Miglustat Bluefish
Substrate reduction therapy for Gaucher disease and Niemann-Pick type C
Quick Facts About Miglustat Bluefish
Key Takeaways
- Dual indication: Miglustat Bluefish treats both Gaucher disease type 1 (when enzyme replacement therapy is not suitable) and neurological symptoms of Niemann-Pick disease type C
- Oral alternative: Unlike enzyme replacement therapy which requires intravenous infusions, miglustat is taken as an oral capsule at home
- Gastrointestinal effects are common: Diarrhea, flatulence, and abdominal pain affect most patients but often improve with dietary adjustments and over time
- Pregnancy contraindicated: Both women and men must use reliable contraception during treatment and for 3 months after stopping
- Regular monitoring required: Nerve function, vitamin B12 levels, and platelet counts should be checked before and during treatment
What Is Miglustat Bluefish and What Is It Used For?
Miglustat Bluefish is a prescription medicine containing the active substance miglustat, an iminosugar that inhibits the enzyme glucosylceramide synthase. It is used for substrate reduction therapy in two rare inherited metabolic diseases: Gaucher disease type 1 and Niemann-Pick disease type C.
Miglustat Bluefish belongs to a group of medicines that affect cellular metabolism by reducing the production of glycosphingolipids – complex fatty substances that accumulate to harmful levels in patients with certain lysosomal storage disorders. The active ingredient, miglustat, acts as a competitive inhibitor of glucosylceramide synthase, which catalyzes the first committed step in glycosphingolipid biosynthesis. By slowing the production of these substrates, the drug helps balance the impaired ability of the body to break them down.
Gaucher Disease Type 1
Gaucher disease type 1 is the most common form of Gaucher disease, a rare autosomal recessive disorder caused by deficiency of the lysosomal enzyme glucocerebrosidase (also known as acid beta-glucosidase). In patients with this condition, a substance called glucosylceramide cannot be properly removed from the body and begins to accumulate in macrophages of the reticuloendothelial system. This progressive accumulation leads to hepatosplenomegaly (enlargement of the liver and spleen), hematological abnormalities including anemia and thrombocytopenia, and skeletal complications such as bone pain, osteoporosis, and avascular necrosis.
The standard first-line treatment for Gaucher disease type 1 is enzyme replacement therapy (ERT) with agents such as imiglucerase or velaglucerase alfa, administered intravenously every two weeks. Miglustat Bluefish is indicated specifically for the treatment of mild to moderate Gaucher disease type 1 in adult patients for whom enzyme replacement therapy is considered unsuitable. This may include patients with severe needle phobia, poor venous access, or hypersensitivity reactions to ERT, as well as those who prefer oral therapy and whose disease severity allows for this alternative approach.
Niemann-Pick Disease Type C
Niemann-Pick disease type C (NPC) is an extremely rare, progressive, and ultimately fatal neurodegenerative disorder caused by mutations in the NPC1 or NPC2 genes. These mutations impair intracellular lipid trafficking, leading to accumulation of unesterified cholesterol and glycosphingolipids in lysosomes and late endosomes. The neurological manifestations of NPC are particularly devastating and include vertical supranuclear gaze palsy, cerebellar ataxia, dysarthria, dysphagia, progressive cognitive decline, seizures, and psychiatric symptoms.
Miglustat Bluefish is indicated for the treatment of progressive neurological manifestations of Niemann-Pick disease type C in both adults and children. In clinical studies, miglustat has been shown to stabilize key neurological markers, including horizontal saccadic eye movement velocity and swallowing capacity. While miglustat does not cure NPC, it can slow the progression of neurological deterioration and may help preserve functional abilities for longer periods.
Miglustat works through substrate reduction therapy (SRT). Rather than replacing a missing enzyme (as in enzyme replacement therapy), miglustat reduces the production of the substrates that accumulate. It inhibits glucosylceramide synthase, the enzyme responsible for the first step in synthesizing most glycosphingolipids. This approach reduces the amount of substrate that needs to be processed, helping to rebalance the system even when enzyme activity is impaired.
What Should You Know Before Taking Miglustat Bluefish?
Before starting Miglustat Bluefish, inform your doctor about any kidney or liver disease. Do not take this medicine if you are allergic to miglustat. Both men and women must use effective contraception. Regular monitoring of nerve function, vitamin B12, and blood counts is required.
Contraindications
Miglustat Bluefish must not be taken if you are allergic (hypersensitive) to miglustat or any of the other ingredients in the capsule, which include sodium starch glycolate type A, povidone, magnesium stearate, titanium dioxide (E171), and gelatin. Allergic reactions to these excipients are rare, but patients should be aware of the complete formulation before initiating treatment.
