What the FDA labels say about taking them together
Ciprofloxacin and tizanidine
Ciprofloxacin's FDA label of March 2, 2026 names tizanidine in its contraindications section, and tizanidine's label names ciprofloxacin too. The ciprofloxacin label: “Concomitant administration with tizanidine is contraindicated.”
Check it at the source: the ciprofloxacin FDA label on DailyMed (effective March 2, 2026, Bayer HealthCare Pharmaceuticals Inc.); the tizanidine FDA label on DailyMed (effective January 2, 2026, Legacy Pharma USA, Inc.).
What does the ciprofloxacin label say about tizanidine?
Ciprofloxacin label, contraindicationsConcomitant administration with tizanidine is contraindicated [see Drug Interactions ( 7 )].
Ciprofloxacin label, drug interactionsTizanidine; Contraindicated; Concomitant administration of tizanidine and CIPRO is contraindicated due to the potentiation of hypotensive and sedative effects of tizanidine [ see Contraindications () ]
Ciprofloxacin label, warnings and precautionsCo-administration of CIPRO and other drugs primarily metabolized by CYP1A2 (for example, theophylline, methylxanthines, caffeine, tizanidine, ropinirole, clozapine, olanzapine and zolpidem), results in increased plasma concentrations of the co-administered drug and could lead to clinically significant pharmacodynamic adverse reactions of the co-administered drug [see Drug Interactions ( 7 ) and Clinical Pharmacology ( 12.3 )].
Source: FDA drug label (Cipro), Bayer HealthCare Pharmaceuticals Inc., effective March 2, 2026 (SPL set 888dc7f9-ad9c-4c00-8d50-8ddfd9bd27c0), via openFDA; the full label on DailyMed
What does the tizanidine label say about ciprofloxacin?
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 interactionsChanges in pharmacokinetics of tizanidine when administered with fluvoxamine resulted in significantly decreased blood pressure, increased drowsiness, and increased psychomotor impairment [see Contraindications ( 4 ) and Clinical Pharmacology ( 12.3 )]. Concomitant use of ciprofloxacin 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
| Ciprofloxacin | Tizanidine | |
|---|---|---|
| Labeled for | Diarrhea, Urinary tract infections, Bacterial infections | Muscle spasms and spasticity |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.123 per tablet 500 mg tablet | $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