What the FDA labels say about taking them together
Efavirenz/emtricitabine/tenofovir disoproxil and felodipine
Efavirenz/emtricitabine/tenofovir disoproxil's FDA label of July 28, 2025 names felodipine in its drug interactions section; the felodipine label PlainMeds reads does not name efavirenz/emtricitabine/tenofovir disoproxil. The efavirenz/emtricitabine/tenofovir disoproxil label: “No data are available on the potential interactions of EFV with other calcium channel blockers that are substrates of CYP3A. The potential exists for reduction in plasma concentrations of the calcium channel blocker. …”
Check it at the source: the efavirenz/emtricitabine/tenofovir disoproxil FDA label on DailyMed (effective July 28, 2025, Laurus Labs Limited); the felodipine FDA label on DailyMed (effective August 11, 2026, Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.).
What does the efavirenz/emtricitabine/tenofovir disoproxil label say about felodipine?
Efavirenz/emtricitabine/tenofovir disoproxil label, drug interactionsConcomitant Drug Class/Drug Name: Others e.g., felodipine nicardipine nifedipine verapamil; Effect: ↓ calcium channel blocker; Clinical Comment: No data are available on the potential interactions of EFV with other calcium channel blockers that are substrates of CYP3A. The potential exists for reduction in plasma concentrations of the calcium channel blocker. Dose adjustments should be guided by clinical response (refer to the full prescribing information for the calcium channel blocker).
Source: FDA drug label (Efavirenz, emtricitabine and tenofovir disoproxil fumarate), Laurus Labs Limited, effective July 28, 2025 (SPL set aca22076-f435-4533-9fcf-566b0734c313), via openFDA; the full label on DailyMed
What does the felodipine label say about efavirenz/emtricitabine/tenofovir disoproxil?
Felodipine's label (effective August 11, 2026) does not name efavirenz/emtricitabine/tenofovir disoproxil in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (FELODIPINE), Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc., effective August 11, 2026 (SPL set 0bef7cf2-012b-4804-ac93-0a8b333035db), 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/emtricitabine/tenofovir disoproxil | Felodipine | |
|---|---|---|
| Labeled for | HIV | High blood pressure |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $1.12 per tablet 600-200-300 mg tablet | $0.123 per tablet 5 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