Cyclobenzaprine and Doxepin interaction
Cyclobenzaprine and Doxepin: 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 Cyclobenzaprine (TONMYA) label · effective 2026-08-14
Hyperpyretic crisis seizures and deaths have occurred in patients who received cyclobenzaprine (or structurally similar tricyclic antidepressants) concomitantly with MAO inhibitors drugs.
Immediately discontinue concomitant treatment with TONMYA and a serotonergic agent if serotonin syndrome symptoms occur and initiate supportive symptomatic treatment.
Treatment with TONMYA and any concomitant serotonergic agents should be discontinued immediately if serotonin syndrome symptoms occur and supportive symptomatic treatment should be initiated.
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…
If serotonin syndrome symptoms occur with the use of other serotonergic drugs, immediately discontinue TONMYA.
From the Doxepin (Silenor) label · effective 2026-04-21
Potential additive effects when used in combination with CNS depressants or sedating antihistamines.
Although behaviors such as "sleep-driving" may occur with hypnotics alone at therapeutic doses, the use of alcohol and other CNS depressants with hypnotics appears to increase the risk of such behaviors, as does the use of hypnotics at doses exceeding the maximum recommended dose.
When taken with SILENOR, the sedative effects of alcoholic beverages, sedating antihistamines, and other CNS depressants may be potentiated [s ee Warnings and Precautions (5.2) and Drug Interactions (7.3 , 7.4) ].
Patients should be cautioned about potential additive effects of SILENOR used in combination with CNS depressants or sedating antihistamines [s ee Warnings and Precautions (5.2) and Drug Interactions (7.4) ].
CNS Depressants and Sedating Antihistamines: Sedative effects may be increased with doxepin.
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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.