescribing physicians before starting ketamine therapy on Marplan.

Check ketamine therapy eligibilityMedication safety with ketamine

Frequently asked questions

How long does Marplan withdrawal last?

Most patients return to baseline within 4-6 weeks. The pattern is similar to other MAOIs.

Can I do ketamine therapy on Marplan?

MAOIs require additional caution with ketamine. Discuss with both your prescribing physician and a ketamine-prescribing physician before starting.

Important: This page is informational and does not constitute medical advice or a recommendation to start, stop, or change any medication. Tapering psychiatric medications should always be coordinated with the prescribing physician. Compounded ketamine for anxiety, depression, PTSD, and chronic pain is not FDA approved.

Browse all medication withdrawal guides.