What the FDA labels say about taking them together
Paclitaxel and ritonavir
Paclitaxel's FDA label of January 21, 2026 names ritonavir in its drug interactions section; the ritonavir label PlainMeds reads does not name paclitaxel.
Check it at the source: the paclitaxel FDA label on DailyMed (effective January 21, 2026, Natco Pharma USA LLC); the ritonavir FDA label on DailyMed (effective July 23, 2026, AbbVie Inc.).
What does the paclitaxel label say about ritonavir?
Paclitaxel label, drug interactionsCaution should be exercised when paclitaxel is concomitantly administered with known substrates (eg, midazolam, buspirone, felodipine, lovastatin, eletriptan, sildenafil, simvastatin, and triazolam), inhibitors (eg, atazanavir, clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, ritonavir, saquinavir, and telithromycin), and inducers (eg, rifampin and carbamazepine) of CYP3A4. ( See CLINICAL PHARMACOLOGY section. ) Caution should also be exercised when paclitaxel is concomitantly administered with known substrates (eg, repaglinide and rosiglitazone), inhibitors (eg, gemfibrozil), and inducers (eg, rifampin) of CYP2C8. ( See CLINICAL PHARMACOLOGY. …
Source: FDA drug label (Paclitaxel), Natco Pharma USA LLC, effective January 21, 2026 (SPL set a1eb16b4-285b-4e81-9c4e-1244d4a52af8), via openFDA; the full label on DailyMed
What does the ritonavir label say about paclitaxel?
Ritonavir's label (effective July 23, 2026) does not name paclitaxel in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Norvir), AbbVie Inc., effective July 23, 2026 (SPL set 2849298e-de6e-47bb-8194-56e075b33fc3), 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
| Paclitaxel | Ritonavir | |
|---|---|---|
| Labeled for | Breast cancer, Lung cancer | HIV |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | n/a | $0.607 per tablet 100 mg tablet |
| Shortage now | No current entry | A presentation being discontinued |
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