What the FDA labels say about taking them together
Tizanidine and verapamil
Tizanidine's FDA label of January 2, 2026 names verapamil in its drug interactions section; the verapamil labels PlainMeds reads (4) do not name tizanidine. The tizanidine label: “Inhibitors other than Fluvoxamine and Ciprofloxacin Because of potential drug interactions, concomitant use of Zanaflex with other CYP1A2 inhibitors, such as zileuton, fluoroquinolones other than strong CYP1A2 …”
Check it at the source: the tizanidine FDA label on DailyMed (effective January 2, 2026, Legacy Pharma USA, Inc.); the verapamil FDA label on DailyMed (effective April 6, 2026, Zydus Pharmaceuticals (USA) Inc.).
What does the tizanidine label say about verapamil?
Tizanidine label, drug interactionsConcomitant use of Zanaflex with moderate or weak CYP1A2 inhibitors (e.g., zileuton, antiarrhythmics [amiodarone, mexiletine, propafenone, and verapamil], cimetidine, famotidine, oral contraceptives, acyclovir, and ticlopidine) should be avoided.
Zanaflex label (Covis Pharma US, Inc, May 5, 2025), drug interactionsInhibitors other than Fluvoxamine and Ciprofloxacin Because of potential drug interactions, concomitant use of Zanaflex with other CYP1A2 inhibitors, such as zileuton, fluoroquinolones other than strong CYP1A2 inhibitors (which are contraindicated), antiarrhythmics (amiodarone, mexiletine, propafenone, and verapamil), cimetidine, famotidine, oral contraceptives, acyclovir, and ticlopidine) should be avoided.
Ontralfy label (Rosemont Pharmaceuticals, LLC, October 25, 2025), drug interactionsConcomitant use of Ontralfy with moderate or weak CYP1A2 inhibitors (e.g., zileuton, antiarrhythmics [amiodarone, mexiletine, propafenone, and verapamil], cimetidine, famotidine, oral contraceptives, acyclovir, and ticlopidine) should be avoided.
Source: FDA drug label (Zanaflex, NDA020397), Covis Pharma US, Inc, effective May 5, 2025 (SPL set 043d9e51-bfa2-4add-9058-5ece332f7e99), via openFDA
Source: FDA drug label (Ontralfy, NDA216190), Rosemont Pharmaceuticals, LLC, effective October 25, 2025 (SPL set 7b88c338-c0b7-4c08-bef6-a4ffc2f25df7), via openFDA
Source: FDA drug label (Zanaflex), Legacy Pharma USA, Inc., effective January 2, 2026 (SPL set 60c27d35-7349-4fc6-86ad-70fffdbe3e08), via openFDA; the full label on DailyMed
What does the verapamil label say about tizanidine?
Verapamil's label (effective April 6, 2026) and its 3 other brand-application labels do not name tizanidine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Verapamil hydrochloride), Zydus Pharmaceuticals (USA) Inc., effective April 6, 2026 (SPL set e19ab8d8-dae5-489d-9805-7e7407bea06d), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Tizanidine | Verapamil | |
|---|---|---|
| Labeled for | Muscle spasms and spasticity | High blood pressure, Atrial fibrillation, Angina |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.0331 per tablet 4 mg tablet | $0.191 per tablet 180 mg tablet |
| Shortage now | No current entry | A presentation being discontinued |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once