MAOI (monoamine oxidase inhibitor), irreversible

Nardil (phenelzine) Withdrawal

Nardil (phenelzine) has a discontinuation pattern that is pharmacologically benign compared to SSRIs, but the dietary restrictions ending and the gradual return of normal MAO function over 2 weeks produces its own pattern. Patients tapering MAOIs often describe sleep changes and the return of depression as the dominant experiences.

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

Half-life

~11 hours (but enzyme inhibition persists ~2 weeks because MAO enzyme must be regenerated).

Withdrawal timeline

Onset— 3-7 days after the last dose

Enzyme regeneration is gradual, so symptoms emerge over the first week.

Peak— Week 2-3

Returning depression, if it occurs, often becomes apparent in the second or third week as MAO function normalizes.

Resolution— 4-6 weeks

Most patients return to baseline within a month or two.

Common symptoms

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

Less common

  • Headache
  • Mild anxiety

Notable / pattern-defining symptoms

Dietary tyramine restrictions can typically be relaxed about 2 weeks after the last dose, when MAO enzyme function has been substantially restored. Discuss specific timing with the prescribing physician.

A 14-day washout is required before starting an SSRI/SNRI after MAOI discontinuation, to prevent serotonin syndrome.

Tapering guidance

  • A typical taper reduces by 15 mg every 1-2 weeks.
  • The 14-day washout before starting most other antidepressants is the most clinically important consideration after the taper completes.
  • Coordinate the taper with the prescribing physician.

Where ketamine therapy fits

MAOIs require additional caution with ketamine. While serious interactions with ketamine are uncommon, the combination warrants careful clinical oversight. Patients on MAOIs should discuss ketamine therapy with both their prescribing physician and a ketamine-prescribing physician before starting. In many cases the conversation involves completing the MAOI taper first and observing the depression's response before adding ketamine.

Check ketamine therapy eligibilityMedication safety with ketamine

Frequently asked questions

How long until I can eat tyramine foods after stopping Nardil?

Typically about 2 weeks after the last dose, when MAO enzyme function has been substantially restored. Discuss specific timing with the prescribing physician.

Can I start an SSRI right after stopping Nardil?

No. A 14-day washout is required before starting most other antidepressants after MAOI discontinuation to prevent serotonin syndrome.

Can I do ketamine therapy on Nardil?

MAOIs require additional caution with ketamine. Discuss specifically 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.

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