Doxepin and Tizanidine interaction
Doxepin and Tizanidine: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
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.
From the Tizanidine (Zanaflex) label · effective 2026-01-02
Sedation: Zanaflex may interfere with everyday activities; sedative effects of Zanaflex, alcohol, and other central nervous system (CNS) depressants are additive ( 5.3 , 7.4 )
The CNS depressant effects of Zanaflex with alcohol and other CNS depressants (e.g., benzodiazepines, opioids, tricyclic antidepressants) may be additive [see Drug Interactions ( 7.4 )] .
Monitor patients who take Zanaflex with another CNS depressant for symptoms of excess sedation.
Alcohol and Other CNS Depressants Alcohol increases the exposure of tizanidine after administration of Zanaflex.
Concomitant use of Zanaflex with CNS depressants (e.g., alcohol, benzodiazepines, opioids, tricyclic antidepressants) may cause additive CNS depressant effects, including sedation.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.