Medication Treatment of Diabetes Mellitus

People with type 1 diabetes almost always require insulin therapy and will become very sick without it. Many people with type 2 diabetes require insulin as well. Usually, insulin is injected under the skin. For certain people, inhaled insulin is also available, although it is not used commonly. Insulin currently cannot be taken by mouth because insulin is destroyed in the stomach. New forms of insulin, such as forms that can be taken by mouth, are being tested.

Insulin is injected under the skin into the fat layer, usually in the arm, thigh, or abdomen. Small syringes with very thin needles make the injections nearly painless.

An insulin pen, which contains a cartridge that holds the insulin, is a convenient way for many people to carry and use insulin, especially for people who take several injections a day outside the home.

Another device is an insulin pump, which pumps insulin continuously from a reservoir through a small cannula (hollow plastic tube) left in the skin. The rate of insulin administration can be adjusted depending on the time of day, whether the person is exercising, or other parameters. People can release additional doses of insulin as needed for meals or to correct high blood glucose levels. The pump more closely mimics the way the body normally produces insulin. Pump therapy is considered in some people who require more than three injections per day. For some people, the pump offers an added degree of control, whereas others find wearing the pump inconvenient or develop sores at the needle site.

Hybrid closed-loop insulin-delivery systems are also available. With these systems (sometimes called an artificial pancreas), an algorithm is used to calculate and automatically deliver baseline insulin doses through an insulin pump based on input from a continuous glucose monitor. However, this device does not eliminate the need for people to monitor their blood glucose levels and give themselves insulin before meals.

Oral antihyperglycemic medication can often lower blood glucose levels adequately in people with type 2 diabetes Type 2 diabetes Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more . However, they are not effective in type 1 diabetes Type 1 diabetes Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more . There are several types, but oral antihyperglycemic medications work in four major ways:

Insulin secretagogues include sulfonylureas (for example, glyburide, glipizide, and glimepiride) and meglitinides (for example, repaglinide and nateglinide).

Insulin sensitizers include biguanides (for example, metformin) and thiazolidinediones (for example, pioglitazone).

Medications that delay absorption of glucose by the intestine include alpha-glucosidase inhibitors (for example, acarbose and miglitol).

Medications that increase glucose secretion in the urine include sodium-glucose co-transporter-2 (SGLT2) inhibitors (for example, canagliflozin, dapagliflozin, and empagliflozin).

Dipeptidyl peptidase-4 (DPP 4) inhibitors (for example, sitagliptin, saxagliptin, linagliptin, and alogliptin) both stimulate the pancreas to produce more insulin and delay the absorption of glucose by the intestine. These medications work by increasing glucagon-like peptide 1 (GLP-1).

People with type 2 diabetes are often prescribed oral antihyperglycemic medications if diet and exercise fail to lower the levels of glucose in the blood adequately. The medications are sometimes taken only once a day, in the morning, although some people need two or three doses. More than one type of oral medication, and/or an oral medication plus insulin or an injectable glucagon-like peptide 1 (GLP-1) medication or dual incretin agonist, may be used if one medication is not adequate.

Insulin Insulin Replacement Therapy Many people with diabetes require medication to lower blood glucose levels, relieve symptoms, and prevent complications of diabetes. There are two types of diabetes mellitus Type 1, in which... read more is the most commonly used injectable antihyperglycemic medication. Its use is discussed above.

There are two other types of injectable antihyperglycemic medications:

Injectable antihyperglycemic medications are given together with other antihyperglycemic medications.

Glucagon-like peptide medications (GLP-1 medications) work mainly by increasing insulin secretion by the pancreas. These medications also slow the passage of food out of the stomach (which slows the rise of blood glucose), and reduce appetite and promote weight loss. GLP-1 medications are given by injection. The most common side effects are nausea and vomiting. These medications may increase the risk of pancreatitis Overview of Pancreatitis Pancreatitis is inflammation of the pancreas. The pancreas is a leaf-shaped organ about 5 inches (about 13 centimeters) long. It is surrounded by the lower edge of the stomach and the first... read more (a painful inflammation of the pancreas), although the evidence is unclear. They should not be used in people with a personal or family history of medullary thyroid cancer Medullary thyroid cancer The cause of thyroid cancer is not known, but the thyroid gland is very sensitive to radiation, which may cause cancerous changes. Thyroid cancer is more common among people who were treated... read more , because studies in animals showed an increased risk of some types of thyroid tumors. So far, data from large clinical trials has not shown an increase in these types of cancers in humans.

Tirzepatide is a medication that acts on both GLP-1 receptor (like the GLP-1 medications) and also acts on another receptor called glucose insulinotropic polypeptide (GIP) receptor that also affects insulin secretion and weight loss. This medication can also be used in people who have type 2 diabetes and obesity.

Amylin-like medications mimic the action of amylin, a pancreatic hormone that helps regulate blood glucose levels after eating. Pramlintide is currently the only available amylin-like medication. It suppresses secretion of the hormone glucagon. Because glucagon increases blood glucose, pramlintide thus helps lower blood glucose. It also slows the passage of food out of the stomach and helps people feel full. It is given by injection and is used in combination with mealtime insulin in people with type 1 or type 2 diabetes.

Because people with diabetes mellitus are at risk of complications, such as heart attacks Acute Coronary Syndromes (Heart Attack; Myocardial Infarction; Unstable Angina) Acute coronary syndromes result from a sudden blockage in a coronary artery. This blockage causes unstable angina or a heart attack (myocardial infarction), depending on the location and amount... read more and strokes Overview of Stroke A stroke occurs when an artery to the brain becomes blocked or ruptures, resulting in death of an area of brain tissue due to loss of its blood supply (cerebral infarction) and symptoms that... read more , it is important that people take medications to prevent or treat these complications. Unless there is a reason people cannot take one of these medications (for example, an allergy to the medication), they may be given the following:

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