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Miglustat Side Effects

Not all side effects for miglustat may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to miglustat: oral capsule

In addition to its needed effects, some unwanted effects may be caused by miglustat. In the event that any of these side effects do occur, they may require medical attention.

You should check with your doctor immediately if any of these side effects occur when taking miglustat:

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

Some of the side effects that can occur with miglustat may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common
  • Back pain
  • bloated or full feeling
  • blurred or loss of vision
  • difficulty having a bowel movement (stool)
  • disturbed color perception
  • dizziness
  • double vision
  • dry mouth
  • excess air or gas in the stomach or intestines
  • halos around lights
  • headache
  • heartburn
  • heaviness in the limbs
  • indigestion
  • leg cramps
  • loss of appetite
  • memory loss
  • menstrual changes
  • nausea
  • pain or discomfort in the chest, upper stomach, or throat
  • passing gas
  • stomach discomfort, upset or pain
  • swelling of the abdominal or stomach area
  • tunnel vision
  • unsteady walk
  • vomiting

For Healthcare Professionals

Applies to miglustat: oral capsule


The most common serious side effect was peripheral neuropathy. Diarrhea and tremor were the side effects that required intervention most often.[Ref]


Osmotic diarrhea appears to be due to inhibitory activity of miglustat on intestinal disaccharidases leading to reduced absorption of dietary disaccharides in the small intestine. Diarrhea decreased over time with continued therapy.[Ref]

Very common (10% or more): Diarrhea (including osmotic diarrhea; up to 100%), abdominal pain (up to 67%), flatulence (up to 50%), nausea (up to 22%), vomiting (up to 11%)
Common (1% to 10%): Constipation, dry mouth, dyspepsia, epigastric pain not food-related, bloating
Frequency not reported: Dysphagia[Ref]


Very common (10% or more): Weight decrease (up to 67%)
Common (1% to 10%): Anorexia[Ref]

Nervous system

Very common (10% or more): Tremor/exacerbation of existing tremor (about 30%), headache (up to 22%), tremor (up to 17%), dizziness (up to 11%), leg cramps (up to 11%)
Common (1% to 10%): Unsteady gait, paresthesia, migraine, peripheral neuropathy
Frequency not reported: Gait abnormal, gait spastic, ataxia, hyperreflexia[Ref]


Very common (10% or more): Generalized weakness (up to 17%)
Common (1% to 10%): Abdominal distension, back pain, heaviness in limbs, pain
Frequency not reported: Abdominal distension with gas, fatigue, lacerations[Ref]


Very common (10% or more): Visual disturbances (up to 17%)[Ref]


Very common (10% or more): Cramps (up to 11%)[Ref]


Common (1% to 10%): Memory loss
Frequency not reported: Insomnia, decreased appetite, depression[Ref]


Common (1% to 10%): Thrombocytopenia
Frequency not reported: Mild reduction in platelet count[Ref]


Common (1% to 10%): Menstrual disorder[Ref]


Frequency not reported: Nasopharyngitis, cough, sinusitis


1. "Product Information. Zavesca (miglustat)." Acetelion Pharmaceuticals US, Inc, South San Francisco, CA.

2. Patterson MC, Vecchio D, Prady H, Abel L, Wraith JE "Miglustat for treatment of Niemann-Pick C disease: a randomised controlled study." Lancet Neurol 6 (2007): 765-72

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