Synopsis
Match insulin pharmacology and delivery to glucose patterns, titrate safely, and prevent hypoglycaemia, ketoacidosis, device and concentrated-insulin errors.
- Rapid-acting analogues cover meals and corrections; short-acting human insulin has slower onset and longer meal-related action, so timing is not interchangeable.
- Intermediate NPH and long- or ultra-long analogues provide basal insulin; basal controls fasting hepatic glucose output and must not be used repeatedly to correct post-meal excursions.
- Basal–bolus multiple daily injection is the standard flexible regimen for most adults with type 1 diabetes; pump and hybrid closed-loop options require structured training and backup plans.
Key red flags
Falling glucose overnight or between meals, recurrent fasting lows and a need to snack without hunger suggest basal dose exceeds background requirement, especially after weight or renal change.
Investigation priorities
Link fasting, meals, exercise and overnight patterns to each insulin component.
Management branches
Confirmed insulin-deficient type 1 diabetes requiring lifelong insulin.
- Offer structured education and multiple daily basal–bolus injections using analogue insulin, or assess pump and hybrid closed-loop eligibility and preference through the specialist service.
- Teach carbohydrate ratios, correction sensitivity, active insulin, injection or infusion technique, ketone rules, hypoglycaemia, exercise, alcohol, driving and backup supplies.
Key medicines
Rapid-acting insulin analogueDose before or with meals using the trained carbohydrate ratio and correction plan.
Long-acting basal insulin analogueGive once or twice daily at the individually titrated consistent time.