Belladonna and opium and Promethazine and dextromethorphan interaction
Belladonna and opium and Promethazine and dextromethorphan: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Belladonna and opium label · effective 2024-01-11
…AND MISUSE; LIFE-THREATENING RESPIRATORY DEPRESSION; ACCIDENTAL EXPOSURE; NEONATAL OPIOD WITHDRAWAL SYNDROME; and RISKS FROM CONCOMITANT USE WITH ALCOHOL, BENZODIAZEPINES OR OTHER CNS DEPRESSANTS Addiction, Abuse, and Misuse Belladonna and opium suppositories expose patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to…
Risks From Concomitant Use With Alcohol, Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death [ see Warnings and Precautions (5.4), Drug Interactions (7) ].
• Reserve concomitant prescribing of belladonna and opium suppositories and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate.
…Follow patients for signs and symptoms of respiratory depression and sedation WARNING: ADDICTION, ABOUSE, AND MISUSE; LIFE-THREATENING RESPIRATORY DEPRESSION; ACCIDENTAL EXPOSURE; NEONATAL OPIOD WITHDRAWAL SYNDROME; and RISKS FROM CONCOMITANT USE WITH ALCOHOL, BENZODIAZEPINES OR OTHER CNS DEPRESSANTS See full prescribing information for complete boxed warning.
• Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death.
From the Promethazine and dextromethorphan (Promethazine Hydrochloride and Dextromethorphan Hydrobromide) label · effective 2025-08-08
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…
It should be used with caution in persons with seizure disorders or in persons who are using concomitant medications, such as narcotics or local anesthetics, which may also affect seizure threshold.
CNS Depressants – Promethazine 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…
When given concomitantly with Promethazine Hydrochloride and Dextromethorphan Hydrobromide Oral Solution, the dose of barbiturates should be reduced by at least one-half, and the dose of narcotics should be reduced by one-quarter to one-half.
Excessive amounts of promethazine relative to a narcotic may lead to restlessness and motor hyperactivity in the patient with pain; these symptoms usually disappear with adequate control of the pain.
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Open in the checkerNot 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.