Tizanidine and Trifluoperazine interaction
Tizanidine and Trifluoperazine: 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 Trifluoperazine (Trifluoperazine Hydrochloride) label · effective 2026-01-30
CONTRAINDICATIONS A known hypersensitivity to phenothiazines, comatose or greatly depressed states due to central nervous system depressants and, in cases of existing blood dyscrasias, bone marrow depression and preexisting liver damage.
Antihypertensive effects of guanethidine and related compounds may be counteracted when phenothiazines are used concurrently.
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.