Cyclobenzaprine and Ketamine interaction

Cyclobenzaprine and Ketamine: 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 Cyclobenzaprine (TONMYA) label · effective 2026-08-14

Major

Based on its structural similarity to TCAs, concomitant use of TONMYA with: MAO inhibitors may be life-threatening [see Contraindications (4) ] , Alcohol, barbiturates, and other CNS depressants may increase the risk of adverse reactions associated with these drugs, Tramadol may increase the seizure risk, Guanethidine or other similar acting drugs may block the…

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Moderate

CNS Depression and Risk of Operating a Motor Vehicle or Hazardous Machinery TONMYA monotherapy may cause CNS depression and concomitant use of TONMYA with alcohol, barbiturates, or other CNS depressants may increase the risk of CNS depression [see Drug Interactions (7) ].

Warnings and precautionsby drug classView label on DailyMed
Moderate

CNS Depressants: CNS depressant effects of alcohol, barbiturates, and other CNS depressants may be enhanced ( 5.5 , 7 )

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From the Ketamine (Ketalar) label · effective 2026-03-27

Major

Benzodiazepines, Opioid Analgesics, or other CNS Depressants : Concomitant use may result in profound sedation, respiratory depression, coma, or death.

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Moderate

Benzodiazepines, Opioid Analgesics, or Other CNS Depressants Concomitant use of ketamine with opioid analgesics, benzodiazepines, or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death [see Drug Interactions ( 7.3 )] .

Warnings and precautionsby drug classView label on DailyMed
Moderate

Closely monitor neurological status and respiratory parameters, including respiratory rate and pulse oximetry, when KETALR and opioid analgesics, benzodiazepines, or other CNS depressants are co-administered.

Warnings and precautionsby drug classView label on DailyMed
Moderate

Benzodiazepines, Opioid Analgesics, Or Other CNS Depressants Concomitant use of ketamine with opioid analgesics, benzodiazepines, or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death [see Warnings and Precautions ( 5.9 )] .

Drug interactionsby drug classView label on DailyMed
Minor

Muscle relaxants may be required.

Warnings and precautionsby 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.