Insulin
- Indications for insulin
- All patients with Type 1 Diabetes (T1DM)
- Patients that presents with diabetes and a HbA1C ≥ 9.0% AND signs/symptoms of complications
- Patients that fail maximal OGLA therapy
- Patients admitted with DKA or HHS
- Disadvantages of insulin
- Painful injection
- Issues with compliance
- Risk of hypoglycemia (self-monitoring of blood glucose should be done at least 4 times a day incliding before each meal and before bed)
- Must be aware of one’s diet and exercise (involves using a glucometer)
- Expensive (a whole moral quandary)
- Blood glucose targets for patients on insulin
- 5 – 7 mmol/L on waking
- 4 – 7 mmol/L before meals at other times of the day
Insulin formulations
| Formulation | Examples | Nota bene |
|---|---|---|
| Rapid-acting | Lispro, aspart, glulisine | Typically given before meals |
| Short-acting | Regular insulin, NPH/regular preparations (75/25, 70/30, 50/50) | |
| Intermediate-acting | Non-proteated Hagedorn (NPH) | First-line insulin. May be prescribed along-side soluble insulin seperately or as pre-mixed solution. |
| Long acting | Detemir, glargine | Typically given in the morning or night. Alternative to NPH in patients who have recurrent hypoglycaemic episodes or require reduced injections |
Once-daily Basal Insulin Regimen
10 IU insulin detemir or 10 IU insulin glargine can be given in the morning OR at night (usually at night). Preferred to use insulin detemir since Insulin glargine has carcinogenic effects)
Twice-daily Basal Insulin Regimen
NPH/regular combinations, including 70/30 preparation in the morning AND 50/50 preparation in the evening
- Daily dosage: 0.5 U/kg
- 2/3 of the daily dosage in units is given in the morning (70/30 or 75/25 preparation)
- 1/3 of the daily dose in units is given in the evening (50/50 preparation)
- Calculate the Twice-daily basal insulin regimen dosage for Mr. Wepukhulu who weighs 112 kg
- Total units: 56 U (112kg x 0.5 U/kg = 56 U)
- Morning units: 37 U of 70/30 preparation
- Evening units: 19 U of 50/50 preparation
Basal-bolus “Prandial” insulin regimen
The patient takes a long-acting insulin in the morning or at night and rapid-acting insulin before each main meal (breakfast, lunch, dinner). The patient should check blood glucose before injecting themselves with rapid insulin.
- Dosage
- Long-acting: 10 U insulin glargine OR insulin detemir in the morning or at night
- Short-acting: 0.1 – 0.3 U/kg of insulin glulisine, insulin lispro, or insulin aspart 15 minutes before meals
Sliding Scale Insulin Regimen
Useful in hospital, particularly because patients have active inflammatory processes or infections which may dramatically alter blood glucose levels. Short-acting insulin is given at scheduled times (q6h, q4h, etc) and dosing is based on the patient’s glucose levels. Would be the ideal insulin regimen but would require a lot of discipline from the patient. Happens automatically in patients with insulin pumps. Know that sliding-scale insulin protocols exist.
