What the FDA labels say about taking them together
Cimetidine and praziquantel
Praziquantel's FDA label of March 2, 2026 names cimetidine in its drug interactions section; the cimetidine label PlainMeds reads does not name praziquantel. The praziquantel label: “CYP450 inhibitors Concomitant administration of drugs that decrease the activity of drug metabolizing liver enzymes (CYP450 inhibitors), for example, cimetidine, ketoconazole, itraconazole, erythromycin, and ritonavir …”
Check it at the source: the cimetidine FDA label on DailyMed (effective July 15, 2026, Mylan Pharmaceuticals Inc.); the praziquantel FDA label on DailyMed (effective March 2, 2026, Bayer HealthCare Pharmaceuticals Inc.).
What does the cimetidine label say about praziquantel?
Cimetidine's label (effective July 15, 2026) does not name praziquantel in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Cimetidine), Mylan Pharmaceuticals Inc., effective July 15, 2026 (SPL set 06c0a509-026f-44e0-9975-a94a8de51d43), via openFDA; the full label on DailyMed
What does the praziquantel label say about cimetidine?
Praziquantel label, drug interactionsCYP450 inhibitors Concomitant administration of drugs that decrease the activity of drug metabolizing liver enzymes (CYP450 inhibitors), for example, cimetidine, ketoconazole, itraconazole, erythromycin, and ritonavir may increase plasma concentrations of praziquantel.
Source: FDA drug label (Biltricide), Bayer HealthCare Pharmaceuticals Inc., effective March 2, 2026 (SPL set 34ce1cdd-648e-4f1e-8512-bf3d4cc22eb9), 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
| Cimetidine | Praziquantel | |
|---|---|---|
| Labeled for | Acid reflux and ulcers | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.236 per tablet 300 mg tablet | $53.25 per tablet 600 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