Which insulin is never mixed with other insulins ?
**Core Concept**
Insulin mixtures and analogs have unique properties that require careful handling and administration. The type of insulin being mixed can affect its pharmacokinetics and pharmacodynamics, making it essential to understand which insulins can be mixed and which should not be combined.
**Why the Correct Answer is Right**
The correct answer is a long-acting insulin analog, specifically glargine insulin. This type of insulin is designed to provide a steady release of insulin over a long period, typically 24 hours or more. Mixing glargine insulin with other insulins can alter its release profile and lead to unpredictable glucose control. This is because glargine insulin forms a depot in the subcutaneous tissue, which can be disrupted when mixed with other insulins, affecting its absorption and action.
**Why Each Wrong Option is Incorrect**
**Option A:** Short-acting insulins like aspart (NovoLog) can be mixed with other insulins, but they should not be mixed with long-acting insulins like glargine.
**Option B:** NPH insulin (Humulin N) is an intermediate-acting insulin that can be mixed with short-acting insulins, but it should not be mixed with long-acting insulins like glargine.
**Option C:** Regular insulin (Humulin R) is a short-acting insulin that can be mixed with other insulins, but it should not be mixed with long-acting insulins like glargine.
**Clinical Pearl / High-Yield Fact**
When mixing insulins, it's essential to use the same type of insulin vial (e.g., regular or NPH) and to rotate the vials to prevent contamination. Always check the label to ensure that the insulins are compatible for mixing.
**Correct Answer:** C. Regular insulin (Humulin R) is a short-acting insulin that can be mixed with other insulins, but it should not be mixed with long-acting insulins like glargine.