PRECOSE
Clinical safety rating
cautionComprehensive clinical and safety monograph for PRECOSE (PRECOSE).
Comprehensive clinical and safety monograph for PRECOSE (PRECOSE).
Adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitusOff-label: Prevention of type 2 diabetes in patients with impaired glucose tolerance
Alpha-glucosidase inhibitor; competitively inhibits brush-border alpha-glucosidases in the small intestine, delaying carbohydrate digestion and reducing postprandial hyperglycemia.
| Metabolism | Not extensively metabolized; primarily excreted unchanged in the urine as active drug. Small fraction undergoes intestinal metabolism by digestive enzymes. |
| Excretion | Primarily excreted in feces (about 85%) as unchanged drug and metabolites, with less than 2% excreted renally as active metabolites. |
| Half-life | Terminal elimination half-life is approximately 2 hours for the parent drug, but clinical effect persists due to prolonged binding to intestinal alpha-glucosidases. |
| Protein binding | Low protein binding, approximately 5%, primarily to albumin. |
| Volume of Distribution | Volume of distribution is approximately 0.3 L/kg, indicating minimal distribution into tissues and predominantly confined to extracellular fluid. |
| Bioavailability | Oral bioavailability is low, approximately 2%, due to local action in the gastrointestinal tract and minimal systemic absorption. |
| Onset of Action | Onset of action occurs within 15-30 minutes after oral administration, corresponding to gastric emptying and arrival at small intestine. |
| Duration of Action | Duration of action is approximately 4-6 hours, covering postprandial glucose peaks after each meal. |
| Molecular Weight | 645.6 |
Initial: 25 mg orally three times daily with the first bite of each main meal; maintenance: 50-100 mg three times daily; maximum 100 mg three times daily.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment recommended for mild to moderate renal impairment. Contraindicated in severe renal impairment (eGFR <25 mL/min/1.73 m²). |
| Liver impairment | No dose adjustment recommended for mild hepatic impairment. Not studied in moderate to severe hepatic impairment (Child-Pugh B or C); avoid use. |
| Pediatric use | Not recommended for pediatric patients (safety and efficacy not established). |
| Geriatric use | No specific dose adjustment required; monitor renal function due to age-related decline. Start at low end of dosing range (25 mg three times daily). |
| 1st trimester | Insufficient human data; animal studies show no evidence of fetal harm. Avoid use unless clearly needed. |
| 2nd trimester | Insufficient human data; use only if potential benefit justifies potential risk to fetus. |
| 3rd trimester | Insufficient human data; consider potential risk of maternal hypoglycemia and altered glucose metabolism. |
Clinical note
Comprehensive clinical and safety monograph for PRECOSE (PRECOSE).
| Placental transfer | Unknown; molecular weight suggests possible transfer, but negligible systemic absorption limits exposure. |
| Breastfeeding | Excretion into human milk is unknown; due to low oral bioavailability of acarbose, minimal systemic absorption suggests low risk to infant. Use with caution. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | Pregnancy Category B. No evidence of teratogenicity in animal studies at doses up to 200 mg/kg/day (6-15 times human exposure). No adequate human studies; risk cannot be ruled out. |
| Fetal Monitoring | Monitor maternal blood glucose and hemoglobin A1c; fetal monitoring not specifically required; standard obstetric care. |
| Fertility Effects | No evidence of impaired fertility in animal studies. No human data. |
■ FDA Black Box Warning
None.
| Serious Effects |
Diabetic ketoacidosisCirrhosisInflammatory bowel diseaseColonic ulcerationPartial intestinal obstructionPredisposition to intestinal obstructionChronic intestinal diseases associated with marked disorders of digestion or absorptionConditions that may deteriorate as a result of increased gas formation in the intestine (e.g., large hernias)
| Precautions | Hypoglycemia: Acarbose does not cause hypoglycemia when used alone, but may increase risk when combined with sulfonylureas or insulin. Hypoglycemic episodes should be treated with glucose (dextrose), not sucrose., Hepatic injury: Rare cases of acute hepatitis, jaundice, and fulminant hepatic failure; monitor liver function tests., Renal impairment: Contraindicated in patients with CrCl <25 mL/min., Gastrointestinal effects: Frequently causes flatulence, diarrhea, and abdominal discomfort due to undigested carbohydrates; these effects may diminish with continued use. |
| Food/Dietary | Avoid sucrose and table sugar as they may worsen GI side effects. Dietary carbohydrates increase efficacy but also GI side effects. Precose alone does not cause hypoglycemia; however, if used with insulin or sulfonylureas, hypoglycemia must be treated with glucose (dextrose) because absorption of complex sugars and sucrose is inhibited. |
| Clinical Pearls | Precose (acarbose) is an alpha-glucosidase inhibitor that delays carbohydrate absorption. It is most effective for postprandial hyperglycemia. Must be taken with the first bite of each main meal. Avoid use in patients with inflammatory bowel disease, colonic ulceration, or partial intestinal obstruction. Can cause elevated liver enzymes; monitor LFTs every 3 months during first year. Hypoglycemia from other agents should be treated with glucose (not sucrose) because sucrase is inhibited. |
| Patient Advice | Take this medication with the first bite of each main meal. · If you experience low blood sugar, treat it with glucose tablets or milk, not fruit juice or regular soda. · Common side effects include flatulence, diarrhea, and abdominal pain, which often decrease with time. · Do not take this drug if you have severe kidney problems or certain bowel diseases. · Report any signs of liver problems (yellow skin/eyes, dark urine, abdominal pain) immediately. |
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