What the FDA labels say about taking them together
Efavirenz and praziquantel
Efavirenz's FDA label of March 31, 2024 names praziquantel in its drug interactions section, and praziquantel's label names efavirenz too. The efavirenz label: “Coadministration with efavirenz is not recommended due to significant decrease in plasma concentrations of praziquantel, with risk of treatment failure due to increased hepatic metabolism by efavirenz.”
Check it at the source: the efavirenz FDA label on DailyMed (effective March 31, 2024, Cipla USA Inc.); the praziquantel FDA label on DailyMed (effective March 2, 2026, Bayer HealthCare Pharmaceuticals Inc.).
What does the efavirenz label say about praziquantel?
Efavirenz label, drug interactionsConcomitant Drug Class/Drug Name: Anthelmintic: Praziquantel; Effect: ↓ praziquantel; Clinical Comment: Coadministration with efavirenz is not recommended due to significant decrease in plasma concentrations of praziquantel, with risk of treatment failure due to increased hepatic metabolism by efavirenz.
Source: FDA drug label (Efavirenz), Cipla USA Inc., effective March 31, 2024 (SPL set 92603fa5-7a2c-4bfb-9a70-aadb4fba952c), via openFDA; the full label on DailyMed
What does the praziquantel label say about efavirenz?
Praziquantel label, drug interactionsDRUG INTERACTIONS Moderate CYP 3A Inducers: Avoid concomitant administration of moderate CYP 3A inducers, for example, efavirenz
Praziquantel label, warnings and precautionsModerate CYP 3A Inducers Avoid concomitant administration of Biltricide with moderate CYP 3A inducers, such as efavirenz, due to risk of a clinically significant decrease in praziquantel plasma concentrations which may lead to reduced therapeutic effect of Biltricide [see Drug Interactions ( 7.1 )].
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
| Efavirenz | Praziquantel | |
|---|---|---|
| Labeled for | HIV | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $1.28 per tablet 600 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