What the FDA labels say about taking them together
Nirmatrelvir/ritonavir and zidovudine
Nirmatrelvir/ritonavir's FDA label of February 19, 2026 names zidovudine in its drug interactions section; the zidovudine labels PlainMeds reads (3) do not name nirmatrelvir/ritonavir.
Check it at the source: the nirmatrelvir/ritonavir FDA label on DailyMed (effective February 19, 2026, Pfizer Laboratories Div Pfizer Inc); the zidovudine FDA label on DailyMed (effective February 10, 2025, Aurobindo Pharma Limited).
What does the nirmatrelvir/ritonavir label say about zidovudine?
Nirmatrelvir/ritonavir label, drug interactionsDrug Class: Anti-HIV; Drugs within Class: efavirenz, maraviroc, nevirapine, zidovudine, bictegravir/ emtricitabine/ tenofovir; Effect on Concentration: ↑ efavirenz ↑ maraviroc ↑ nevirapine ↓ zidovudine ↑ bictegravir ↔ emtricitabine ↑ tenofovir; Clinical Comments: For further information, refer to the respective anti-HIV drugs prescribing information.
Source: FDA drug label (Paxlovid), Pfizer Laboratories Div Pfizer Inc, effective February 19, 2026 (SPL set 8a99d6d6-fd9e-45bb-b1bf-48c7f761232a), via openFDA; the full label on DailyMed
What does the zidovudine label say about nirmatrelvir/ritonavir?
Zidovudine's label (effective February 10, 2025) and its 2 other brand-application labels do not name nirmatrelvir/ritonavir in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Zidovudine), Aurobindo Pharma Limited, effective February 10, 2025 (SPL set 51abd2ce-6be1-412d-b806-5f24935ac5e3), 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
| Nirmatrelvir/ritonavir | Zidovudine | |
|---|---|---|
| Labeled for | COVID-19 | HIV |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $49.24 per unit 300-100 mg dose pack | $0.464 per tablet 300 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