Skip to content


    DEA Class; Rx

    Common Brand Names; Lotronex

    • IBS Agents; 
    • Selective 5-HT3 Receptor Antagonists

    Oral selective serotonin 5-HT3 receptor antagonist
    Approved only for adult females with severe diarrhea-predominant IBS (IBS-D) failing conventional therapy

    Indicated for the treatment of severe, chronic, diarrhea-predominant irritable bowel syndrome (IBS) in women for whom conventional therapy has failed.

    Indicated only for women with severe diarrhea-predominant IBS who have: chronic IBS symptoms (generally lasting 6 months or longer), had anatomic or biochemical abnormalities of GI tract excluded, and not responded adequately to conventional therapy


    Rectal bleeding, history of chronic or severe current constipation

    History of ischemic colitis, intestinal obstruction, stricture, toxic megacolon, GI perforation or adhesion, thrombophlebitis, diverticulitis, hypercoagulable state, history of or current Crohn’s disease or ulcerative colitis

    Coadministration with apomorphine; combination reported to cause profound hypotension and loss of consciousness

    Inability to comply with the Patient-Physician Agreement for Lotronex

    Severe hepatic impairment

    Impaired intestinal circulation

    Concomitant administration with fluvoxamine


    • Constipation (29%)
    • Abdominal pain (7%)
    • Nausea (6%)
    • Headache (≥3%)
    • GI discomfort and pain (5%)
    • Fatigue (≥3%)
    • Gastroenteritis (>3%)
    • Abdominal distention (2%)
    • Flatulence (1-3%)
    • Regurgitation and reflux (2%)
    • Abdominal distension (2%)
    • Hemorrhoids (2%)
    • Urinary tract infection (≥3%)
    • Muscle spasm (≥3%)
    • Cough (≥3%)
    • Nasopharyngitis (≥3%)

    Discontinue if inadequate control after 4 weeks of q12hr dosing

    Use with caution in breast-feeding women

    Use caution in mild-to-moderate hepatic impairment

    Withdrawn from U.S. market in Nov. 2000 due to cases of severe ischemic colitis, obstructed or ruptured bowel, and death; reinstated in June 2002 on a limited basis

    The available data with use in pregnant women are insufficient to draw conclusions about any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes

    There are no data regarding presence of drug in human milk, effects on breastfed infant, or on milk production


    2 mg/day PO.


    2 mg/day PO.


    Safety and efficacy have not been established.


    Safety and efficacy have not been established.


    Safety and efficacy have not been established.


    Safety and efficacy have not been established.

    Alosetron hydrochloride


    • 0.5mg
    • 1mg