Possible Drugs for A Dominant Symptom in IBS
| Symptom | Drug | Dose |
|---|---|---|
| Diarrhea | Loperamide | 2-4 mg when necessary/maximum 12 g/d |
| Cholestyramine resin | 4 g with meals | |
| Alosetrona | 0.5-1 mg bid (for severe IBS, women) | |
| Constipation | Psyllium husk | 3-4 g bid with meals, then adjust |
| Methylcellulose | 2 g bid with meals, then adjust | |
| Calcium polycarbophil | 1 g qd to qid | |
| Lactulose syrup | 10-20 g bid | |
| 70% sorbitol | 15 mL bid | |
| Polyethylene glycol 3350 | 17 g in 250 mL water qd | |
| Lubiprostone (Amitiza) | 24 mg bid | |
| Magnesium hydroxide | 30-60 mL qd | |
| Abdominal pain | Smooth-muscle relaxant | qd to qid ac |
| Tricyclic antidepressants | Start 25-50 mg hs, then adjust | |
| Selective serotonin reuptake inhibitors | Begin small dose, increase as needed |
aAvailable only in the United States.
Abbreviation: IBS, irritable bowel syndrome.
Source: Adapted from Longstreth GF et al: Functional bowel disorders. Gastroenterology 130:1480, 2006.