What the FDA labels say about taking them together
Erythromycin and praziquantel
Praziquantel's FDA label of March 2, 2026 names erythromycin in its drug interactions section; the erythromycin labels PlainMeds reads (4) do not name praziquantel. The praziquantel label: “… (CYP450 inhibitors), for example, cimetidine, ketoconazole, itraconazole, erythromycin, and ritonavir may increase plasma concentrations of praziquantel.”
Check it at the source: the erythromycin FDA label on DailyMed (effective August 1, 2024, Teva Pharmaceuticals USA, Inc.); the praziquantel FDA label on DailyMed (effective March 2, 2026, Bayer HealthCare Pharmaceuticals Inc.).
What does the erythromycin label say about praziquantel?
Erythromycin's label (effective August 1, 2024) and its 3 other brand-application labels do 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 (Erythromycin), Teva Pharmaceuticals USA, Inc., effective August 1, 2024 (SPL set 75a0bd5a-d09f-483b-bfd8-f8343b149eb2), via openFDA; the full label on DailyMed
What does the praziquantel label say about erythromycin?
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
| Erythromycin | Praziquantel | |
|---|---|---|
| Labeled for | Bacterial infections, Acne | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $1.96 per tablet 250 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