Promethazine and Tranylcypromine interaction

Promethazine and Tranylcypromine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Promethazine (PROMETHAZINE HYDROCHLORIDE) label · effective 2026-04-16

Major

…prolong, or intensify the sedative action of other central-nervous-system depressants, such as alcohol, sedatives/hypnotics (including barbiturates), narcotics, narcotic analgesics, general anesthetics, tricyclic antidepressants, and tranquilizers; therefore, such agents should be avoided or administered in reduced dosage to patients receiving promethazine HCl.

Drug interactionsby drug classView label on DailyMed
Major

…prolong, or intensify the sedative action of other central-nervous-system depressants, such as alcohol, sedatives/hypnotics (including barbiturates), narcotics, narcotic analgesics, general anesthetics, tricyclic antidepressants, and tranquilizers; therefore, such agents should be avoided or administered in reduced dosage to patients receiving promethazine HCl.

Drug interactionsby drug classView label on DailyMed
Moderate

…concomitant use of other central-nervous-system depressants such as alcohol, sedatives/hypnotics (including barbiturates), narcotics, narcotic analgesics, general anesthetics, tricyclic antidepressants, and tranquilizers; therefore such agents should either be eliminated or given in reduced dosage in the presence of promethazine HCl (see PRECAUTIONS-Information for…

Warningsby drug classView label on DailyMed
Moderate

Monoamine Oxidase Inhibitors (MAOI) Drug interactions, including an increased incidence of extrapyramidal effects, have been reported when some MAOI and phenothiazines are used concomitantly.

Drug interactionsby drug classView label on DailyMed

From the Tranylcypromine (Tranylcypromine Sulfate) label · effective 2025-07-25

Major

These medicines are in some cold, hay fever or weight-loss medicines. sympathomimetic herbal medicines or dietary supplements antihistamines (allergy medicines) triptans buspirone carbamazepine dextromethorphan dopamine hydroxytryptophan and tryptophan levodopa and methyldopa meperidine rasagline resperine s-adenosyl-L-methionine (SAM-e) tapentadol tetrabenazin…

Boxed warningby drug classView label on DailyMed
Major

Table 1: Products Contraindicated with the Use of Tranylcypromine Sulfate Tablets Drug Classes Non-selective H1 receptor antagonists Antidepressants including but not limited to: Other monoamine oxidase inhibitors (MAOIs) Selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs) Tricyclic antidepressants Other…

Contraindicationsby drug classView label on DailyMed
Major

…Use a Predominant Effect/Risk [Hypertensive Reaction (HR) b or Serotonin Syndrome (SS) c ] Agents with blood pressure-reducing effects Use with caution d Hypotension e Non-selective H1 receptor antagonists Contraindicated a Increased anticholinergic effects Beta-adrenergic blockers (see also agents or procedures with blood pressure-reducing effects) Use with the…

Drug interactionsby drug classView label on DailyMed
Moderate

Excessive reduction of blood glucose (additive effect) f CNS depressant agents (including opioids, alcohol, sedatives, hypnotics) Use with caution d Increased CNS depression Dietary supplements containing sympathomimetics Contraindicated a Antidepressants including but not limited to: Other MAOIs (e.g., linezolid, intravenous methylene blue, selective MAOIs)…

Drug interactionsby drug classView label on DailyMed

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Not medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.