What the FDA labels say about taking them together
Clozapine and nirmatrelvir/ritonavir
Nirmatrelvir/ritonavir's FDA label of February 19, 2026 names clozapine in its drug interactions section; the clozapine labels PlainMeds reads (2) do not name nirmatrelvir/ritonavir. The nirmatrelvir/ritonavir label: “Drug Class: clozapine; Drugs within Class: ↑ clozapine; Effect on Concentration: If co-administration is necessary, consider reducing the clozapine dose and monitor for adverse reactions.”
Check it at the source: the clozapine FDA label on DailyMed (effective June 6, 2025, HLS Therapeutics (USA), Inc.); the nirmatrelvir/ritonavir FDA label on DailyMed (effective February 19, 2026, Pfizer Laboratories Div Pfizer Inc).
What does the clozapine label say about nirmatrelvir/ritonavir?
Clozapine's label (effective June 6, 2025) and its 1 other brand-application label 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 (Clozaril), NDA019758 (Heritage Life), as published by HLS Therapeutics (USA), Inc., effective June 6, 2025 (SPL set 90876802-0e3a-44c9-9ff7-1754dfbe736a), via openFDA; the full label on DailyMed
What does the nirmatrelvir/ritonavir label say about clozapine?
Nirmatrelvir/ritonavir label, drug interactionsDrug Class: clozapine; Drugs within Class: ↑ clozapine; Effect on Concentration: If co-administration is necessary, consider reducing the clozapine dose and monitor for adverse reactions.
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
| Clozapine | Nirmatrelvir/ritonavir | |
|---|---|---|
| Labeled for | Schizophrenia | COVID-19 |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.610 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