III. Contraindications

  1. History of Ischemic Colitis (including from Alosetron)
  2. Fluvoxamine concurrent use (CYP1A2 Inhibitor)
  3. Constipation
  4. Crohns Disease
  5. Intestinal Obstruction
  6. Severe liver disease

IV. Precautions

  1. FDA Black box warning
    1. Deaths have occurred due to Ischemic Colitis
    2. Requires signed Informed Consent before prescribing

V. Mechanism

  1. Potent, selective 5-HT3 Receptor Antagonist
  2. Blocks Serotonin at 5-HT3 receptors throughout Peripheral Nervous System including the Gastrointestinal System
  3. Effects (similar to Ondansetron)
    1. Decreases gastrointestinal motility (decreases rapid transit and stool urgency)
    2. Decreases gastrointestinal secretions

VI. Dosing

  1. Start 0.5 mg orally twice daily for 4 weeks
  2. Next: Increase to 1 mg orally twice daily if tolerated

VII. Adverse Effects

  1. Common
    1. Abdominal Pain
    2. Nausea
    3. Constipation
  2. Serious
    1. Ischemic Colitis (deaths have occurred)

VIII. Safety

  1. Pregnancy Category B
  2. Unknown safety in Lactation

XI. References

  1. (2021) Irritable Bowel Syndrome Drug Comparison, Presc Lett, #370305
  2. (2020) Med Lett Drugs Ther 62(1594): 41-58

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Related Studies

Cost: Medications

alosetron (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
ALOSETRON HCL 0.5 MG TABLET Generic $4.67 each
ALOSETRON HCL 1 MG TABLET Generic $6.20 each

Ontology: alosetron (C0291772)

Definition (NCI) A potent and selective 5-HT3 receptor antagonist. Alosetron blocks the actions of serotonin at 5-HT3 sites in the peripheral nervous system, particularly on enteric and nociceptive sensory neurons, thereby affecting the regulation of visceral pain, decreasing gastrointestinal contraction and motility, and decreasing gastrointestinal secretions. This agent is used to treat diarrhea-predominant irritable bowel syndrome in women.
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH C090840
SnomedCT 116509006, 409148009
English alosetron, alosetron [Chemical/Ingredient], Alosetron (substance), Alosetron, Alosetron (product), ALOSETRON
Spanish alosetrona, alosetrón, alosetrón (sustancia), alosetrona (sustancia), alosetrón (producto), alosetrona (producto)