Drugs for Diabetes

Question 1

Biguanides (Metformin): Mechanism of Action

Answer 1

Increase insulin sensitivity at target tissues through activation of AMP activated protein Kinase – inhibition of gluconeogenesis and glycogenolysis

Question 2

Biguanides (Metformin): Effects

Answer 2

Metformin exerts its effect mainly by decreasing gluconeogenesis and by increasing peripheral utilisation of glucose; since it acts only in the presence of endogenous insulin it is effective only if there are some residual functioning pancreatic islet cells.

Question 3

Biguanides (Metformin): Side Effects

Answer 3

Abdominal pain; nausea; vomiting

Question 4

Sulphonylureas: (Gliclazide): Side Effects

Answer 4

Hypoglycemia

Weight gain

Question 5

Biguanides (Metformin): Drug Dose

Answer 5

500 mg 3 times a day with meals (Initially 500 mg once daily for at least 1 week, dose to be taken with breakfast, then 500 mg twice daily for at least 1 week)

Question 6

Sulphonylureas: (Gliclazide): Effects

Answer 6

The sulfonylureas act mainly by augmenting insulin secretion and consequently are effective only when some residual pancreatic beta-cell activity is present; during long-term administration they also have an extrapancreatic action

Question 7

Sulphonylureas: (Gliclazide): Cautions

Answer 7

Sulfonylureas should be avoided or a reduced dose should be used in severe hepatic impairment, because there is an increased risk of hypoglycaemia.

Jaundice may occur.
Sulfonylureas should be used with care in those with mild to moderate renal impairment, because of the hazard of hypoglycaemia

Question 8

Sulphonylureas: (Gliclazide): Drug Dose

Answer 8

Initially 40–80 mg daily, adjusted according to response, increased if necessary up to 160 mg once daily, dose to be taken with breakfast, doses higher than 160 mg to be given in divided doses; maximum 320 mg per day.