Generic Name

Tolbutamide

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Classification

FDA Approved Indications

• Management of type 2 diabetes mellitus

Mechanism of Action

Stimulates insulin release from pancreatic beta cells by inhibiting ATP-sensitive potassium channels, leading to increased insulin secretion.

Dosage and Administration

Adult: Typically 500 mg once daily initially, titrated up based on response, with usual doses between 500-2000 mg per day in divided doses.

Pediatric: Not commonly used in pediatric patients; consult specific pediatric guidelines.

Geriatric: Start at low doses due to potential increased sensitivity and comorbidities.

Renal Impairment: Use with caution; dosage adjustments may be necessary.

Hepatic Impairment: Use with caution; monitor liver function.

Pharmacokinetics

Absorption: Well absorbed from gastrointestinal tract.

Distribution: Widely distributed; crosses into placenta and breast milk.

Metabolism: Metabolized in the liver.

Excretion: Excreted mainly in urine as metabolites.

Half Life: Approximately 4-6 hours.

Contraindications

• Known hypersensitivity to sulfonylureas or sulfonamides.
• Type 1 diabetes mellitus.
• Diabetic ketoacidosis.

Precautions

• Use with caution in renal or hepatic impairment.
• Risk of hypoglycemia; monitor blood glucose regularly.
• Pregnancy category C; consider risks and benefits in pregnancy and lactation.

Adverse Reactions - Common

• Hypoglycemia (Common)
• Gastrointestinal discomfort (nausea, epigastric pain, heartburn) (Uncommon)

Adverse Reactions - Serious

• Severe hypoglycemia (Rare)
• Hematologic reactions (leukopenia, aplastic anemia) (Very rare)
• Dermatologic reactions (rash, erythema, Stevens-Johnson syndrome) (Rare)

Drug-Drug Interactions

• Other antidiabetic agents (risk of hypoglycemia), beta-blockers (mask hypoglycemia symptoms), NSAIDs (alter glucose levels).

Drug-Food Interactions

• Alcohol (may increase hypoglycemia risk).

Drug-Herb Interactions

N/A

Nursing Implications

Patient/Family Teaching

• Take medication as prescribed. Monitor blood sugar levels regularly.
• Recognize symptoms of hypoglycemia (sweating, trembling, weakness) and how to treat it.
• Maintain a balanced diet and adhere to exercise recommendations.
• Inform healthcare provider of all medications and supplements.

Special Considerations

Black Box Warnings:

• Risk of severe and prolonged hypoglycemia in certain populations.

Genetic Factors: Limited data.

Lab Test Interference: May affect certain blood glucose and HbA1c measurements.

Overdose Management

Signs/Symptoms: Severe hypoglycemia, including dizziness, confusion, seizures, loss of consciousness.

Treatment: Immediate administration of oral glucose or IV dextrose; patient may require hospitalization for monitoring and supportive care.

Storage and Handling

Storage: Store at room temperature away from moisture, heat, and light.

Stability: Stable under recommended storage conditions for the shelf life indicated on the packaging.