| Aluminum hydroxide/magnesium hydroxide (Maalox)* | B | Antacid | Not known | Generally regarded as safe |
| Calcium carbonate (Tums) | C | Antacid | Not known | Generally regarded as safe |
| Simethicone (Mylanta Gas) | C | Antiflatulent | No | Generally regarded as safe |
| Cimetidine (Tagamet) | B | Antihistamine | Yes | Preferred after antacids; generally regarded as safe |
| Ranitidine (Zantac) | B | Antihistamine | Yes | Preferred after antacids; generally regarded as safe |
| Nizatidine (Axid) | C | Antihistamine | Yes | Not recommended (adverse animal studies) |
| Famotidine (Pepcid) | B | Antihistamine | Yes | Probably safe, data needed |