FDA pharmacologic class
Histamine-1 Receptor Inhibitor
3 medicines are in FDA's class of histamine-1 receptor inhibitors: olopatadine (Pataday), ketotifen (Eye) and epinastine; 1 combination product also contains one. 3 of the 4 are listed from generic labelers (FDA NDC Directory, October 8, 2026). The lowest pharmacy cost is ketotifen 0.025% (0.035%) drop at $1.29 per mL (NADAC).
Which medicines are histamine-1 receptor inhibitor?
| Medicine | Brand names | Generic labelers (all forms) | Pharmacy cost | Boxed warning | Shortage | Recalls since 2012 |
|---|---|---|---|---|---|---|
| Olopatadine | Pataday | 47 labelers | $2.96 per mL 0.2% eye drop | No | No current entry | 6 |
| Ketotifen | Eye, Alaway, Equate | 7 labelers | $1.29 per mL 0.025% (0.035%) drop | No | No current entry | 1 |
| Mometasone and olopatadine | Ryaltris | none listed | $7.67 per gram 665-25 mcg spray | No | No current entry | 1 |
| Epinastine | none listed | 1 labeler | $14.33 per mL 0.05% eye drops | No | No current entry | 0 |
Source: FDA Established Pharmacologic Class (NDC Directory, openFDA); CMS NADAC of October 7, 2026; FDA shortages and recalls (FDA files October 8, 2026)
What do pharmacies pay?
Each medicine's most widely listed form, per unit, in the NADAC survey: what pharmacies paid, not what a patient pays; strengths differ, so compare like with like.
Source: CMS National Average Drug Acquisition Cost (NADAC) survey, October 7, 2026: what retail pharmacies paid per unit; not a counter price