Skip to Content

Alosetron Side Effects

In Summary

Commonly reported side effects of alosetron include: constipation. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to alosetron: oral tablet

Along with its needed effects, alosetron may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking alosetron:

More common Rare Incidence not known

Get emergency help immediately if any of the following symptoms of overdose occur while taking alosetron:

Symptoms of overdose
  • Clumsiness, unsteadiness, trembling, or other problems with muscle control or coordination
  • convulsions (seizures)
  • difficulty breathing
  • shakiness and unsteady walk
  • withdrawn or socially detached behavior

Some side effects of alosetron may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common
  • Bleeding after bowel movement
  • full or bloated feeling
  • pressure in the stomach
  • swelling of abdominal or stomach area
  • uncomfortable swelling around rectal area
Incidence not known

For Healthcare Professionals

Applies to alosetron: oral tablet


The most commonly reported side effects included constipation, abdominal discomfort/pain, diarrhea, and nausea.[Ref]


Very common (10% or more): Constipation (up to 75%)
Common (1% to 10%): Abdominal discomfort, abdominal distention, abdominal pain, abdominal pain upper, diarrhea, flatulence, gastrointestinal discomfort, gastrointestinal pain, hemorrhoid hemorrhage, hemorrhoids, nausea, reflux, regurgitation, viral gastroenteritis, vomiting
Uncommon (0.1% to 1%): Dyspeptic symptoms, gastrointestinal lesions, gastrointestinal spasms, hyposalivation, ischemic colitis
Rare (0.01% to 0.1%): Abnormal tenderness, colitis, decreased gastric motility, diverticulitis, gastritis, gastroduodenitis, gastroenteritis, gastrointestinal intussusception, gastrointestinal obstruction, gastrointestinal signs/symptoms, hyperacidity, ileus, oral symptoms, positive fecal occult blood, proctitis, ulcerative colitis
Frequency not reported: Complications of colitis
Postmarketing reports: Impaction, perforation, small bowel mesenteric ischemia, ulceration[Ref]


Common (1% to 10%): Cough, nasopharyngitis, sinusitis, upper respiratory tract infection
Uncommon (0.1% to 1%): Breathing disorders
Rare (0.01% to 0.1%): Laryngitis, nose infection, throat infection, viral nose infection, viral throat infection[Ref]


Common (1% to 10%): Urinary tract infection
Uncommon (0.1% to 1%): Urinary frequency
Rare (0.01% to 0.1%): Bladder inflammation, diuresis, female reproductive tract bleeding/hemorrhage, polyuria, sexual function disorders, urinary tract hemorrhage[Ref]


Common (1% to 10%): ALT elevation
Rare (0.01% to 0.1%): Abnormal bilirubin levels, cholecystitis
Frequency not reported: Elevated alkaline phosphatase, elevated AST, elevated bilirubin, hepatitis without jaundice[Ref]


Uncommon (0.1% to 1%): Fatigue, malaise, pain, temperature regulation disturbances
Rare (0.01% to 0.1%): Cold sensation, ear infections, hot and cold sensations, viral ear infections[Ref]


Uncommon (0.1% to 1%): Sweating, urticaria
Rare (0.01% to 0.1%): Acne, allergic skin reaction, alopecia, dermatitis, dermatosis, eczema, folliculitis, hair loss, nail disorders, sebum disorders, skin infections, sweat disorders
Postmarketing reports: Rash[Ref]

Nervous system

Uncommon (0.1% to 1%): Hypnagogic effects
Rare (0.01% to 0.1%): Burning sensations, cognitive function disorder, equilibrium disorders, hypoesthesia, memory effects, sedation, taste disturbance, tremors
Frequency not reported: Headache[Ref]


Uncommon (0.1% to 1%): Cramps
Rare (0.01% to 0.1%): Bone pain, muscle pain, muscle stiffness, rigidity, skeletal pain, tightness
Frequency not reported: Muscle spasms[Ref]


Uncommon (0.1% to 1%): Tachyarrhythmias
Rare (0.01% to 0.1%): Arrhythmias, contusions, extrasystoles, hematoma, hemorrhage, increased blood pressure[Ref]


Uncommon (0.1% to 1%): Anxiety
Rare (0.01% to 0.1%): Confusion, depressive moods, dreams[Ref]


Rare (0.01% to 0.1%): Disorder of calcium metabolism, disorder of phosphate metabolism, fluid disturbances, hyperglycemia, hypofunction[Ref]


Rare (0.01% to 0.1%): Fungal infections, fungal reproductive infections, reproductive infections[Ref]


Rare (0.01% to 0.1%): Quantitative hemoglobin defects, quantitative red cell defects[Ref]


Rare (0.01% to 0.1%): Light sensitivity of eyes[Ref]


Rare (0.01% to 0.1%): Hypothalamus/pituitary hypofunction[Ref]


1. "Product Information. Lotronex (alosetron)." Glaxo Wellcome, Research Triangle Park, NC.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.