Acarbose was developed as part of Bayer AG’s screening program in the 1970s aimed at finding amylase inhibitors. It was first isolated from bacterial sources during that time and later approved in the 1990s as an oral treatment for type 2 diabetes. As the first drug of its kind, acarbose was approved in the United States in 1995 under the brand name Precose, designed to slow carbohydrate absorption and help control post-meal blood sugar spikes. Unlike other diabetes medications that increase insulin secretion or sensitivity, acarbose works locally in the gastrointestinal tract by inhibiting enzymes such as alpha-glucosidase and pancreatic alpha-amylase. These enzymes are responsible for breaking down complex carbohydrates into glucose. By delaying carbohydrate digestion, acarbose slows glucose absorption, thereby reducing blood sugar spikes after meals. Acarbose was first approved in Germany in the early 1990s and later received FDA approval in the United States in 1995 under the brand name Precose. It became the first alpha-glucosidase inhibitor approved for clinical use. Although less commonly used today due to gastrointestinal side effects like gas and bloating, acarbose is still considered a valuable treatment option, especially in regions where dietary carbohydrate control is a central strategy in diabetes management.
Brand Names:
Precose was the brand name for acarbose in the United States. Although the original branded product has been discontinued, generic versions are still available on the market.
Prandase is the brand name under which acarbose is marketed in Canada.
Mechanism of Action:
Alpha-glucosidase enzymes are located in the brush border of the intestinal lining and play a key role in breaking down oligo-, tri-, and disaccharides (such as sucrose) into monosaccharides like glucose and fructose, which are more easily absorbed. These enzymes work alongside pancreatic alpha-amylase, found in the intestinal lumen, which breaks down complex starches into smaller oligosaccharides. Acarbose is a complex oligosaccharide that acts as a competitive and reversible inhibitor of both pancreatic alpha-amylase and membrane-bound alpha-glucosidases. Among the alpha-glucosidases, its inhibitory strength follows the order: glucoamylase > sucrase > maltase > isomaltase. By blocking the breakdown and absorption of dietary carbohydrates, acarbose helps to lower post-meal (postprandial) blood glucose and insulin levels.
PHARMACOKINETICS
Absorption:
Acarbose is minimally absorbed, with less than 2% of the active drug entering the bloodstream, making its effects primarily local rather than systemic. It works within the gastrointestinal tract to slow down the absorption of carbohydrates.
Distribution:
Due to its minimal systemic absorption (less than 2%), acarbose has very limited distribution throughout the body. The small amount that is absorbed is not widely distributed into tissues. Instead, acarbose primarily remains within the gastrointestinal tract, where it exerts its therapeutic effect by inhibiting carbohydrate-digesting enzymes. Because of its local action and limited absorption, it has a negligible volume of distribution.
Metabolism:
Acarbose undergoes extensive metabolism in the gastrointestinal (GI) tract, where it is broken down by intestinal bacteria and digestive enzymes into various metabolites, including 4-methylpyrogallol derivatives.
Elimination
The kidneys filter the absorbed drug, and 51% of an oral dose gets eliminated in feces.
PHARMACODYNAMICS
Acarbose exerts its pharmacodynamic effect by inhibiting alpha-glucosidase enzymes in the small intestine, slowing the breakdown of complex carbohydrates into absorbable monosaccharides such as glucose. This delay in carbohydrate digestion reduces the rate of glucose absorption, resulting in lower postprandial (after-meal) blood glucose levels. The drug works locally in the gastrointestinal tract with minimal systemic absorption, and its main therapeutic benefit is the reduction of post-meal glucose spikes.
ADMINISTRATION
Before taking acarbose, please consult with a healthcare professional. The following information is for general knowledge and should not be considered medical advice.
Acarbose tablets are intended for oral administration and are typically taken three times daily, at the beginning of each main meal. This timing helps the medication work effectively by slowing down the digestion of carbohydrates and managing the increase in blood sugar that follows a meal.
DOSAGE AND STRENGTH
Acarbose is available in oral tablet form in 25 mg, 50 mg, and 100 mg strengths. It is commonly prescribed to help manage blood sugar levels in individuals with type 2 diabetes and should be taken at the start of each main meal.
DRUG INTERACTIONS
Acarbose, used in the treatment of type 2 diabetes, may interact with other medications by altering blood sugar levels—either increasing or decreasing them. Additionally, it can impact the absorption or concentration of certain drugs, leading to potential changes in their effectiveness.
FOOD INTERACTIONS
Acarbose has important interactions with specific carbohydrates, sugars, and alcohol. Its effectiveness is also highly influenced by the timing of food intake. Because it works by slowing the digestion of carbohydrates, dietary adjustments are essential to enhance its benefits and reduce potential side effects.
CONTRAINDICATIONS
Acarbose is not recommended for patients with diabetic ketoacidosis, cirrhosis, inflammatory bowel disease, or intestinal obstruction. Since the drug acts within the gastrointestinal tract, it is also contraindicated in conditions that could be aggravated by increased gas production.
SIDE EFFECTS
Common Side Effects of Acarbose (Point-wise):
1. Flatulence (Gas) – Very common due to fermentation of undigested carbohydrates in the colon.
2. Abdominal discomfort or pain – Often mild to moderate.
3. Bloating – Caused by gas accumulation.
4. Diarrhea– Can occur as carbohydrates remain unabsorbed.
5. Soft stools – Related to altered digestion.
6. Nausea – Less common, usually mild.
7. Indigestion (Dyspepsia) – Possible due to slowed carbohydrate breakdown.
8. Elevated liver enzymes – Rare; usually reversible upon discontinuation.
9. Skin rash or allergic reactions – Uncommon but possible.
10. Hypoglycemia – Only when used with other antidiabetic drugs like insulin or sulfonylureas. In such cases, simple sugars (like glucose) should be used, not sucrose, which acarbose inhibits.
TOXICITY
Acarbose is generally regarded as safe, with its most common side effects being mild to moderate gastrointestinal issues. Serious adverse effects are rare and usually stem from idiosyncratic reactions. Since acarbose is minimally absorbed and acts mainly within the gastrointestinal tract, it has low systemic toxicity.
