What the FDA labels say about taking them together
Levocetirizine and ritonavir
Levocetirizine's FDA label of March 11, 2026 names ritonavir in its drug interactions (prescription label) section; the ritonavir label PlainMeds reads does not name levocetirizine. The levocetirizine label: “Ritonavir increased the plasma AUC of cetirizine by about 42% accompanied by an increase in half-life (53%) and a decrease in clearance (29%) of cetirizine.”
Check it at the source: the levocetirizine FDA label on DailyMed (effective March 11, 2026, Chattem, Inc.); the ritonavir FDA label on DailyMed (effective July 23, 2026, AbbVie Inc.).
What does the levocetirizine label say about ritonavir?
Levocetirizine label, drug interactions (prescription label)Ritonavir increased the plasma AUC of cetirizine by about 42% accompanied by an increase in half-life (53%) and a decrease in clearance (29%) of cetirizine.
Source: FDA drug label (Xyzal Allergy 24HR), Chattem, Inc., effective March 11, 2026 (SPL set 8be45c2a-1eca-4a00-81b9-f7babdbdcd41), via openFDA; the full label on DailyMed
What does the ritonavir label say about levocetirizine?
Ritonavir's label (effective July 23, 2026) does not name levocetirizine 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
| Levocetirizine | Ritonavir | |
|---|---|---|
| Labeled for | Allergies | HIV |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.0511 per tablet 5 mg tablet | $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