RENAL + GU: GLUCOSE (DEXTROSE)

Question 1

GLUCOSE(DEXTROSE): INDICATIONS

Answer 1

• Glucose 5% is used to provide water intravenously in patients unable to take enough orally
• Glucose 10%, 20% and 50% are used to treat hypoglycaemia when this is severe or cannot be treated orally. Glucagon is an alternative
• Glucose 10%, 20% and 50% are used with insulin to treat hyperkalaemia. Calcium gluconate may also be given in this setting
• Glucose 5% is used for reconstitution and dilution of drugs intended for administration by injection or infusion. Sodium chloride 0.9% and sterile water are alternatives.

Question 2

GLUCOSE(DEXTROSE): MOA

Answer 2

• When given in a 5% solution, glucose is administered simply as a means of providing water intravenously (its calorific content is negligible)
• The glucose makes the solution initially isotonic and prevents it from inducing osmolysis
• Glucose is rapidly taken up by cells and metabolised, leaving ‘free’ (hypotonic) water that diffuses throughout all body water compartments
• As only about 7% of the administered volume remains in the intravascular space (since the intravascular compartment is about 7% of total body water), glucose is not a suitable fluid for expanding circulating volume.

Question 3

GLUCOSE(DEXTROSE): ADVERSE EFFECTS

Answer 3

• Glucose 50% is highly irritant to veins and may cause local pain, phlebitis and thrombosis
• Glucose 20% is also irritant, but less so.
• Hyperglycaemia will occur if glucose administration exceeds its utilisation (which is most likely in patients with diabetes mellitus)

Question 4

GLUCOSE(DEXTROSE): WARNINGS

Answer 4

• In patients at risk of thiamine deficiency, giving IV glucose can cause Wernicke’s encephalopathy
• If IV glucose treatment is needed, thiamine (as Pabrinex®) must also be given
• In renal failure, close monitoring of fluid balance is essential to avoid overload
• Administering a significant volume of hypotonic fluid to a patient with hyponatraemia (or more susceptible to its effects, e.g. children) may precipitate hyponatraemic encephalopathy.

Question 5

GLUCOSE(DEXTROSE): INTERACTIONS

Answer 5

• Glucose and insulin have antagonistic effects.
• Concurrent administration may nevertheless be appropriate, as in intravenous insulin infusions, for example.
• However, the rate of glucose infusion should ideally be kept constant unless treatment for hypoglycaemia is required.

Question 6

GLUCOSE(DEXTROSE): EXAMPLES

Answer 6

• glucose 5%
• glucose 10%
• glucose 20%
• glucose 50%