Zavesca Side Effects

Generic Name: miglustat

Note: This document contains side effect information about miglustat. Some of the dosage forms listed on this page may not apply to the brand name Zavesca.

Some side effects of Zavesca may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

For the Consumer

Applies to miglustat: oral capsule

Along with its needed effects, miglustat (the active ingredient contained in Zavesca) 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 miglustat:

More common
  • Black, tarry stools
  • bleeding gums
  • blood in urine or stools
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • pinpoint red spots on skin
  • unusual bleeding or bruising
  • Painful sensations
  • shakiness in legs, arms, hands, feet
  • trembling or shaking of hands or feet
  • unsteadiness or awkwardness
  • weakness in arms, hands, legs, or feet

Some side effects of miglustat 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:

More Common
  • Acid or sour stomach
  • back pain
  • belching
  • bloated, full feeling
  • change in vision
  • cramps
  • diarrhea
  • difficulty having a bowel movement (stool)
  • dizziness
  • dry mouth
  • excess air or gas in stomach or intestines
  • full or bloated feeling or pressure in the stomach
  • headache
  • heartburn
  • heaviness in limbs
  • indigestion
  • leg cramps
  • loss of appetite
  • memory loss
  • menstrual changes
  • nausea
  • pain or discomfort in chest, upper stomach, or throat
  • passing gas
  • stomach discomfort, upset or pain
  • swelling
  • swelling of abdominal or stomach area
  • unsteady walk
  • vomiting
  • weakness
  • weight loss

For Healthcare Professionals

Applies to miglustat: oral capsule


Osmotic diarrhea appears to be the result of the disaccharidase inhibitory activity of miglustat (the active ingredient contained in Zavesca)

Gastrointestinal side effects have included diarrhea (67% to 89%), flatulence (29% to 70%), abdominal pain (18% to 50%), nausea (14% to 35%), vomiting (30% to 33%), dysphagia (20% to 25%), and abdominal distension (20%). Epigastric pain not food-related, dyspepsia, dry mouth, constipation, anorexia, and bloating have also been reported.

Nervous system

Nervous system side effects have included headache (30% to 45%), tremors (30% to 40%), gait abnormal (33%), exacerbation of existing tremor (25% to 30%), gait spastic (25%), ataxia (25%), hyperreflexia (25%), and paresthesia (20%). Dizziness, cramps in legs, unsteady gait, and migraine have also been reported.


Metabolic side effects including weight decrease has been reported in 25% to 65% of patients.


Ocular side effects have included visual disturbances.


Hematologic side effects have included thrombocytopenia.


Genitourinary side effects have included menstrual disorder in the female patient.


General side effects have included abdominal distension (20%), abdominal distension with gas, generalized weakness, back pain, and heaviness in limbs.


Respiratory side effects have included nasopharyngitis (33% to 35%), cough 33%, and sinusitis (25%).


Psychiatric side effects have included insomnia (30%), decreased appetite (25%), and depression (20%).


Other side effects have included fatigue (35% to 42%) and lacerations (20%).

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