1. Clinical Overview
Dextrose 25% w/v is a sterile, hypertonic solution of dextrose monohydrate in water for injection, providing 25 grams of dextrose per 100 mL. It is a rapid source of carbohydrate calories and fluid. In clinical practice, it is primarily used for the rapid correction of hypoglycemia, as a source of calories in total parenteral nutrition (TPN), and for the management of hyperkalemia and cerebral edema when used in conjunction with insulin. Its hypertonic nature (approximately 1262 mOsm/L) mandates administration via a central venous catheter to avoid severe phlebitis and sclerosis of peripheral veins.
| Onset | Duration | Bioavailability |
|---|---|---|
| Immediate upon intravenous administration; blood glucose levels begin to rise within 5-10 minutes. | Variable, dependent on metabolic rate and insulin response; typically 30-60 minutes for glycemic correction, but caloric effects are utilized over hours. | 100% when administered intravenously. |
2. Mechanism of Action
Dextrose provides a readily metabolizable source of carbohydrate calories and water. It corrects hypoglycemia by directly increasing plasma glucose concentration. Its hypertonic nature creates an osmotic gradient, drawing fluid from the interstitial and intracellular compartments into the intravascular space, which is useful in managing cerebral edema (with insulin) and can transiently expand plasma volume. When combined with insulin for hyperkalemia, it promotes intracellular shift of potassium.
3. Indications & Uses
- Severe hypoglycemia (when oral correction is not possible)
- Source of carbohydrate calories in Total Parenteral Nutrition (TPN)
- Management of hyperkalemia (in combination with insulin)
- Management of cerebral edema (in combination with insulin, e.g., in hyperglycemic hyperosmolar state)
4. Dosage & Administration
Adult Dosage: Highly individualized. For hypoglycemia: 25-50 mL (6.25-12.5g dextrose) IV push, followed by infusion guided by glucose monitoring. For TPN: As part of a calculated daily caloric requirement, typically infused over 12-24 hours. For hyperkalemia: 25-50g (100-200 mL) with 10-20 units of regular insulin IV over 15-60 minutes.
Administration: STRICTLY FOR INTRAVENOUS USE ONLY. MUST be administered via a large-bore central venous catheter. Check for extravasation constantly. Do not administer simultaneously with blood through the same line (causes hemolysis). The solution is hypertonic and may be mixed with amino acids, lipids, and other TPN components. Infusion rate must be controlled by an infusion pump. Patient must be monitored for signs of infection, thrombosis, and metabolic complications.
5. Side Effects
Common side effects may include:
- Hyperglycemia
- Glycosuria (if renal threshold exceeded)
- Venous irritation/phlebitis (if given peripherally)
- Fluid overload (especially in susceptible patients)
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Insulin | Additive hypoglycemic effect; used therapeutically for hyperkalemia. Risk of severe hypoglycemia if not coordinated. | Major |
| Corticosteroids (e.g., Dexamethasone, Prednisolone) | May antagonize the glucose-lowering effect, leading to hyperglycemia. | Moderate |
| Thiazide and Loop Diuretics (e.g., Furosemide) | May impair glucose tolerance, potentiating hyperglycemia. | Moderate |
| Beta-blockers (e.g., Propranolol) | May mask tachycardia symptoms of hypoglycemia and impair glycogenolysis. | Moderate |
| Phenytoin | May be incompatible in same IV line; can precipitate. Phenytoin can also cause hyperglycemia. | Moderate |
7. Patient Counselling
- Do report any pain, redness, or swelling at the IV site immediately.
- Do inform all healthcare providers if you have diabetes.
- Do not attempt to adjust the infusion rate.
- Do not use if the solution is discolored or contains particles.
8. Toxicology & Storage
Overdose: Manifestations of overdose include severe hyperglycemia, hyperosmolarity, glycosuric osmotic diuresis leading to dehydration and electrolyte loss (K+, Na+, Mg++, PO4---), hyperosmolar hyperglycemic state (HHS), lactic acidosis, and fluid overload leading to pulmonary edema and heart failure.
Storage: Store at room temperature (not exceeding 30°C). Protect from freezing and excessive heat. Keep in the original outer carton to protect from light. Do not use if the container is leaking, damaged, or if the solution is cloudy, discolored, or contains any visible particles. Once the infusion bag/bottle is spiked, use promptly. Follow manufacturer's instructions for stability after opening.