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Table 149-2

Possible Drugs for A Dominant Symptom in IBS

SymptomDrugDose
DiarrheaLoperamide2-4 mg when necessary/maximum 12 g/d
Cholestyramine resin4 g with meals
Alosetrona0.5-1 mg bid (for severe IBS, women)
ConstipationPsyllium husk3-4 g bid with meals, then adjust
Methylcellulose2 g bid with meals, then adjust
Calcium polycarbophil1 g qd to qid
Lactulose syrup10-20 g bid
70% sorbitol15 mL bid
Polyethylene glycol 335017 g in 250 mL water qd
Lubiprostone (Amitiza)24 mg bid
Magnesium hydroxide30-60 mL qd
Abdominal painSmooth-muscle relaxantqd to qid ac
Tricyclic antidepressantsStart 25-50 mg hs, then adjust
Selective serotonin reuptake inhibitorsBegin 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.