What the FDA labels say about taking them together
Clarithromycin and efavirenz
Clarithromycin's FDA label of April 9, 2026 names efavirenz in its drug interactions section, and efavirenz's label names clarithromycin too. The efavirenz label: “Consider alternatives to macrolide antibiotics because of the risk of QT interval prolongation.”
Check it at the source: the clarithromycin FDA label on DailyMed (effective April 9, 2026, Solaris Pharma Corporation); the efavirenz FDA label on DailyMed (effective March 31, 2024, Cipla USA Inc.).
What does the clarithromycin label say about efavirenz?
Clarithromycin label, drug interactionsEfavirenz Nevirapine Rifampicin Rifabutin Rifapentine; Use With Caution; Inducers of CYP3A enzymes, such as efavirenz, nevirapine, rifampicin, rifabutin, and rifapentine will increase the metabolism of clarithromycin, thus decreasing plasma concentrations of clarithromycin, while increasing those of 14-OH-clarithromycin. Since the microbiological activities of clarithromycin and 14-OH-clarithromycin are different for different bacteria, the intended therapeutic effect could be impaired during concomitant administration of clarithromycin and enzyme inducers. Alternative antibacterial treatment should be considered when treating patients receiving inducers of CYP3A. …
Source: FDA drug label (Clarithromycin), Solaris Pharma Corporation, effective April 9, 2026 (SPL set 4d42821d-ce7a-7d64-e063-6294a90a0875), via openFDA; the full label on DailyMed
What does the efavirenz label say about clarithromycin?
Efavirenz label, drug interactionsConcomitant Drug Class/Drug Name: Anti-infective: Clarithromycin; Effect: ↓ clarithromycin * ↑ 14-OH metabolite *; Clinical Comment: Consider alternatives to macrolide antibiotics because of the risk of QT interval prolongation.
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
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
| Clarithromycin | Efavirenz | |
|---|---|---|
| Labeled for | Bacterial infections, Acid reflux and ulcers | HIV |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.466 per tablet 500 mg tablet | $1.28 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