Human Insulin + Insulin Isophane
Overview
Insulin Isophane + Human Insulin is a premixed insulin formulation that combines soluble (short-acting) human insulin with isophane (intermediate-acting) insulin. The soluble component acts quickly to manage post-prandial blood sugar spikes, while the isophane component is absorbed more slowly, providing longer-lasting basal coverage. This combination allows patients to manage both immediate and extended insulin needs with fewer injections compared to separate insulins. It is commonly used in both type 1 and type 2 diabetes to simplify insulin therapy.
Background and Date of Approval
This combination of human insulin and NPH insulin has been widely used for decades in diabetes management. The human insulin component is produced via recombinant DNA technology, making it structurally identical to endogenous insulin. Regulatory approvals for this combination exist worldwide, with formulations available in fixed ratios such as 30/70, 40/60, or 50/50 to balance prandial and basal insulin requirements. Clinical studies have demonstrated the efficacy and safety of premixed formulations for maintaining glycemic control in adults with diabetes.
Uses
Insulin Isophane + Human Insulin is indicated for the treatment of both type 1 and type 2 diabetes mellitus. It is used in patients who require both rapid prandial insulin and intermediate basal coverage but prefer a simplified dosing regimen. The combination is typically administered once or twice daily depending on individual patient needs and blood glucose monitoring results.
Administration
The insulin is administered subcutaneously in areas such as the abdomen, thigh, buttocks, or upper arm, and injection sites should be rotated to avoid lipodystrophy. Being a cloudy suspension, the vial or pen must be gently rolled to mix before each injection. Dosing is individualized based on body weight, blood glucose levels, and meal patterns, generally ranging from 0.3 to 1.0 IU per kg per day. The injection is usually given 30 minutes before meals to ensure the rapid-acting component matches the post-prandial glucose rise.
Side Effects
The most common side effect is hypoglycemia (low blood sugar). Other side effects may include weight gain, injection-site reactions such as redness or swelling, and potential lipodystrophy if injection sites are not rotated properly.
Warnings
Severe hypoglycemia can occur if doses are mismatched to meals or if carbohydrate intake is inconsistent. Rapid reductions in blood glucose can cause hypokalemia. Allergic reactions are rare but possible. Because of the intermediate-acting component, absorption may vary, and careful monitoring is required when switching from other insulin types or initiating therapy.
Precautions
Patients with renal or hepatic impairment may require lower doses because insulin clearance is reduced, increasing hypoglycemia risk. Consistency in meal timing and carbohydrate intake is critical due to the dual-action profile. Other glucose-lowering medications should be monitored and adjusted to prevent hypoglycemia. Proper storage in a cold chain is essential to maintain insulin potency.
Expert Tips
Educate patients on correct injection technique and resuspension of the cloudy insulin. Emphasize meal timing, typically injecting 30 minutes before food, to align the rapid-acting component with meals. Rotate injection sites to prevent lipodystrophy. Monitor glucose closely when initiating therapy or switching regimens, and titrate conservatively in patients with kidney or liver impairment.