insulins

what is novorapid?

• rapid-acting insulin analogue

• recombinant human insulin with a single amino acid substitution (proline at B28 replaced with apartic acid)

• allows faster absorption from subcutaneous tissue

describe the pharmacology of insulin glargine

• binds to insulin receptors (tyrosine kinase receptors) on target cells (muscle, adipose tissue, liver)

• this causes autophosphorylation of the receptor, activation of intracellular signalling pathways

• increases glucose uptake in muscle and adipose tissue

• decreases hepatic glucose production and increases glycogen synthesis

describe the pharmacokinetics of novorapid

• onset in 10-20 mins

• peak action in 1-3 hours

• duration 3-5 hours

what medicinal forms is insulin glargine available in?

• solution for injection

what are the important side-effects of insulin glargine?

• hypoglycaemia

• weight gain

• injection-site reactions

• oedema

• lipodystrophy (if injection sites not rotated)

what are the important drug interactions for insulin glargine?

• other antidiabetics, ACE-inhibtors and alcohol - increased risk of hypoglycaemia

• corticosteroids, thiazide diuretics - decrease hypoglycaemic effects

• beta-blockers may mask symptoms of hypoglycaemia

what advice would you give to a patient taking novorapid?

• 15 minutes before or 10 minutes after a meal

• dose may need adjusting depending on amount of carbohydrates in your meal

• ensure they know the symptoms of hypoglycaemia and have a source of glucose on hand

• carry a card with up-to-date insulin information

what are the cautions for insulin glargine?

• higher risk of hypoglycaemia - missed meals, alcohol intake or increased physical activity

• renal or hepatic impairment

• elderly patients

• intercurrent illness or stress

what is lantus?

• recombinant human insulin analogue

• asparagine at A21 replaced by glycine, two arginine residues added to the B-chain

• formulated at acidic pH and precipitates in subcutaneous tissue, releasing insulin slowly and steadily

describe the pharmacokinetics of lantus

• onset 1-2 hours

• no pronounced peak

• duration 24 hours

what advice would you give to a patient taking lantus?

• inject once daily, at the same time everyday

• rotate injection sites, use a new needle each time and make sure insulin is clear and colourless

• be aware of the symptoms of hypoglycaemia

• check blood glucose as advised

• do not stop lantus even if you aren’t eating, check blood glucose more regularly