Promethazine and codeine and Sevoflurane interaction
Promethazine and codeine and Sevoflurane: 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 Sevoflurane (Ultane) label · effective 2025-01-13
Risk of Respiratory Depression Sevoflurane may cause respiratory depression, which may be augmented by opioid premedication or other agents causing respiratory depression.
Caution should be exercised when administering sevoflurane to susceptible patients (e.g., patients with congenital Long QT Syndrome or patients taking drugs that can prolong the QT interval).
Consider having an anticholinergic and epinephrine available when administering sevoflurane for induction in this patient population.
Benzodiazepines and Opioids Benzodiazepines and opioids would be expected to decrease the MAC of sevoflurane in the same manner as with other inhalational anesthetics.
During maintenance of anesthesia, the required dose of nondepolarizing muscle relaxants is likely to be reduced compared to that during N 2 O/opioid anesthesia.
From the Promethazine and codeine (Promethazine Hydrochloride and Codeine Phosphate) label · effective 2025-12-18
…PROMETHAZINE AND RESPIRATORY DEPRESSION IN CHILDREN; MEDICATION ERRORS; INTERACTIONS WITH DRUGS AFFECTING CYTOCHROME P450 ISOENZYMES; CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS; NEONATAL OPIOID WITHDRAWAL SYNDROME Addiction, Abuse, and Misuse Promethazine HCl and Codeine Phosphate Oral Solution exposes patients and other users to the risks…
Risks from Concomitant Use with 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.
Avoid the use of Promethazine HCl and Codeine Phosphate Oral Solution in patients taking benzodiazepines, other CNS depressants, or alcohol [ see Warnings and Precautions (5.10) , Drug Interactions (7.4) ].
( 5.9 , 7.1 , 7.2 , 7.3 ) 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.
Avoid concurrent use of Promethazine HCl and Codeine Phosphate Oral Solution with alcohol or other central nervous system depressants because additional impairment of central nervous system performance may occur [ see Warnings and Precautions (5.10) ].
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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.