Modafinil and Tizanidine interaction
Modafinil 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
Hypotension: monitor for signs and symptoms of hypotension, in particular in patients receiving concurrent antihypertensives; Zanaflex should not be used with other α 2 -adrenergic agonists ( 5.1 , 7.7 )
It is not recommended that Zanaflex be used with other α 2 -adrenergic agonists.
α 2 -Adrenergic Agonists Concomitant use of Zanaflex with other α2-adrenergic agonists is not recommended because hypotensive effects may be cumulative [see Warnings and Precautions ( 5.1 )] .
Hypotension Zanaflex is an α 2 -adrenergic agonist that can produce hypotension [see Adverse Reactions ( 6.1 ) and Drug Interactions ( 7.5 )] .
From the Modafinil (Provigil) label · effective 2025-10-16
However, a retrospective analysis of the use of antihypertensive medication in these studies showed that a greater proportion of patients on PROVIGIL required new or increased use of antihypertensive medications (2.4%) compared to patients on placebo (0.7%).
The differential use was slightly larger when only studies in OSA were included, with 3.4% of patients on PROVIGIL and 1.1% of patients on placebo requiring such alterations in the use of antihypertensive medication.
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.