Non-selective irreversible MAOI Pregnancy: §4.6 — No data from use in pregnant women; animal studies are insufficient with respect to reproduction toxicity. Tranylcypromine should not be used in pregnancy unless considered essential by the physician. Breast-feeding: the drug is excreted in human milk and a risk to the suckling child cannot be excluded — decide whether to discontinue breast-feeding or therapy. No fertility data available.

Tranylcypromine

Brand names: Parnate

Tranylcypromine is a non-selective, irreversible monoamine oxidase inhibitor (MAOI) used in the treatment of depression, including treatment-resistant illness.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Initially 10 mg in the morning and 10 mg in the afternoon; if the response is not adequate after the first week add 10 mg at midday and continue for at least a week

Route: Oral (tablets swallowed whole with a glass of water)

Frequency: Twice daily initially (morning and afternoon), increasing to three times daily (morning, midday, afternoon) if needed; maintenance often 10 mg a day

Max: A dosage of 30 mg a day should only be exceeded with caution (UK SPC §4.2)

Source: UK SPC (eMC) for Tranylcypromine 10 mg Film-Coated Tablets, §4.2 (https://www.medicines.org.uk/emc/product/101958/smpc). MAINTENANCE: when a satisfactory response has been obtained, dosage may be reduced to maintenance level, often of 10 mg a day. WITH A TRANQUILLIZER: §4.2 states 'When given with a tranquillizer, the dosage of tranylcypromine is not affected'. WITH ELECTROCONVULSIVE THERAPY: the usual dosage is 10 mg twice a day during the series and 10 mg a day afterwards as maintenance therapy. ELDERLY: daily doses should be kept as low as possible; dose increases should be made more slowly and blood pressure checked regularly (older patients may be at greater risk of postural hypotension). HEPATIC IMPAIRMENT: tranylcypromine should not be used in patients with a history of liver disease or in those with abnormal liver function tests (§4.3 — known liver damage is a contraindication). PAEDIATRIC: §4.2 states 'Tranylcypromine is not indicated for children under 18 years of age' — no paediatric dose is given. Verify any under-18 use against a children's formulary. WITHDRAWAL (§4.4): tranylcypromine therapy should be withdrawn gradually; it should preferably be withdrawn at least two weeks before elective surgery because of possible drug interaction. US LABELLING DIFFERS — the US FDA label in this bundle (Solco Healthcare, 2024-12-20) recommends 30 mg per day in divided doses, increased in 10 mg/day increments every 1 to 3 weeks to a maximum of 30 mg twice daily (60 mg/day); the UK SPC figure above (30 mg/day, exceed only with caution) has been used. The eMC §4.5 interaction section was truncated at the source-fetch limit ('Caution should be exercised when giving…') — the interaction list below is drawn from the §4.3 contraindications and must be checked against the full §4.5, including the tyramine-containing food restriction referenced in §4.8.

Dose adjustments

Renal

§4.2/§4.4 — There is limited clinical data on the safety of tranylcypromine in patients with severe renal impairment. In patients with mild to moderate renal impairment, tranylcypromine should be used with caution and patients should be monitored accordingly. No dose-banded adjustment is stated.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Do not give until at least two weeks after stopping treatment with other MAOIs
Indirectly acting sympathomimetic amines (amphetamine, fenfluramine or similar anti-obesity agents, ephedrine, phenylpropanolamine — certain cold cures may contain these), levodopa or dopamine — severe hypertensive reactions may result
Pethidine and closely related narcotic analgesics, and nefopam (potentiation); dextromethorphan; other MAO inhibitors; buspirone (increased blood pressure)
Tricyclic antidepressants (reports of hyperactivity, hypertonicity, hyperpyrexia, coma and death); tetracyclic antidepressants should also be avoided; allow 3 weeks after stopping tranylcypromine before starting clomipramine or imipramine; MAOIs with or after fluvoxamine has produced serotonin syndrome, sometimes fatal
Porphyria
Actual or suspected cerebrovascular disease or severe cardiovascular disease
Actual or suspected phaeochromocytoma
Hyperthyroidism
Known liver damage
Blood dyscrasias

Side effects

Insomnia (the most frequent side effect; may be overcome by giving the last dose of the day not later than 3 p.m., reducing dosage, or prescribing a mild hypnotic)
Vascular: orthostatic/postural hypertension; hypertensive crisis (may be preceded by throbbing headache as an early warning; symptoms include neck pain and stiffness, multiple extrasystoles often with substernal pain, sweating and pallor, sometimes followed by flushing, mydriasis and photophobia)
Psychiatric (rare): hallucinations, hypomania, drug dependence with tolerance; not known — anxiety, agitation, restlessness, suicidal ideation and suicidal behaviours
Nervous system: dizziness, somnolence, headache, sleep disturbances; rare paraesthesia and peripheral neuritis
Gastrointestinal: dry mouth, diarrhoea, nausea, vomiting
Hepatobiliary (rare): hepatocellular injury, jaundice; blood dyscrasias (rare); fatigue, weight gain, fluid retention

Interactions

MAOIs — do not give tranylcypromine until at least two weeks after stopping another MAOI (§4.3)
Indirectly acting sympathomimetic amines, levodopa, dopamine — severe hypertensive reactions may result (§4.3)
Pethidine and closely related narcotic analgesics, nefopam, dextromethorphan — potentiation/severe reactions (§4.3)
Tricyclic and tetracyclic antidepressants, fluvoxamine — hyperactivity, hypertonicity, hyperpyrexia, coma, death and serotonin syndrome reported; allow 3 weeks after stopping tranylcypromine before clomipramine or imipramine (§4.3)
Buspirone — increased blood pressure (§4.3)
Tyramine-containing foods — §4.8 records severe, occasionally fatal hypertensive reactions 'notably in association with foods containing tyramine (see section 4.5)'. The full §4.5 was not retrieved in this bundle.

Clinical monograph

How it works

It irreversibly inhibits monoamine oxidase, increasing central levels of serotonin, noradrenaline and dopamine; it also has a mild amphetamine-like stimulant effect.

Prescribing in practice

Patients must avoid tyramine-rich foods and interacting sympathomimetic or serotonergic drugs because of the risk of severe hypertensive crisis and serotonin syndrome.
Appropriate washout periods are required when switching to or from other antidepressants.
Insomnia and a stimulant effect are common, and abrupt withdrawal should be avoided.

Monitoring

Monitor blood pressure and mental state, remaining alert for hypertensive crisis and serotonin toxicity.

Counselling the patient

Follow the food and medicine restrictions you are given, including avoiding mature cheese, cured meats and yeast extracts.
Always tell a pharmacist or doctor that you take a MAOI before taking any new medicine, including cough and cold remedies.
Seek urgent help for a severe throbbing headache, palpitations or chest pain.

Evidence & guidelines

The dietary and drug precautions for irreversible MAOIs such as tranylcypromine are well established and reinforced by MHRA and SPC guidance.

Reference: NICE NG222; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Drugs

Isocarboxazid · Non-selective irreversible MAOI

Pathways