(British Approved Name, US Adopted Name, rINN)

International Nonproprietary Names (INNs) in main languages (French, Latin, and Spanish): Acarbosa; Acarbosum; Akarboosi; Akarbos; Akarbosa; Akarboz; Akarboze; Bay-g-5421.

Pharmacopoeias. In Europe and US.

European Pharmacopoeia, 6th ed. (Acarbose). A white or yellowish, amorphous, hygroscopic powder. Very soluble in water practically insoluble in dichloromethane soluble in methyl alcohol. A 5% solution in water has a pH of 5.5 to 7.5. Store in airtight containers.

The United States Pharmacopeia 31, 2008 (Acarbose). Produced by certain strains of Actinoplanes utahensis. Store in airtight containers.

Adverse Effects

Acarbose often causes gastrointestinal disturbances, particularly flatulence due to bacterial action on non-absorbed carbohydrate in the colon. Abdominal distension, diarrhoea, and pain may occur. Ileus has been rarely reported. A decrease in dosage and improved dietary habits may reduce these adverse effects. Hepatotoxicity may occur and may necessitate a reduction in dosage or withdrawal of the drug. Skin reactions have occurred rarely. Very rarely oedema has been reported.

Incidence of adverse effects. The manufacturers reported that adverse effects of acarbose were rarer in a postmarketing surveillance study than in previous clinical trials this was held to represent better tailoring of individual doses to patient tolerability.

Effects on the liver. Hepatocellular liver damage, with jaundice and elevated serum aminotransferases, have been reported in patients receiving acarbose. Symptoms resolved on stopping the drug.

Effects on the skin. Generalised erythema multiforme and eosinophilia occurred in a male diabetic patient 13 days after starting acarbose. The hypersensitivity reaction was confirmed by rechallenge.

Precautions

Acarbose is contra-indicated in inflammatory bowel disease, particularly where there is associated ulceration, and in gastrointestinal obstruction or patients predisposed to it. It should be avoided in patients with chronic intestinal diseases that significantly affect digestion or absorption, and in conditions which may deteriorate as a result of increased gas formation, such as hernia.

Acarbose is also contra-indicated in patients with hepatic impairment and liver enzyme values should be monitored, particularly at high doses. If hypoglycaemia should develop in a patient receiving acarbose it needs to be treated with glucose, since the action of acarbose inhibits the hydrolysis of disaccharides.

Breast feeding. In the absence of evidence, licensed product information recommends that acarbose should be avoided during breastfeeding.

Interactions

Acarbose may enhance the effects of other antidiabetics, including insulin, and a reduction in their dosage may be needed. Use with gastrointestinal adsorbents and digestive enzyme preparations can diminish the effects of acarbose and should be avoided. Neomycin and colestyramine may enhance the effects of acarbose and a reduction in its dosage may be required. Acarbose may inhibit the absorption of digoxin.

Pharmacokinetics

After ingestion of acarbose, the majority of active unchanged drug remains in the lumen of the gastrointestinal tract to exert its pharmacological activity and is metabolised by intestinal enzymes and by the microbial flora. Ultimately about 35% of a dose is absorbed in the form of metabolites. Acarbose is excreted in the urine and faeces.

Uses and Administration

Acarbose is an inhibitor of alpha glucosidases, especially sucrase. This slows the digestion and absorption of carbohydrates in the small intestine and hence reduces the increase in blood-glucose concentrations after a carbohydrate load. It is given in the treatment of type 2 diabetes mellitus either alone or with a sulfonylurea, biguanide, or insulin. Acarbose treatment may be started with a low oral dose of 25 or 50 mg daily to minimise gastrointestinal disturbance. It is then gradually increased to a usual dose of 25 or 50 mg three times daily, immediately before food. Doses up to 100 to 200 mg three times daily may be given if necessary. Some benefit has also been found when acarbose is used to supplement insulin therapy in type 1 diabetes mellitus.

Acarbose has also been studied for the treatment of reactive hypoglycaemia, the dumping syndrome, and certain types of hyperlipoproteinaemia.

Impaired glucose tolerance. A prospective study of patients with impaired glucose tolerance concluded that acarbose significantly reduced the incidence of cardiovascular disease and hypertension.

Preparations

Proprietary Preparations

Argentina: Glucobay

Australia: Glucobay

Austria: Glucobay

Belgium: Glucobay

Brazil: Aglucose Glucobay

Canada: Prandase

Chile: Glucobay

Czech Republic: Glucobay

Denmark: Glucobay

France: Glucor

Germany: Glucobay

Greece: Glucobay

Hong Kong: Glucobay

Hungary: Glucobay

India: Acarbay Asucrose Glubose Glucar Glucobay

Indonesia: Glucobay

Ireland: Glucobay

Israel: Prandase

Italy: Glicobase Glucobay

Malaysia: Dibose Glucar Glucobay Precose

Mexico: Glucobay Incardel Sincrosa

The Netherlands: Glucobay

Norway: Glucobay

New Zealand: Glucobay

Philippines: Glucobay Gluconase

Poland: Glucobay

Portugal: Glucobay

Russia: Glucobay (Глюкобай)

South Africa: Glucobay

Singapore: Glucobay

Spain: Glucobay Glumida

Sweden: Glucobay

Switzerland: Glucobay

Thailand: Glucobay

Turkey: Glucobay Glynose

UK: Glucobay

USA: Precose

Venezuela: Glucobay

Acarbose

Brand Name Drug: in Europe under the brand name Glucobay, in North America as Precose, and in Canada as Prandase

Acarbose and the other agents of this class have relatively weak antidiabetic activity, only reducing HgbA₁C by .5%-1% in most patients. Diarrhea and flatulence are the most common side effects, occurring in up to 40% of patients in most trials. Secondary to the high incidence of gastrointestinal distress, acarbose should be initiated slowly. It comes in 50-mg and 100-mg tablets, and it is currendy recommended that patients begin with 25 mg daily taken with a meal. Afterward, it can be advanced to 25 mg with two meals and slowly increased to a maximum of 300 mg/day. Acarbose should be taken with the first bite of the meal and the most benefit is achieved with doses > 150 mg/day. It is at these higher dosages that a recent study has shown reduction of HgbA₁C of 1%-2%. Unfortunately, the incidence of gastrointestinal side effects often precludes reaching these doses.

Miglitol

Brand Name Drug: Glyset

Recendy, miglitol, a new alpha-glucosidase inhibitor, was approved by the Food and Drug Administration. It reportedly has many of the gastrointestinal side effects that limit acarbose use. However, in preliminary studies, miglitol effectively lowered postprandial blood glucose and glycosylated hemoglobin levels.