Midazolam and Promethazine interaction

Midazolam and Promethazine: 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 Midazolam (Midazolam in Sodium Chloride) label · effective 2025-07-31

Major

WARNING: PERSONNEL AND EQUIPMENT FOR MONITORING AND RESUSCITATION, AND RISKS FROM CONCOMITANT USE WITH OPIOID ANALGESICS AND OTHER SEDATIVE-HYPNOTICS Personnel and Equipment for Monitoring and ResuscitationOnly personnel trained in the administration of procedural sedation, and not involved in the conduct of the diagnostic or therapeutic procedure, should administer…

Boxed warningby drug classView label on DailyMed
Major

Risks from Concomitant Use with Opioids, Other Sedative Hypnotics, or Other Central Nervous System Depressants Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death.

Warnings and precautionsby drug classView label on DailyMed
Major

Opioid Analgesics and Other Sedative Hypnotics : Risk of respiratory depression is increased ( 7.1 )

Drug interactionsby drug classView label on DailyMed
Major

Opioid Analgesics and Other Sedative Hypnotics The concomitant use of benzodiazepines and opioids increases the risk of respiratory depression because of actions at different receptor sites in the CNS that control respiration.

Drug interactionsby drug classView label on DailyMed
Moderate

Because intravenous midazolam can depress respiration [see Clinical Pharmacology (12)] , especially when used concomitantly with opioid agonists and other sedatives [see Dosage and Administration (2)] , it should be used for sedation/anxiolysis/amnesia only in the presence of personnel skilled in early detection of hypoventilation, maintaining a patent airway,…

Warnings and precautionsby drug classView label on DailyMed

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

Moderate

The impairment may be amplified by 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…

Warningsby drug classView label on DailyMed
Moderate

Drug Interactions CNS Depressants Promethazine Syrup may increase, 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…

Drug interactionsby drug classView label on DailyMed
Moderate

CNS Depressants Promethazine Syrup may increase, 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…

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.