Cyclobenzaprine and Lofexidine interaction

Cyclobenzaprine and Lofexidine: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.

Moderate

Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.

What the FDA labels say

From the Cyclobenzaprine (TONMYA) label · effective 2026-08-14

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

…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 antihypertensive action of these drugs.

Drug interactionsby drug classView label on DailyMed
Minor

Guanethidine: Antihypertensive effect may be blocked ( 7 )

Drug interactionsby drug classView label on DailyMed

From the Lofexidine label · effective 2026-07-22

Moderate

Increased Risk of CNS Depression with Concomitant use of CNS Depressant Drugs : Lofexidine tablets potentiates the CNS depressant effects of benzodiazepines and may potentiate the CNS depressant effects of alcohol, barbiturates, and other sedating drugs.

Warnings and precautionsby drug classView label on DailyMed
Moderate

Increased Risk of Central Nervous System Depression with Concomitant use of CNS Depressant Drugs Lofexidine tablets potentiates the CNS depressive effects of benzodiazepines and can also be expected to potentiate the CNS depressive effects of alcohol, barbiturates, and other sedating drugs.

Warnings and precautionsby drug classView label on DailyMed
Moderate

CNS Depressant Drugs Lofexidine tablets potentiates the CNS depressant effects of benzodiazepines and may potentiate the CNS depressant effects of alcohol, barbiturates, and other sedating drugs.

Drug interactionsby 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.