INSULIN DOSAGE - PRACTICAL POINTS

CALCULATING AND ADJUSTING INSULIN DOSAGE:

TYPE 1 DIABETES MELLITUS: 0.3 - 0.7 Units/kg/day of insulin Ref. Harrison 21st Ed.

                                                         0.4 - 1.0 Units/kg/day Ref. ADA guidelines.

Higher amounts are required during puberty, pregnancy, medical illness.

Lower amounts are required in renal failure.

 Start at 0.5 U/kg/day (TDI - Total Daily Insulin)

                       ↓

50% of TDI as Basal     &    50 % of TDI as Prandial/Bolus/Nutritional Insulin

                       ↓

To this insulin Add Supplemental / correcting insulin based on Pre-prandial glucose

Correction factor/Insulin sensitive factor:  

         a) Body weight(kg) x (Actual Blood glucose - Desired Blood Glucose) ÷ 1500 = Units to be added /subtracted

(OR) b) 1 U of Insulin for every 30-60 mg/dl 

(OR) c) 1500 / TDI for Regular Insulin e.g., 1500/30U = 50U i.e., 1 U will reduce 50 mg/dl. 

             1800 / TDI for Rapid acting Insulin (Lispro, Aspart, Glulisine)

(OR) d) Insulin -to- carbohydrate ratio: 

              Lunch & Supper: 1 Unit Insulin / 10-15 g of Carbohydrate (CHO) 

              Breakfast: 1.5 U / 10 g of CHO Since growth hormone & cortisol levels are high at morning.

              (Must be determined for each individual). Ref. ADA.

Example:

 70 kg person requires TDI 

                  ↓

 0.5 x 60 = 30 U / day (TDI)

                  ↓

Basal (50%) 15 U + Prandial (50%) 15 U [e.g., R5 N5 - R5 - R5 N5]

                  ↓

If pre-lunch CBG is 250 mg/dl and Desired CBG is 180 mg/dl

correction factor = 60 x (250-180) ÷ 1500 ≈ 3 U i.e., R8 to be given before lunch

similarly, Morning and Night doses to be adjusted according to above formula

or Simply Titrate 2U every 3 days till target CBG goals achieved.

WHICH INSULIN TO BE ADJUSTED: (Ref. ADA)

If this glucose levels are out of target                  Adjust this insulin component

1.Post Breakfast / Pre-Lunch                   →          Pre-Breakfast Rapid/short Insulin

2.Post Lunch / Pre supper                        →          Pre-Lunch Rapid/short and/or Morning NPH                                                                                                                       

3.Mid Afternoon                                      →          Morning NPH or Long-acting insulin

4.Post supper / Bedtime                          →           Pre supper Rapid/short Insulin

5.Early Morning (FBS)                           →           Evening NPH or Long-acting insulin

TIMING OF INSULIN INJECTION:

Short acting insulin analogues -- Just before (< 10 Min) meals

Regular Insulin analogues -- 30-45 mins before meals

BLOOD GLUCOSE TARGETS:  

HBA1C: < 7.0 %

Fasting BG: 80 - 130 mg/dl

Post Prandial BG: < 180 mg/dl

NOTE: References: Harrison 21st Ed., Google scholars. 

The above mentioned are for educational purposes and not for patients use.

KINDLY E-MAIL IF ANY CORRECTIONS IN THE ABOVE