T2D Medicine Sulfonylurea (Glipizide)

Submitted by Thiruvelan on Wed, 06/23/2010
T2D Medicine Sulfonylurea (Glipizide)

Sulfonylurea diabetes medication helps the body to make more insulin; this excess insulin helps to lower the blood-glucose level when needed, especially after food time.

Sulphonylureas are also calling as Insulin Secretagogues; it stimulates insulin secretion. It can lower your blood glucose levels by increasing insulin secretion from the pancreatic beta cells. The liver metabolized Sulfonylurea and cleared by the kidney; use it cautiously in patients with hepatic or renal impairment.

Sulfonylureas mechanism of action

Sulfonylureas bind with an ATP-dependent K+ channel on the cell membrane of pancreatic beta cells. It inhibits hyperpolarizing outflux of potassium, causing electric potential over the membrane to become more positive. This depolarization opens voltage-gated Ca2+ channels. The rise in intracellular calcium leads to increased fusion of insulin granulae with the cell membrane, and therefore, increased secretion of (pro) insulin.

Sulfonylureas also sensitize beta cells to glucose; they limit glucose production in the liver, decrease breakdown and release of fatty acids by adipose tissue (lipolysis) and decrease clearance of insulin by the liver.

Sulphonylurea diabetes medications

  • Generic name: Chlorpropamide - Brand name: Diabinese – It is the only first-generation sulphonylureas in the market. It has more side effects than other sulfonylureas. And its use is no longer recommendable.
  • Generic name: Glipizide - Brand name: Glucotrol, Glucotrol XL, Minidiab,
  • Generic name: Glyburide or glibenclamide - Brand name: Diabeta, Glynase, and Micronase in the United States - Daonil, Semi-Daonil, and Euglucon in the United Kingdom - Delmide in India - DiaBeta, Euglucon in Canada.
  • Generic name: Glimepiride (Brand name: Amaryl, GLIMPID, GLIMY)
  • Generic name: Gliclazide (Brand name: Glizid, Glyloc, and Reclide in India; Diamicron, Diamicron MR in Canada and Australia; Diamicron MR in the Philippines. Many generic equivalents are also available, e.g., Glubitor-OD, Clizid.
  • Available only in a generic form: Tolazamide, Tolbutamide

Sulphonylurea dosage

  • Chlorpropamide – start with a minimum dose of 125 mg every morning, maximum dose 500 mg every morning, duration very long. It is no longer recommendable because of its extremely long half-life.
  • Glibenclamide or glyburide – start with a minimum dose of 2.5 mg every morning and a maximum dose of 10 mg twice daily.
  • Gliclazide – treat with a minimum dose of 40 mg every morning, maximum dose 160 mg twice daily, duration medium. The extended-release form has a minimum dose of 30 mg every morning, a maximum dose of 120 mg every morning, duration long.
  • Glipizide (Minidiab) – start with a minimum dose of 2.5 mg every morning, maximum dose 10 mg twice daily, duration medium.
  • Glimepiride (Amaryl) – begin with a minimum dose of 1 mg every morning, maximum dose 6 mg every morning, duration long.

There is a lower risk of hypoglycemia with glimepiride and gliclazide MR.

What can you expect for Sulphonylureas?

Sulfonylurea as a mono-therapy can reduce HbA1c levels by 1 to 2%, fasting plasma glucose (FPG) by 60 to 70 mg/dl (or 3.333 mmol/l to 3.889 mmol/l) or up to 25%. You can use sulfonylureas alone or in combination with most other oral diabetes drugs, and insulin. However, do not use it in conjunction with glinides or two SUs.

Who can benefit from Sulphonylureas?

Patients who respond well to sulfonylureas include those;

  • who diagnosed before 40 years of age,
  • duration of disease less than five years
  • before initiation of drug therapy and
  • a fasting blood glucose level of below 300 mg/dL (16.7 mmol/l).

Possible side effects of Sulfonylurea

Some of the common side effects of Sulfonylurea are low blood glucose (or hypoglycemia), upset stomach, skin rash, and Weight gain.

Who should avoid using Sulphonylurea?

Avoid Sulfonylurea, if you are allergic to sulfa drugs, pregnant (or planning to get), or breast-feeding.

  • It increases insulin secretion and therefore, increases hypoglycemia risk. The risk is higher in renal impairment, liver cirrhosis, and in the elderly.
  • It increases appetite and thus promotes weight gain.
  • They are contraindicating in patients known to be allergic to sulpha drugs.