I googled Miglustat and the side effects are pretty lengthy. Might be one of those meds that you only take if absolutely necessary.

What are the possible side effects of miglustat?
Nerve problems such as numbness, tingling, and tremor (shaking) of the hands have been reported by some people taking miglustat. Contact your doctor immediately if you experience new or worsening numbness, tingling, or burning in the hands, arms, legs, or feet or tremor in the hands.
Seek emergency medical attention if you experience a rare but serious allergic reaction to miglustat including difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives.
Other less serious side effects may be more likely to occur. Continue to take miglustat and talk to your doctor if you experience:

diarrhea;
decreased appetite or weight loss;
gas or abdominal pain;
constipation;
muscle cramps or weakness;
headache;
dizziness; or
vision problems.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.