Never share an injection pen, cartridge, or syringe with another person, even if the needle has been changed.
Before taking this medicine
You should not use  Humulin R (Concentrated) if you are allergic to insulin, or if you are having an episode of hypoglycemia (low blood sugar).
Tell your doctor if you have ever had:
liver or kidney disease; or
low levels of potassium in your blood (hypokalemia).
Tell your doctor if you also take pioglitazone or rosiglitazone (sometimes contained in combinations with glimepiride or metformin). Taking certain oral diabetes medicines while you are using insulin may increase your risk of serious heart problems.
Tell your doctor if you are pregnant or breastfeeding.
Follow your doctor's instructions about using insulin if you are pregnant or you become pregnant. Controlling diabetes is very important during pregnancy, and having high blood sugar may cause complications in both the mother and the baby.
