Glucotrol XL (glipizide) is an extended-release oral antihyperglycemic agent indicated as an adjunct to diet and exercise for the management of type 2 diabetes mellitus. As a second-generation sulfonylurea, it facilitates glucose regulation by stimulating insulin secretion from functional pancreatic beta cells. Its unique gastrointestinal therapeutic system (GITS) delivery mechanism ensures a consistent 24-hour plasma concentration, supporting stable blood glucose levels with once-daily dosing. This formulation is designed for patients requiring pharmacological intervention beyond lifestyle modifications alone.

Features

• Active ingredient: Glipizide (5 mg or 10 mg)
• Formulation: Extended-release tablet utilizing GITS technology
• Dosing frequency: Once daily
• Onset of action: Within 2–3 hours post-administration
• Duration: Up to 24 hours of consistent glycemic effect
• Administration: Oral, with breakfast or first main meal

Benefits

• Provides sustained 24-hour glycemic control through advanced extended-release technology
• Reduces fasting and postprandial blood glucose levels effectively
• Lowers HbA1c by approximately 1–2%, supporting long-term metabolic health
• Minimizes peak-trough fluctuations, reducing risk of hypoglycemic events compared to immediate-release formulations
• Supports adherence through convenient once-daily dosing regimen
• Compatible with metformin for combination therapy when monotherapy is insufficient

Common use

Glucotrol XL is primarily prescribed for adults with type 2 diabetes mellitus who have not achieved adequate glycemic control through diet and exercise alone. It is suitable for both monotherapy and combination regimens with other antihyperglycemic agents, particularly metformin, when additional glycemic control is required. The medication is generally indicated for patients with residual pancreatic beta-cell function and is not appropriate for type 1 diabetes or diabetic ketoacidosis management.

Dosage and direction

Initial dosing typically begins with 5 mg once daily, administered with breakfast or the first main meal of the day. Dosage adjustments should be made in increments of 5 mg at weekly intervals based on blood glucose response. The maximum recommended daily dose is 20 mg. Elderly patients, those with hepatic impairment, or individuals with renal insufficiency (GFR <50 mL/min) should initiate therapy at 2.5 mg daily with careful monitoring. Tablets must be swallowed whole and not crushed, chewed, or divided, as this disrupts the extended-release mechanism.

Precautions

Regular monitoring of blood glucose and HbA1c is essential throughout therapy. Patients should be educated about recognizing and managing hypoglycemia, particularly during dose initiation, changes in meal patterns, or increased physical activity. Hepatic and renal function should be assessed periodically, as impaired clearance may increase hypoglycemia risk. Glucotrol XL may cause hemolytic anemia in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Use with caution in debilitated, malnourished, or elderly patients who may be more susceptible to hypoglycemia.

Contraindications

Glucotrol XL is contraindicated in patients with known hypersensitivity to glipizide, other sulfonylureas, or any component of the formulation. It is contraindicated in type 1 diabetes mellitus, diabetic ketoacidosis, with or without coma, and severe renal or hepatic impairment. Concomitant use with bosentan is contraindicated due to increased risk of hepatotoxicity.

Possible side effects

• Common (≥1%): Hypoglycemia, dizziness, nausea, headache, tremor
• Less common (0.1–1%): Gastrointestinal disturbances, skin reactions including pruritus and erythema
• Rare (<0.1%): Hematologic effects (leukopenia, thrombocytopenia), hyponatremia, syndrome of inappropriate antidiuretic hormone secretion (SIADH)
• Serious but rare: Hepatic porphyria, disulfiram-like reactions, severe cutaneous adverse reactions (SCARs) including Stevens-Johnson syndrome

Drug interactions

• Enhanced hypoglycemic effect: NSAIDs, salicylates, sulfonamides, chloramphenicol, probenecid, MAO inhibitors, beta-blockers
• Reduced hypoglycemic effect: Thiazides, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel blockers, isoniazid
• Other significant interactions: Warfarin (altered anticoagulant effect), alcohol (may cause disulfiram-like reaction)

Missed dose

If a dose is missed, it should be taken as soon as remembered on the same day. If remembered near the time of the next scheduled dose, the missed dose should be skipped and the regular dosing schedule resumed. Doubling doses is not recommended due to increased hypoglycemia risk.

Overdose

Sulfonylurea overdose produces profound hypoglycemia, which may manifest as sweating, tremor, blurred vision, and altered mental status progressing to seizures, coma, and cardiovascular collapse. Management requires immediate glucose administration (oral or intravenous depending on consciousness level) and continuous monitoring for at least 24–48 hours, as hypoglycemia may recur. Hospitalization is typically necessary for severe cases.

Storage

Store at controlled room temperature (20–25°C or 68–77°F) in the original container. Protect from moisture, light, and excessive heat. Keep out of reach of children. Do not use if the tablet is broken or damaged, as this compromises the extended-release properties.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Glucotrol XL is a prescription medication that should be used only under the supervision of a qualified healthcare provider. Individual response to therapy may vary, and treatment decisions should be based on professional medical evaluation. Patients should not adjust dosage or discontinue medication without consulting their physician.

Reviews

Clinical studies demonstrate Glucotrol XL’s efficacy in reducing HbA1c by 1.5–2.0% from baseline when used as monotherapy. The extended-release formulation shows comparable efficacy to immediate-release glipizide with significantly reduced hypoglycemia incidence (p<0.05). Patient satisfaction surveys indicate preference for once-daily dosing and reduced gastrointestinal side effects compared to immediate-release formulations. Long-term observational data support maintained efficacy over 12 months of treatment in compliant patients.