What the FDA labels say about taking them together
Fluvoxamine and tizanidine
Fluvoxamine's FDA label of June 27, 2026 names tizanidine in its contraindications section, and tizanidine's label names fluvoxamine too. The tizanidine label: “DRUG INTERACTIONS 7.1 Fluvoxamine Concomitant use of fluvoxamine and Zanaflex is contraindicated.”
Check it at the source: the fluvoxamine FDA label on DailyMed (effective June 27, 2026, Zydus Pharmaceuticals USA Inc.); the tizanidine FDA label on DailyMed (effective January 2, 2026, Legacy Pharma USA, Inc.).
What does the fluvoxamine label say about tizanidine?
Fluvoxamine label, contraindicationsCONTRAINDICATIONS Coadministration of thioridazine, tizanidine, pimozide, alosetron, or ramelteon with fluvoxamine maleate extended-release capsules is contraindicated (see Warnings and Precautions [ 5.4 to 5.8 ] ).
Fluvoxamine label, drug interactionsCYP1A2 (e.g., warfarin, theophylline, propranolol, tizanidine), CYP2C9 (e.g., warfarin), CYP3A4 (e.g., alprazolam), and CYP2C19 (e.g., omeprazole).
Fluvoxamine label, warnings and precautionsFluvoxamine is a potent inhibitor of CYP1A2, and tizanidine is a CYP1A2 substrate.
Fluvoxamine Maleate label (ANI Pharmaceuticals, Inc., August 4, 2025), contraindicationsCONTRAINDICATIONS Coadministration Coadministration of tizanidine, thioridazine, alosetron, or pimozide with Fluvoxamine Maleate Tablets is contraindicated [see Warnings and Precautions ( 5.4 , 5.5 , 5.6 , 5.7 )].
Source: FDA drug label (Fluvoxamine Maleate, NDA021519), ANI Pharmaceuticals, Inc., effective August 4, 2025 (SPL set 7ecd83ec-88f5-4f85-9cc2-9068375d8820), via openFDA
Source: FDA drug label (Fluvoxamine maleate extended-release), Zydus Pharmaceuticals USA Inc., effective June 27, 2026 (SPL set 6c71d4f6-54b5-4d3a-8d2f-b7773c92c32e), via openFDA; the full label on DailyMed
What does the tizanidine label say about fluvoxamine?
Tizanidine label, drug interactionsConcomitant use of Zanaflex with strong cytochrome P450 1A2 (CYP1A2) inhibitors (e.g., fluvoxamine, ciprofloxacin) is contraindicated.
Zanaflex label (Covis Pharma US, Inc, May 5, 2025), contraindicationsCONTRAINDICATIONS Zanaflex is contraindicated in patients taking potent inhibitors of CYP1A2, such as fluvoxamine or ciprofloxacin [see Drug Interactions ( 7.1 , 7.2 )].
Zanaflex label (Covis Pharma US, Inc, May 5, 2025), drug interactionsDRUG INTERACTIONS 7.1 Fluvoxamine Concomitant use of fluvoxamine and Zanaflex is contraindicated.
Zanaflex label (Covis Pharma US, Inc, May 5, 2025), warnings and precautionsClinically significant hypotension (decreases in both systolic and diastolic pressure) has been reported with concomitant administration of either fluvoxamine or ciprofloxacin and single doses of 4 mg of Zanaflex.
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 (Zanaflex), Legacy Pharma USA, Inc., effective January 2, 2026 (SPL set 60c27d35-7349-4fc6-86ad-70fffdbe3e08), 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
| Fluvoxamine | Tizanidine | |
|---|---|---|
| Labeled for | n/a | Muscle spasms and spasticity |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $4.08 per capsule 100 mg capsule | $0.0331 per tablet 4 mg tablet |
| Shortage now | No current entry | No current entry |
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