1. Continuous IV infusion:  0.01 - 0.1 U/kg/hr (starting dose usually 0.05 U/kg/hr). Titrate infusion rate according to blood glucose response.

   Infusion should not be included in the daily prescribed fluid total.  Insulin should be given in addition to daily fluid intake.

   Insulin (units of 1 Unit/ml dilution) to be added to 50ml =

   50 x weight (kg) x dose (units/kg/hour)                    IV rate (ml/hr)

2. Intermittent dose: 0.1-0.2 U/kg 6-12 hourly SC/IM.

Indications

1. Hyperglycaemia in VLBW infants with persistent glucose intolerance.
2. Hyperkalaemia in critically ill VLBW infants.

Contraindications and Precautions

1. May rapidly induce hypoglycaemia.
2. Hypersensitivity to insulin (extremely rare).
3. Insulin resistance may develop causing a larger dose requirement.

Clinical Pharmacology

Insulin enhances uptake of glucose in insulin sensitive tissues, enhances glycogen and fat synthesis, enhances muscle uptake of amino acids and cellular uptake of potassium. It inhibits lipolysis and gluconeogenesis. Plasma half-life is short (approximately 9 minutes in adults), with degradation in liver and kidneys. Absorption from IM or SC doses is variable.

Possible Adverse Effects

1. Hypoglycaemia
2. Hypokalaemia

Special Considerations

1. If given by infusion, should be via a line that will not need to be flushed (to avoid boluses) and ideally the same line as is used for dextrose or intravenous nutrition infusion. This ensures cessation of insulin at the same time as glucose infusion if the drip tissues, and thus reduces the risk of hypoglycaemia.
2. Incompatible with aminophylline, chlorothiazide, dobutamine, lignocaine, phenobarbitone, phenytoin, sodium bicarbonate.
3. Effect decreased by drug-induced hyperglycaemia e.g. corticosteroids, thiazide diuretics, adrenaline, glucagon, thyroid preparations, phenytoin.
4. Adsorbs onto plastic i.e. syringes, extension tubing, filters, and 3-way taps.
5. Is considered safe by National Women’s Hospital Paediatricians to mix insulin and heparin in the same syringe for administration via a central venous line.