Glucose

• Hypoglycemia:
  • Treatment and prevention of acute hypoglycemia in patients with diabetes mellitus, especially those receiving insulin or oral hypoglycemic agents.
  • Used in mild to moderate symptomatic hypoglycemia to rapidly restore blood glucose levels.
• Parenteral Nutrition:
  • Source of carbohydrate calories in intravenous nutrition formulations.
  • Maintains blood glucose during periods of fasting or inability to eat.
• Diagnostic Use:
  • Oral glucose tolerance test (OGTT) for diagnosis of diabetes mellitus and gestational diabetes.
• Other Uses:
  • Treatment of low blood sugar during surgical procedures or critical illness.
  • Energy source during metabolic stress in hospitalized patients.

• Oral Administration:
  • For mild hypoglycemia, 15–20 grams of oral glucose (e.g., glucose tablets or gel) is recommended.
  • Repeat every 15 minutes as needed until blood glucose normalizes.
• Intravenous Administration:
  • For severe hypoglycemia or when oral administration is not possible:
  – Adults: 25–50 mL of 50% dextrose solution (D50) intravenously over 1–3 minutes.
  – Pediatrics: Dose adjusted according to weight, typically 0.5–1 g/kg (2–4 mL/kg of D25 or D50).
  • Continuous infusion dosing depends on clinical condition and glucose requirements.
• Special Populations:
  • Neonates: Use lower concentration dextrose solutions (D10–D12.5) due to risk of hyperosmolarity.
  • Elderly: Dose adjusted based on severity of hypoglycemia and comorbidities.
• Monitoring:
  • Blood glucose levels should be checked before and after administration to assess efficacy and avoid hyperglycemia.

Glucose is a simple monosaccharide that serves as a primary energy substrate for cellular metabolism. Upon administration, glucose is rapidly absorbed (oral route) or directly supplied (intravenous route) into the bloodstream, raising plasma glucose levels. This replenishment reverses the effects of hypoglycemia by providing immediate energy to glucose-dependent tissues such as the brain, muscles, and erythrocytes. Glucose metabolism involves glycolysis and oxidative phosphorylation, generating ATP essential for cellular functions and survival.

• Absorption:
  • Rapidly absorbed from the gastrointestinal tract when administered orally.
  • Intravenous administration bypasses absorption, delivering immediate systemic availability.
• Distribution:
  • Distributed throughout body fluids and tissues according to concentration gradients and cellular uptake.
  • Crosses the blood-brain barrier via facilitated diffusion.
• Metabolism:
  • Primarily metabolized in cells through glycolysis to pyruvate, entering the Krebs cycle for ATP production.
  • Excess glucose stored as glycogen in liver and muscle.
• Elimination:
  • Metabolized glucose is not excreted unchanged; however, excess glucose may be excreted in urine if renal threshold exceeded (glycosuria).
• Onset of Action:
  • Oral glucose: within 10–15 minutes.
  • IV glucose: within 1 minute.
• Half-life:
  • Plasma glucose half-life varies, as it is rapidly utilized by tissues; levels normalize depending on metabolic demand.

• Pregnancy:
  • Glucose is considered safe and essential during pregnancy for energy supply.
  • Used clinically in management of hypoglycemia in pregnant women and during labor.
• Lactation:
  • No safety concerns; glucose is a normal component of breast milk and safe during breastfeeding.

• Primary Class: Carbohydrate / Antihypoglycemic agent
• Subclass: Simple sugar / energy substrate

• Known hypersensitivity to glucose or components of the formulation (rare).
• Hyperglycemia or diabetic ketoacidosis without concurrent insulin therapy (due to risk of worsening hyperglycemia).
• Intracranial or intraspinal hemorrhage where increased glucose may exacerbate injury (caution advised).

• High-risk groups:
  • Diabetic patients require careful monitoring to avoid hyperglycemia.
  • Patients with impaired renal or hepatic function need close monitoring of glucose levels.
  • Risk of tissue necrosis if extravasation occurs during IV administration.
• Serious risks:
  • Hyperglycemia leading to osmotic diuresis, dehydration, electrolyte imbalance.
  • Local complications such as phlebitis or tissue damage from IV infusion.
• Monitoring:
  • Blood glucose, electrolytes, and acid-base balance during prolonged infusion.
  • Observation for signs of extravasation during IV administration.

• Common:
  • Hyperglycemia (if overdosed or in diabetics).
  • Local irritation, pain, or phlebitis at IV injection site.
  • Transient nausea or bloating after oral administration.
• Rare/Serious:
  • Extravasation injury causing tissue necrosis.
  • Electrolyte imbalances (e.g., hypokalemia) during prolonged high-dose infusions.
• Onset & Dose Dependence:
  • Side effects depend on dose and route; rapid IV administration increases risk of local irritation.

• Major Interactions:
  • Insulin and oral hypoglycemic agents: glucose administration counteracts their hypoglycemic effects.
  • Drugs affecting glucose metabolism (e.g., corticosteroids, beta-agonists) may alter glucose requirements.
  • No significant CYP450 enzyme involvement.
• Food Interactions:
  • None relevant; glucose itself is a dietary sugar.
• Alcohol:
  • Alcohol may impair gluconeogenesis, affecting glucose homeostasis.

• Clinical Guidelines:
  • Hypoglycemia management protocols consistently recommend oral glucose for mild cases and IV glucose for severe or unconscious patients.
  • Recent emphasis on patient self-management with glucose tablets or gels for rapid correction of hypoglycemia.
  • Parenteral glucose remains cornerstone in critical care for energy provision and metabolic support.
• Safety Warnings:
  • Updated guidelines stress prevention of extravasation injury during IV administration and monitoring of electrolytes during prolonged use.

• Store glucose preparations at 20°C to 25°C (68°F to 77°F).
• Protect from excessive heat, moisture, and light.
• Keep intravenous solutions sterile and discard unused portions after opening.
• Avoid freezing solutions to prevent crystallization.
• Keep out of reach of children.