Warnings and Precautions
Before starting treatment with Miglustat Bluefish, it is essential to discuss your complete medical history with your prescribing physician. Particular attention should be given to the following conditions and monitoring requirements:
- Kidney disease: Patients with impaired renal function may require dose adjustments because miglustat is primarily excreted by the kidneys. Reduced creatinine clearance can lead to increased drug exposure and higher risk of adverse effects
- Liver disease: Although miglustat does not undergo significant hepatic metabolism, patients with liver disease should be monitored closely as the underlying conditions being treated can themselves affect liver function
- Peripheral neuropathy: Your doctor will perform nerve conduction studies before starting treatment and at regular intervals (typically every 6 months) during therapy. Some patients develop tingling, numbness, or burning sensations in the hands and feet. If symptoms of peripheral neuropathy worsen significantly, your doctor may need to discontinue treatment
- Vitamin B12 monitoring: Vitamin B12 levels should be measured before starting treatment and monitored periodically, as deficiency has been observed in patients taking miglustat
- Platelet counts: Thrombocytopenia (low platelet counts) has been reported during treatment, though this must be distinguished from thrombocytopenia caused by the underlying Gaucher disease
- Growth monitoring: Children and adolescents with Niemann-Pick disease type C should have their growth (height and weight) monitored regularly during treatment
Pregnancy and Breastfeeding
Miglustat Bluefish must not be used during pregnancy. Animal studies have shown reproductive toxicity including effects on spermatogenesis. Women of childbearing potential must use effective contraception during treatment. Male patients must use reliable contraception during treatment and for 3 months after stopping Miglustat Bluefish. Breastfeeding is contraindicated during treatment. If you are pregnant, think you may be pregnant, or are planning to have a baby, consult your doctor before taking this medicine.
Driving and Operating Machinery
Miglustat Bluefish can cause dizziness and tremor, which may impair your ability to drive or operate machinery safely. Patients should assess their own fitness to perform tasks requiring alertness and coordination. If you experience dizziness or other neurological symptoms, avoid driving vehicles or using heavy machinery until symptoms resolve. You are personally responsible for assessing whether you are fit to drive or perform tasks requiring heightened attention.
Sodium Content
This medicine contains less than 1 mmol (23 mg) sodium per hard capsule, meaning it is essentially sodium-free. This is relevant for patients on a controlled sodium diet.
How Does Miglustat Bluefish Interact with Other Drugs?
Miglustat Bluefish has relatively few known drug interactions. The most significant interaction is with imiglucerase (enzyme replacement therapy for Gaucher disease), which may reduce miglustat blood levels when used concomitantly. Always inform your doctor of all medications you are taking.
The drug interaction profile of miglustat is relatively favorable compared to many other medications, partly because it does not undergo significant cytochrome P450 metabolism. However, several interactions have been identified or are theoretically possible based on the pharmacokinetic properties of the drug.
| Drug | Type | Effect | Recommendation |
|---|---|---|---|
| Imiglucerase | Pharmacokinetic | May reduce miglustat blood levels (reduced AUC and Cmax) | Inform your doctor; dose adjustment may be needed |
| Loperamide | Co-administration | Often prescribed to manage miglustat-induced diarrhea | Safe to use together; follow doctor's dosing guidance |
| Other glycosphingolipid-reducing agents | Pharmacodynamic | Potential additive effect on glycosphingolipid reduction | Avoid combination unless specifically directed by specialist |
It is important to inform your doctor or pharmacist about all medicines you are currently taking, have recently taken, or might take. This includes prescription medications, over-the-counter drugs, herbal supplements, and vitamins. While miglustat has a limited interaction profile, individual patient factors such as renal function and concurrent conditions may influence how the drug behaves in your body.
Food Interactions
Miglustat Bluefish can be taken with or without food. However, if you experience significant gastrointestinal side effects, particularly diarrhea, your doctor may recommend taking the capsules separately from meals. Additionally, reducing your dietary intake of carbohydrates, lactose (milk sugar), and sucrose (table sugar) can help manage diarrhea. This is because miglustat also inhibits intestinal disaccharidases, enzymes that break down complex sugars in the gut.
What Is the Correct Dosage of Miglustat Bluefish?
The dosage of Miglustat Bluefish depends on the condition being treated. For Gaucher disease type 1 in adults: 100 mg three times daily. For Niemann-Pick type C in adults and adolescents over 12: 200 mg three times daily. Children's doses are adjusted based on body surface area.
