Praziquantel and Rifampin interaction
Praziquantel and Rifampin: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Praziquantel (Biltricide) label · effective 2026-03-02
• Patients taking strong Cytochrome P450 3A enzyme (CYP3A) inducers, such as rifampin, [see Warnings and Precautions ( 5.6 ) and Drug Interactions ( 7.1 , 7.2 )] .
• Concomitant administration with strong Cytochrome P450 3A enzyme (CYP 3A) inducers such as rifampin.
Moderate 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 )] .
Moderate CYP 3A Inducers : Avoid concomitant administration of moderate CYP 3A inducers, for example, efavirenz ( 5.6 , 7.1 )
Concomitant administration of a Strong CYP 3A inducer, such as rifampin, with Biltricide is contraindicated [see Contraindications ( 4)] .
From the Rifampin label · effective 2026-05-05
(See PRECAUTIONS, Drug Interactions .) Rifampin is contraindicated in patients receiving praziquantel since therapeutically effective blood levels of praziquantel may not be achieved.
In patients receiving rifampin who need immediate treatment with praziquantel alternative agents should be considered.
However, if treatment with praziquantel is necessary, rifampin should be discontinued 4 weeks before administration of praziquantel.
Treatment with rifampin can then be restarted one day after completion of praziquantel treatment.
Praziquantel Prevention or Management: Concomitant use is contraindicated (see CONTRAINDICATIONS ) Decrease plasma praziquantel concentrations to undetectable levels.
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.