Miglitol
Other glucose-lowering drugs
Other glucose-lowering drugs
An alpha-glucosidase inhibitor taken with meals: it slows starch and sugar digestion in the gut and blunts the rise of glucose after eating.
Quick facts
- Group
- Other glucose-lowering drugs
- Target
- Intestinal alpha-glucosidases (maltase-glucoamylase, sucrase)
- Used for
- Type 2 diabetes
- Key effects
- Flatulence · Diarrhoea · Abdominal pain
- Monitor
- Post-meal and fasting glucose · Kidney function
- ATC
- A10BF02
No doses: the clinician sets them by the current guideline.
Mechanism of action
The figure shows miglitol in the active site of the N-terminal domain of human intestinal maltase-glucoamylase.
Miglitol is a glucose-like (deoxynojirimycin) molecule that competitively inhibits the alpha-glucosidases of the small-intestinal brush border. Starch and disaccharides such as sucrose are broken down and absorbed more slowly, so the post-meal glucose peak is lower. Undigested carbohydrate reaches the colon, where bacteria ferment it, causing gas and diarrhoea.
- Competitively blocks brush-border alpha-glucosidases
- Starch and sucrose are split into glucose more slowly
- Glucose enters the blood gradually after meals
- Post-meal glucose peak falls; fermentation causes gas
Indications
- Type 2 diabetes, with diet and exercise, to lower post-meal glucose Type 2 diabetes mellitus →
Adverse effects
Common
- Flatulence
- Diarrhoea
- Abdominal pain
- Skin rash
Contraindications
- Diabetic ketoacidosis
- Inflammatory bowel disease, colonic ulceration or partial intestinal obstruction, or predisposition to obstruction
- Chronic intestinal disease with marked malabsorption, or conditions worsened by more intestinal gas
- Hypersensitivity to the drug
Key interactions
- Intestinal adsorbents (charcoal) and carbohydrate-splitting digestive enzyme preparations (amylase, pancreatin)
- Reduce miglitol's effect; not taken together.
- Propranolol and ranitidine
- Their bioavailability can fall.
- Digoxin
- Plasma digoxin was lower in healthy volunteers (but not in a study of diabetic patients).
- Insulin or sulfonylureas
- Higher risk of hypoglycaemia.
What is monitored
- Post-meal and fasting glucose, HbA1c
- Kidney function
- Gastrointestinal tolerance
Administration and safety
- Oral tablet, taken with the first bite of each main meal.
- Started low and increased gradually to limit gas and diarrhoea.
- Hypoglycaemia (with other drugs) is treated with glucose (dextrose), not sucrose.
Pregnancy and breastfeeding
Safety in pregnancy is not established; insulin is the usual treatment for diabetes in pregnancy.
Nursing care
- Before: bowel disease, kidney function.
- During: gas, bloating, diarrhoea; glucose before and after meals.
- Teach to keep glucose tablets or gel, not sugar or candy, for hypoglycaemia.
- Teach that the tablet is skipped if the meal is skipped.
Pharmacokinetics
- Absorption
- Unlike acarbose it is absorbed, saturably (less at higher amounts).
- Metabolism
- Not metabolized.
- Elimination
- Excreted unchanged by the kidneys; it accumulates in kidney impairment.
Test yourself
Think of the answer, then tap the question to see it.
How should hypoglycaemia be treated in a patient on miglitol plus a sulfonylurea?
With oral glucose (dextrose), because miglitol blocks the splitting of sucrose.
How does miglitol differ from acarbose pharmacokinetically?
Miglitol is absorbed and excreted unchanged by the kidneys; acarbose is barely absorbed.
Why does miglitol cause flatulence?
Undigested carbohydrate reaches the colon, where bacteria ferment it.
Connections
← Back to the class: Other glucose-lowering drugs
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Miglitol: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); DailyMed - MIGLITOL tablet, coated (DailyMed (U.S. National Library of Medicine), 2022); Crystal complex of N-terminal Human Maltase-Glucoamylase with miglitol (RCSB Protein Data Bank, 2010).
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Representative model, for educational purposes only.