Always take Miglustat Bluefish exactly as your doctor has prescribed. The capsules should be swallowed whole with a glass of water. Do not open, crush, or chew the capsules. Your doctor will determine the appropriate dose based on your condition, age, weight, and kidney function.
Adults – Gaucher Disease Type 1
Standard Adult Dose – Gaucher Disease Type 1
100 mg (one capsule) three times daily – morning, afternoon, and evening. This gives a maximum daily dose of 300 mg. Treatment is typically long-term and continued as long as clinical benefit is maintained.
Adults and Adolescents – Niemann-Pick Type C
Standard Dose – Niemann-Pick Type C (Over 12 Years)
200 mg (two capsules) three times daily – morning, afternoon, and evening. This gives a maximum daily dose of 600 mg. Treatment should be continued as long as the patient derives clinical benefit.
Children – Niemann-Pick Type C
For children under 12 years of age with Niemann-Pick disease type C, the dose is adjusted by the treating physician based on the child's body surface area. Miglustat Bluefish is not approved for use in children and adolescents under 18 years old with Gaucher disease type 1, as efficacy and safety have not been established in this population for that indication.
| Indication | Patient Group | Dose | Frequency | Max Daily |
|---|---|---|---|---|
| Gaucher disease type 1 | Adults (≥18 years) | 100 mg | Three times daily | 300 mg |
| Niemann-Pick type C | Adults and adolescents (>12 years) | 200 mg | Three times daily | 600 mg |
| Niemann-Pick type C | Children (<12 years) | Adjusted by physician | Based on body surface area | Individualized |
Dose Adjustments for Renal Impairment
Patients with impaired kidney function may require a reduced starting dose. Miglustat is primarily excreted by the kidneys, and reduced creatinine clearance leads to increased drug exposure. Your doctor will assess your renal function before starting treatment and adjust the dose accordingly. In some cases, particularly moderate to severe renal impairment, the dose may be reduced to 100 mg once or twice daily.
Dose Adjustments for Diarrhea
If you experience persistent diarrhea during treatment, your doctor may temporarily reduce the dose – for example, to 100 mg once or twice daily. Dietary modifications should also be implemented, including reducing intake of lactose, sucrose, and complex carbohydrates. Anti-diarrheal medications such as loperamide may be prescribed as needed.
Missed Dose
If you forget to take a dose, take the next capsule at your usual scheduled time. Do not take a double dose to make up for a missed dose. Maintaining a regular dosing schedule helps keep stable blood levels of the medication.
Overdose
If you have taken too much Miglustat Bluefish or a child has accidentally ingested the medicine, contact a doctor, hospital emergency department, or poison control center immediately. In clinical trials, miglustat has been used at doses up to 3000 mg. At these supratherapeutic doses, decreased white blood cell counts (leukopenia) and other adverse effects similar to those described in the side effects section have been observed.
Stopping Treatment
Do not stop taking Miglustat Bluefish without consulting your doctor. Abrupt discontinuation may lead to worsening of your underlying condition, particularly in Niemann-Pick disease type C where neurological symptoms may progress. If treatment needs to be discontinued, your doctor will advise on the appropriate approach.
What Are the Side Effects of Miglustat Bluefish?
The most common side effects of Miglustat Bluefish are gastrointestinal: diarrhea, flatulence, abdominal pain, weight loss, and decreased appetite. These affect more than 1 in 10 patients but often improve over time. Peripheral neuropathy (tingling/numbness) and tremor are important effects to report to your doctor promptly.
Like all medicines, Miglustat Bluefish can cause side effects, although not everybody gets them. The most frequently reported adverse effects are gastrointestinal in nature and typically occur during the initial weeks of treatment. Most patients experience at least one side effect, particularly early in therapy. In the majority of cases, side effects are mild to moderate and resolve over time or with dose adjustments and dietary modifications.
Very Common Side Effects
- Diarrhea
- Flatulence (excessive gas)
- Abdominal (stomach) pain
- Weight loss
- Decreased appetite
Common Side Effects
- Headache
- Dizziness
- Paraesthesia (tingling or numbness in hands and feet)
- Abnormal coordination
- Hypoesthesia (reduced sensation)
- Tremor (usually mild, mainly in hands)
- Nausea
- Vomiting
- Constipation
- Dyspepsia (heartburn, indigestion)
- Abdominal distension or discomfort
- Thrombocytopenia (decreased platelet levels)
Other Reported Side Effects
- Muscle spasms or weakness
- Fatigue
- Chills and general malaise
- Depression
- Insomnia (difficulty sleeping)
- Memory impairment
- Decreased libido
The gastrointestinal side effects of miglustat are largely related to its inhibition of intestinal disaccharidases. Dietary modifications can significantly reduce these effects: reduce intake of lactose (dairy products), sucrose (table sugar), and complex carbohydrates. Your doctor may also recommend taking miglustat separately from meals or may prescribe loperamide for persistent diarrhea. Weight loss typically stabilizes as treatment continues.
