Known brand names include Lantus.
A long-acting (basal) insulin injected under the skin once a day at the same time. It gives steady background insulin for about a day with no pronounced peak, lowering blood sugar in adults and children with diabetes.
Insulin glargine does the job of the body's own insulin. It helps muscle and fat pull sugar out of the blood, and it signals the liver to stop making sugar. It also keeps the body from breaking down stored fat and protein and helps build new protein.
After it is injected under the skin, it is absorbed slowly, giving a fairly even level over a full day without a sharp peak. In a study, its effect often lasted through the full 24 hours that were measured, though timing varies between people and even in the same person. Too much insulin action drops blood sugar too low, the most common side effect of any insulin, and its long action can make recovery from a low slow. Like all insulins, it shifts potassium from the blood into cells, which can drop blood potassium to a dangerous level.
Insulin glargine is a long-acting insulin for type 1 and type 2 diabetes. In type 1 diabetes the body makes no insulin, and in type 2 the body does not use insulin normally, so sugar builds up in the blood. It is meant to improve blood sugar control by supplying a steady background level of insulin through the day.
It is used by adults and children, injected under the skin once a day at the same time each day. People with type 1 diabetes use it together with a short-acting insulin taken for meals. It is not given into a vein or through an insulin pump, and it is not mixed with other insulins. It is not recommended for treating diabetic ketoacidosis, a diabetes emergency.
Low blood sugar is the side effect people notice most. Redness, pain, itching, or skin changes where it is injected, weight gain, swelling, and rash also happen. The label treats severe low blood sugar as dangerous, and because it lasts so long, recovery from a low can be slow. It also warns about low potassium, serious allergic reactions, heart failure with certain diabetes pills, and mix-ups with fast-acting insulin.