Diabetes Mellitus

Question 1

How is therapeutic insulin administered?

Answer 1

Subcutaneous injection (upper arm/thigh/buttocks/abdomen)
-IV infusion for emergency treatment

Question 2

Why can’t insulin be given orally?

Answer 2

Insulin is a protein so would be digested in the gut

Question 3

How do you slow insulin absorption?

Answer 3

Due to short t1/2 (don’t want to give regularly)

• add protamine or zinc: forms complex with natural insulin (bovine/porcine)
• soluble insulin forms hexamers delaying absorption (plasma conc greatest after 2-3 hrs, dosing 15-30 mins before meal)

Question 4

What are the adverse effects of therapeutic insulin?

Answer 4

• hypoglycaemia

- lipodystrophy (due to regular injections into the same site)

Question 5

What are the contraindications of therapeutic insulin?

Answer 5

Renal impairment (hypoglycaemia risk)

Question 6

What are some drug interactions with therapeutic insulin?

Answer 6

• dose needs to increase with systemic steroids

- caution with other hypoglycaemic agents