Peripheral Neuropathy
Some patients develop peripheral neuropathy during treatment with miglustat, manifesting as tingling, numbness, or burning sensations in the hands and feet. This is one of the more clinically significant adverse effects and requires careful monitoring. Nerve conduction studies should be performed at baseline and at regular intervals (typically every 6 months) during treatment. It is important to distinguish between neuropathy caused by the medication and neuropathy that may be part of the underlying disease, particularly in Gaucher disease patients who can develop neuropathy independently of treatment.
Tremor
Tremor, usually mild and predominantly affecting the hands, has been reported in patients taking miglustat. In most cases, the tremor resolves without treatment discontinuation. If tremor is bothersome, your doctor may consider a dose reduction or, in more severe cases, may need to stop treatment. Report any new or worsening tremor to your doctor promptly.
Seek medical advice promptly if you experience new or worsening tingling or numbness in your hands and feet, significant tremor, persistent diarrhea not responding to dietary changes, or any other symptoms that concern you. Do not stop taking the medication without first consulting your doctor.
How Should You Store Miglustat Bluefish?
Store Miglustat Bluefish out of the sight and reach of children. Do not use after the expiry date (EXP) printed on the carton. No special storage conditions are required beyond keeping the medication in a safe place.
Proper storage of Miglustat Bluefish is important to ensure the medication remains effective and safe throughout its shelf life. The capsules are supplied in perforated Aclar-aluminium blisters (PVC/PE/PCTFE-aluminium blister packs) that provide adequate protection from moisture and light under normal storage conditions.
- Keep out of the sight and reach of children – Store the medication in a secure location where children cannot access it
- Check the expiry date – Do not use Miglustat Bluefish after the expiry date stated on the packaging. The expiry date refers to the last day of that month
- No special storage temperature required – Store at room temperature unless otherwise directed by your pharmacist
- Proper disposal – Do not dispose of medications via wastewater or household waste. Ask your pharmacist how to properly dispose of medicines you no longer use. These measures help protect the environment
What Does Miglustat Bluefish Contain?
Each Miglustat Bluefish capsule contains 100 mg of miglustat as the active substance. The capsules are white hard gelatin capsules filled with homogeneous white to off-white granules, available in packs of 84 capsules.
Understanding the full composition of your medication is important, particularly if you have known allergies or sensitivities to any pharmaceutical excipients. Below is the complete list of ingredients in Miglustat Bluefish 100 mg hard capsules:
Active Substance
Each hard capsule contains 100 mg miglustat. Miglustat (also known as N-butyldeoxynojirimycin or NB-DNJ) is an iminosugar – a small molecule that structurally resembles glucose. This structural similarity allows it to competitively inhibit glucosylceramide synthase. The 65 mg strength capsules are also available for dose adjustment purposes.
Other Ingredients (Excipients)
| Component | Ingredient | Function |
|---|---|---|
| Capsule contents | Sodium starch glycolate type A | Disintegrant |
| Capsule contents | Povidone | Binder |
| Capsule contents | Magnesium stearate | Lubricant |
| Capsule shell | Titanium dioxide (E171) | Colourant (white) |
| Capsule shell | Gelatin | Capsule shell material |
Appearance and Pack Size
Miglustat Bluefish 100 mg hard capsules are white, hard gelatin capsules filled with homogeneous white to off-white granules. They are supplied in perforated Aclar-aluminium blisters. The standard pack size is 84 hard capsules, which corresponds to approximately 28 days of treatment at the standard dose for Gaucher disease type 1 (100 mg three times daily).
Marketing Authorization Holder
Bluefish Pharmaceuticals AB, P.O. Box 49013, 100 28 Stockholm, Sweden. The capsules are manufactured by G.L. Pharma GmbH, Industriestrasse 1, A-8502 Lannach, Austria. This medicine is authorized in the European Economic Area under the name Miglustat Bluefish in multiple countries including Germany, Denmark, France, Norway, and Sweden.
