Pretomanid and Nafcillin Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Pretomanid
No brand names on recordNafcillin Injection
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Decreased plasma levels of pretomanid
Interaction Deep Dive
Coadministration of pretomanid with the CYP3A4 inducers rifampin or efavirenz resulted in a decrease in pretomanid AUC and Cmax. Avoid coadministration of pretomanid with strong or moderate CYP3A4 inducers1,
Why it happens (mechanism)
Induction of CYP3A4-mediated metabolism of pretomanid
Literature reports
2 reports — tap to read
a) Coadministration of pretomanid 200 mg orally once daily with the moderate CYP3A4 inducer efavirenz 600 mg once daily for 7 days resulted in a decrease of mean pretomanid AUC by 35% and Cmax by 28% 1.
b) Coadministration of pretomanid 200 mg orally once daily with the strong CYP3A4 inducer rifampin 600 mg once for 7 days resulted in a decrease of mean pretomanid AUC by 66% and Cmax by 53% 1.
Common questions
Can I take Pretomanid and Nafcillin Injection together?
Decreased plasma levels of pretomanid Always confirm with your pharmacist or prescriber before making any change.
How serious is the Pretomanid and Nafcillin Injection interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Pretomanid or Nafcillin Injection need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: Pretomanid oral tablets, pretomanid oral tablets. TB Alliance (per manufacturer), New York, NY, 2019. DailyMed
Keep reading about Pretomanid
Keep reading about Nafcillin Injection
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