Promethazine and dextromethorphan and Venlafaxine interaction

Promethazine and dextromethorphan and Venlafaxine: 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 and dextromethorphan (Promethazine Hydrochloride and Dextromethorphan Hydrobromide) label · effective 2025-08-08

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.

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 (see PRECAUTIONS – Information for Patients…

Warningsby drug classView label on DailyMed

From the Venlafaxine (Venlafaxine Hydrochloride) label · effective 2025-01-31

Major

If concomitant use of Venlafaxine Extended Release Tablets with other serotonergic drugs is clinically warranted, patients should be made aware of a potential increased risk for serotonin syndrome, particularly during treatment initiation and dose increases.

Warnings and precautionsby drug classView label on DailyMed
Major

If concomitant use of Venlafaxine Extended Release Tablets with other serotonergic drugs is clinically warranted, inform patients of the increased risk for serotonin syndrome and monitor for symptoms.

Warnings and precautionsby drug classView label on DailyMed
Moderate

Serotonin Syndrome: Sertotonin syndrome has been reported with SSRIs and SNRIs, including Venlafaxine Extended Release Tablets, both when taken alone, but especially when co-administered with other serotonergic agents.

Warnings and precautionsby drug classView label on DailyMed
Moderate

The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, meperidine, methadone, busipirone, amphetamines, and St.

Warnings and precautionsby drug classView label on DailyMed
Moderate

Monoamine Oxidase Inhibitors (MAOIs) [See Dosage and Administration ( 2.6 and 2.7 ), Contraindications ( 4.1 ), and Warnings and Precautions ( 5.2 ) . ] 7.10 Other Serotonergic Drugs The concomitant use of serotonergic drugs (including other SNRIs, SSRIs, triptans, tricyclic antidepressants, opioids, lithium, buspirone, amphetamines, tryptophan, and St.

Drug interactionsby drug classView label on DailyMed

Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.

Open in the checker

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.