What the FDA labels say about taking them together
Cilostazol and nirmatrelvir/ritonavir
Nirmatrelvir/ritonavir's FDA label of February 19, 2026 names cilostazol in its drug interactions section; the cilostazol label PlainMeds reads does not name nirmatrelvir/ritonavir. The nirmatrelvir/ritonavir label: “Drug Class: cilostazol; Drugs within Class: ↑ cilostazol; Effect on Concentration: Dosage adjustment of cilostazol is recommended. Refer to the cilostazol prescribing information for more information.”
Check it at the source: the cilostazol FDA label on DailyMed (effective September 10, 2026, Apotex Corp.); the nirmatrelvir/ritonavir FDA label on DailyMed (effective February 19, 2026, Pfizer Laboratories Div Pfizer Inc).
What does the cilostazol label say about nirmatrelvir/ritonavir?
Cilostazol's label (effective September 10, 2026) does 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 (cilostazol), Apotex Corp., effective September 10, 2026 (SPL set ceac1ae3-c343-28ca-c083-b748d21a15e6), via openFDA; the full label on DailyMed
What does the nirmatrelvir/ritonavir label say about cilostazol?
Nirmatrelvir/ritonavir label, drug interactionsDrug Class: cilostazol; Drugs within Class: ↑ cilostazol; Effect on Concentration: Dosage adjustment of cilostazol is recommended. Refer to the cilostazol prescribing information for more 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
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
| Cilostazol | Nirmatrelvir/ritonavir | |
|---|---|---|
| Labeled for | n/a | COVID-19 |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.132 per tablet 100 mg tablet | $49.24 per unit 300-100 mg dose pack |
| 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