FDA pharmacologic class
H2 blockers
4 medicines are in FDA's class of histamine-2 receptor antagonists (H2 blockers): famotidine (Pepcid), cimetidine (Tagamet), ranitidine and nizatidine; 2 combination products also contain one. All 6 are listed from generic labelers (FDA NDC Directory, October 8, 2026). The lowest pharmacy cost is famotidine 20 mg tablet at $0.0289 per tablet (NADAC).
Which medicines are h2 blockers?
| Medicine | Brand names | Generic labelers (all forms) | Pharmacy cost | Boxed warning | Shortage | Recalls since 2012 |
|---|---|---|---|---|---|---|
| Famotidine | Pepcid | 145 labelers | $0.0289 per tablet 20 mg tablet | No | No current entry | 14 |
| Calcium carbonate and famotidine and magnesium hydroxide | Pepcid, Dual | 20 labelers | $0.258 per tablet Acid reducer complete tablet chewable | No | No current entry | 0 |
| Cimetidine | Tagamet | 18 labelers | $0.236 per tablet 300 mg tablet | No | No current entry | 1 |
| Famotidine and ibuprofen | none listed | 16 labelers | $0.714 per unit 800-26.6 mg | Yes | No current entry | 1 |
| Ranitidine | none listed | 8 labelers | n/a | No | No current entry | 47 |
| Nizatidine | none listed | 4 labelers | $0.804 per capsule 150 mg capsule | No | No current entry | 3 |
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