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Alpha Glucosidase Inhibitor

Alpha-glucosidase inhibitors delay glucose absorption and lower post-prandial glucose levels by inhibiting enzymes needed to digest carbohydrates. Glucobay® is the only medication from this class available in Canada.

1. Therapeutic Considerations

 All information from medication product monograph unless referenced below. 

A1c Lowering 0.5-1.0%1 
Hypoglycemia Risk  Low; *Treat with glucose (dextrose) tablets as sucrose absorption is inhibited by this medication. 
Class Side Effects Gastrointestinal (GI) side effects including flatulence, bloating and/or diarrhea. Diets high in sucrose (cane sugar) can contribute to greater GI intolerance. 
Vascular Protection No
Renal Protection No
Heart Failure Hospitalization Benefit No
Weight  Neutral 
Cost, Blue Cross coverage;  strengths;  dosing frequency; indications

Visit this class in the Complete Diabetes Medications Table  

Combination Medications None 
Advice for times of dehydration, vomiting, diarrhea Diabetes Canada advises this medication be taken as directed unless otherwise directed by a healthcare provider.

Tablet to be taken with first bite of food. 


2. Dosing Considerations

  •  The daily dose of acarbose may be adjusted based on 2 hour post prandial glucose levels and/or A1c level. 
  • Usual starting dose is 50 mg once daily. After 1-2 weeks dosage increased to 50 mg twice daily, then increased to 50 mg three times daily after further 1-2 weeks. 
  • Starting with a low dose and titrating up slowly may help reduce potential GI side effects. 
  • Not advised for eGFR < 30. Refer to Renal Impairment Considerations, Diabetes Canada. 


1. Inzucchi SE, Bergenstal RM, Buse JB, det al. Management of hyperglycemia in type 2 diabetes: a patient-centred approach. Diabetes Care 2012; 35: 1364-79. (Accessed Feb 26, 2018).