Cannabidiol (prescription) and Tizanidine interaction
Cannabidiol (prescription) and Tizanidine: 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 Tizanidine (Zanaflex) label · effective 2026-01-02
Zanaflex is contraindicated in patients taking strong CYP1A2 inhibitors [see Drug Interactions ( 7.1 )] . with a history of hypersensitivity to tizanidine or the ingredients in Zanaflex.
Symptoms have included anaphylaxis and angioedema [see Warnings and Precautions ( 5.5 )] Concomitant use with strong CYP1A2 inhibitors ( 4 , 7.1 )
Therefore, concomitant use of Zanaflex with strong CYP1A2 inhibitors is contraindicated [see Contraindications ( 4 ) and Drug Interactions ( 7.1 )] .
Moderate or weak CYP1A2 inhibitors: avoid concomitant use; may cause hypotension, bradycardia, or excessive drowsiness; if concomitant use is necessary and adverse reactions occur, reduce Zanaflex dosage or discontinue.
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 )
From the Cannabidiol (prescription) (Epidiolex) label · effective 2026-05-29
Increases in exposure of certain CYP1A2 substrates (e.g., theophylline, tizanidine) may be observed when concomitantly used with EPIDIOLEX.
Other CNS depressants, including alcohol, could potentiate the somnolence and sedation effect of EPIDIOLEX.
CNS Depressants and Alcohol Concomitant use of EPIDIOLEX with other CNS depressants (including alcohol) may increase the risk of sedation and somnolence [see Warnings and Precautions ( 5.2 )] .
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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.