Frequently Asked Questions About Miglustat Bluefish
Miglustat Bluefish is used to treat two rare inherited metabolic conditions: mild to moderate Gaucher disease type 1 in adults (when enzyme replacement therapy is not suitable), and progressive neurological symptoms of Niemann-Pick disease type C in both adults and children. It works by reducing the production of harmful fatty substances (glycosphingolipids) that accumulate in the body due to these diseases.
The most common side effects are gastrointestinal: diarrhea, flatulence, abdominal pain, weight loss, and decreased appetite. These affect more than 1 in 10 patients but usually improve over time with dietary adjustments. Reducing intake of dairy products (lactose), sugar, and carbohydrates can help significantly. Other common effects include headache, dizziness, tingling in hands and feet, and tremor.
No. Miglustat Bluefish must not be taken during pregnancy or while breastfeeding. Women of childbearing potential must use effective contraception throughout treatment. Male patients must also use reliable contraception during treatment and for 3 months after the last dose, as the drug may affect sperm. If you suspect you may be pregnant, stop the medication and contact your doctor immediately.
Enzyme replacement therapy (ERT) works by providing the missing or deficient enzyme through intravenous infusions, typically every two weeks. Miglustat Bluefish takes a different approach called substrate reduction therapy: instead of replacing the enzyme, it reduces the production of the substance that accumulates. The key practical advantage is that miglustat is an oral capsule taken at home, whereas ERT requires hospital or clinic visits for infusions. However, miglustat is only used for Gaucher disease type 1 when ERT is considered unsuitable.
Diarrhea is the most common side effect and usually improves over time. Several strategies can help: reduce your intake of lactose (dairy products), sucrose (sugar), and complex carbohydrates. Your doctor may suggest taking the capsules separately from meals. Anti-diarrheal medicine such as loperamide can be used if needed. If diarrhea persists despite these measures, your doctor may temporarily reduce your dose. Do not stop taking the medication without medical advice.
Regular monitoring is essential during miglustat treatment. This includes nerve conduction studies (typically every 6 months) to check for peripheral neuropathy, vitamin B12 level measurements, and platelet count monitoring. For children and adolescents with Niemann-Pick type C, growth should also be tracked. These baseline tests are performed before starting treatment and repeated at regular intervals throughout therapy.
References and Sources
- European Medicines Agency (EMA). Miglustat – Summary of Product Characteristics (SmPC). European Medicines Agency, 2024. Available at: www.ema.europa.eu
- Cox TM, Lachmann RH, Hollak C, et al. Novel oral treatment of Gaucher's disease with N-butyldeoxynojirimycin (OGT 918) to decrease substrate biosynthesis. The Lancet. 2000;355(9214):1481-1485. doi:10.1016/S0140-6736(00)02161-9
- Patterson MC, Vecchio D, Prady H, Abel L, Wraith JE. Miglustat for treatment of Niemann-Pick C disease: a randomised controlled study. The Lancet Neurology. 2007;6(9):765-772. doi:10.1016/S1474-4422(07)70194-1
- Hollak CE, Hughes D, van Schaik IN, Schwierin B,"; vGemert GW. Miglustat (Zavesca) in type 1 Gaucher disease: 5-year results of a post-authorisation safety surveillance programme. Pharmacoepidemiology and Drug Safety. 2009;18(9):770-777.
- World Health Organization (WHO). WHO Model List of Essential Medicines – 23rd List, 2023. Geneva: World Health Organization, 2023.
- Pastores GM, Giraldo P, Cherin P, Mehta A. Goal-oriented therapy with miglustat in Gaucher disease. Current Medical Research and Opinion. 2009;25(1):23-37.
- Patterson MC, Hendriksz CJ, Walterfang M, Sedel F, Vanier MT, Wijburg F. Recommendations for the diagnosis and management of Niemann-Pick disease type C: An update. Molecular Genetics and Metabolism. 2012;106(3):330-344.
- British National Formulary (BNF). Miglustat. National Institute for Health and Care Excellence (NICE), 2024. Available at: bnf.nice.org.uk
About Our Medical Editorial Team
Medical Authors
Board-certified specialists in pharmacology and internal medicine with expertise in rare metabolic diseases and lysosomal storage disorders
Medical Reviewers
Independent panel of physicians who verify all medical claims against current EMA, FDA, and WHO guidelines
Evidence Standard
All content follows the GRADE evidence framework. Information is based on systematic reviews, clinical trials, and authoritative regulatory sources
Editorial Independence
No pharmaceutical sponsorship or commercial funding. All content is independently produced and reviewed without conflicts of interest
Learn more about our medical team | Read our editorial standards