Treatment	Initial dosage	Maintenance dosage	Cost (generic)*	Comments
Dicyclomine (Bentyl)	20 mg fourtimes per day	20 to 40 mg four times per day	$63 (22 to 82)	If not effective in two weeks, discontinue.
Hyoscyamine (Levsin)	0.125 to 0.250 mg every four hours	Same	145 (52 to 61)	Anticholinergic effects; maximum 1.5 gm per day
Loperamide (Imodium)	4 mg	4 to 8 mg per day	49 (15 to 42)	—
Amitriptyline	10 to 25 mg every night at bedtime	10 to 100 mg every night at bedtime	8 (2 to 10)	Large dosing range; start low, and titrate as needed.
Desipramine (Norpramin)	10 to 50 mg every night at bedtime	10 to 150 mg every night at bedtime	21 (12 to 21)	Large dosing range; start low, and titrate as needed.
Alosetron (Lotronex)	1 mg per day for four weeks	1 mg once or twice per day	216	Use in women with diarrheapredominant irritable bowel syndrome; use with caution; available only through prescribing program; associated with ischemic colitis.
Tegaserod (Zelnorm)	6 mg twice per day for four to 12 weeks	Same	169	Use in constipation with same caveats as alosetron; only indicated for 12 weeks of therapy.