Overview
Which Insulins May Share a Syringe
A mixed insulin dose combines two prescribed insulin actions in one subcutaneous injection.
A mixed insulin dose combines two prescribed insulin actions in one subcutaneous injection. The usual compatible pairing is a rapid-acting insulin analogue with intermediate-acting NPH insulin, but only when the exact products are approved for mixing. Do not decide compatibility from appearance. “Clear” means the insulin is in solution; it does not mean that it can safely be combined with every other clear insulin. NPH is cloudy because it is a suspension. Its particles settle during storage and must be redistributed before the dose is measured. Mixing is not a way to make insulin stronger. It is a way to deliver the prescribed mealtime effect of the rapid insulin and the later effect of NPH in one injection. Combining unapproved products can alter the intended insulin action, produce an unreliable dose, or contaminate a vial. Humalog® U-200 must never be mixed with another insulin product. If the prescription, product labelling, concentration, or combination is uncertain, stop and clarify before preparing the dose.