Insulin Type
Synonyms
Retardant
Time of Effect Hours Onset Peak Duration
Unmodified
SolubleRegular
None
0.25-1H] P] sameB
1.5-4
5-9
NPH
Isophane
Protamine
0-5-2H]P] sameB]
3-6
8-14
Lente
Mixture of 30% Semilente (an amorphous precipitate of Insulin with Zinc ions) with 70% Ultralente Insulin
Zinc
H 1-2P 1-2B 1-5-3
3-83-85-10
7-147-1610-24
Ultralente
An Insoluble Crystal of Zinc and Insulin
Zinc
H 2-3B 3-4
4-86-12
8-1412-28
Insulin Analogues
Lispro
None
5-15 Minutes
1-2
4-5
Premixed
10/9025/7530/70 and 50/50
Protamine
0.25-1.5
3-6
8-14
Insulin regimens
Once daily regimenIt is most commonly used in type 2 diabetes patients with secondary failure to OHA and used in combination with OHA. Either lente, ultralente, or NPH is used. NPH is preferred before breakfast, whereas lente or ultralente before dinner. The regimen is not suitable for type 1 diabetes cases.
Twice daily regimen It is the most commonly used regimen as it is suitable for most type l, 2, and GDM patients. It is very convenient as patient has to take only BBF and before dinner (BD) dose and there is no need to carry insulin to school or office. Usually both short and long acting insulins are used in combination, but in few cases only long acting insulin can be used alone but not the short acting. This regimen is not to be used in acute medical emergencies. Usually, of the total daily dose 2/3rd is given BBF and 1/3rd before dinner; but depending upon eating habits and glycaemic status, dose can vary and even 50 percent can be given BBF and BD. Again, the usual ratio of long acting to short acting is 2/3:1/3 or 70:30. But in premixed insulins wide range is available from 10:90, 25:75 to 50:50. This regimen gives similar results as compared to multiple injections or CSII by pump.
Basal bolus regimenIn this regimen regular and intermediate acting insulin is used. Basal requirement is met by intermediate acting insulin given twice a day before breakfast and dinner. The regular insulin is given before each meal thrice a day. Out of the total daily requirement 50 percent is given as basal (intermediate) and 50% as regular insulin. The share of regular insulin (50%) is given as 20% BBF, 10% BL and 20% BD. It gives similar results as compared to twice a day but the only disadvantage is that the before lunch (BL) dose is to be taken at school or office.
Continuous subcutaneous insulin infusion Only short acting insulin is used and is given by insulin pump that the patient has to wear throughout the day. It is neither practical, nor are the results better than twice daily or bolus regimen.
Insulin therapy for ketoacidosis
The use of low dose insulin regimen either given by insulin infusion or intramuscularly is now the accepted regimen for keto-acidosis. The high dose regimen is no longer used, as with low dose regimen there is less frequent hypokalemia, hypoglycemia, and more predictable response.
Insulin is given as 6 u/hour by continuous IV infusion. Only short acting insulin is used. When the blood sugar falls to 250 mg% the normal saline is replaced with 10% dextrose and insulin infusion rate reduced to 4 u/hour. But if significant drop in plasma glucose is not observed after 2 hours of insulin infusion and if fluid replacement, blood pressure, and infusion lines are satisfactory, then double the infusion rate.
Insulin can be given by IM route with dose of 6 u/hr but often a loading does of 20 u is required. If after 2 hours the fall in sugar is not satisfactory, either double the dose or start IV infusion. The acidosis and ketosis resolve more slowly than hyperglycemia; hence, IV dextrose preferably 10% dextrose with insulin should continue till patient starts eating and shift to thrice a day regimen by subcutaneous route. It is advisable to increase the total daily dose by 20 prcent of previous (before onset of ketoacidosis) insulin dose and after recovery discharge on previous or twice a day regimen.
Insulin regimen in special group of patients
Elderly: Do not aim for strict glycemic control. Twice a day or once a day regimen are most suitable.
Renal failure: There is considerable reduction in insulin requirement and twice daily or basal bolus regimens are suitable.
Recurrent hypoglycemia: Insulin dose distribution needs to be reviewed rather than the regimen. In some cases shifting evening dose to bedtime can prevent nocturnal hypoglycemia.
Children: Same regimens are used as for adults. Intermediate insulin may be absorbed faster. Twice a day is best suited as it eliminates injection at school.
Secondary diabetes: Due to pancreatic disease; usually have mild diabetes and can be managed with twice a day regimen.
Steroid and endocrine diabetes: They have marked insulin insensitivity and considerable endogenous insulin secretions. It may require high dose of insulin, but cessation of steroids often allows patient to come off insulin again. They are managed with twice daily regimen. Endocrinopathies cause mild diabetes that can be easily controlled with twice a day insulin regimen.
Pregnancy: Insulin dose will increase as pregnancy advances and balance of insulin changing to greater daytime requirement. There is sudden fall in insulin requirement after delivery.
Cirrhosis of liver: Marked insulin insensitivity during day but because of impaired gluconeogenesis, no difficulty in maintaining glucose concentration over night. Hence require preprandial injection regimen.