FDA pharmacologic class
Antihistamines (H1 blockers)
11 medicines are in FDA's class of histamine-1 receptor antagonists (antihistamines): diphenhydramine, cetirizine (All), fexofenadine (Allegra), olopatadine (Pataday), levocetirizine (Xyzal), chlorpheniramine, azelastine (Astepro), desloratadine (Clarinex) and 3 more; 11 combination products also contain one. 17 of the 22 are listed from generic labelers (FDA NDC Directory, October 8, 2026). The lowest pharmacy cost is allergy 4 mg tablet at $0.0177 per tablet (NADAC).
Which medicines are antihistamines?
| Medicine | Brand names | Generic labelers (all forms) | Pharmacy cost | Boxed warning | Shortage | Recalls since 2012 |
|---|---|---|---|---|---|---|
| Diphenhydramine | none listed | 20 labelers | $0.898 per mL 50 mg/mL vial | No | No current entry | 8 |
| Cetirizine | Zyrtec, All, Quzyttir | 149 labelers | $0.0613 per tablet 10 mg tablet | No | No current entry | 19 |
| Fexofenadine | Allegra | 101 labelers | $0.230 per tablet 180 mg tablet | No | No current entry | 21 |
| Olopatadine | Pataday | 47 labelers | $2.96 per mL 0.2% eye drop | No | No current entry | 6 |
| Levocetirizine | Xyzal | 53 labelers | $0.0511 per tablet 5 mg tablet | No | No current entry | 1 |
| Diphenhydramine and ibuprofen | Advil | 39 labelers | $0.131 per unit Gs ibuprofen pm caplet | No | No current entry | 1 |
| Fexofenadine and pseudoephedrine | Allegra-D | 26 labelers | $0.483 per tablet 60-120 tablet | No | No current entry | 5 |
| Chlorpheniramine | none listed | 2 labelers | $0.0177 per tablet 4 mg tablet | No | No current entry | 0 |
| Cetirizine and pseudoephedrine | Zyrtec-D | 24 labelers | $0.563 per tablet 5-120 mg tablet | No | No current entry | 0 |
| Azelastine | Astepro | 22 labelers | $0.273 per mL 0.1% (137 mcg) spry | No | No current entry | 3 |
| Diphenhydramine and naproxen | Aleve | 17 labelers | n/a | No | No current entry | 0 |
| Desloratadine | Clarinex | 9 labelers | $0.258 per tablet 5 mg tablet | No | No current entry | 1 |
| Carbinoxamine | Karbinal, Ryvent, Carbzah | 7 labelers | $0.398 per tablet 4 mg tablet | No | No current entry | 0 |
| Bepotastine | Bepreve | 4 labelers | $9.39 per mL 1.5% eye drop | No | No current entry | 0 |
| Azelastine and fluticasone | Dymista | 4 labelers | $2.02 per gram 137-50 mcg spr | No | No current entry | 2 |
| Alcaftadine | Lastacaft | 3 labelers | $2.83 per mL 0.25% drp | No | No current entry | 0 |
| Chlorpheniramine and ibuprofen and phenylephrine | Advil | none listed | n/a | No | No current entry | 1 |
| Chlorpheniramine and hydrocodone | none listed | 2 labelers | $0.556 per mL Hydrocodone-chlorphen ER suspension | Yes | No current entry | 1 |
| Mometasone and olopatadine | Ryaltris | none listed | $7.67 per gram 665-25 mcg spray | No | No current entry | 1 |
| Chlorpheniramine and codeine | Tuxarin | none listed | n/a | Yes | No current entry | 0 |
| Chlorpheniramine and ibuprofen and pseudoephedrine | Advil | none listed | n/a | No | No current entry | 0 |
| Desloratadine and pseudoephedrine | Clarinex-D | none listed | $6.07 per tablet 12 hr 2.5-120 mg tablet | 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