by Kathy Karas, RPh. 

The first class of medications used for the treatment of diabetes are the sulfonylureas which have been available since 1954. The sulfonylureas work by stimulating insulin release from the Beta cells of the pancreas. They have also been shown to reduce glucose output from the liver and increase tissue sensitivity to insulin, which are probably indirect effects resulting from the decrease in blood glucose. Sulfonylureas are categorized as first generation-Orinase, Tolinase, Diabinese, and Dymelor second generation-Micronase, Diabeta, Glynase, and the most common adverse reaction is hypoglycemia.

This actually occurs more often in elderly patients (because they skip meals), malnourished individuals and patients who have abnormalities of the liver. kidney, or adrenal >glands. Also, alcohol ingestion, and an increase in exercise can trigger hypoglycemia. Glyburide (Micronase and Diabeta) and Diabinese have longer duration’s of action and are more likely to cause hypoglycemia.

If you have symptoms of low blood glucose such as shakiness, sweating, or rapid heart beat, test your glucose level. If it is below 70mg/dl, take a quick acting source of glucose such as 15gm of sugar, 1/2 cup of orange juice, or 3 glucose tablets. Antacids, H2 blockers (Tagamet), proton pump inhibitors (Prilosec), Lopid, and propoxyphene (the active ingredient in Darvocet) may also increase the hypoglycemic effect of sulfonylureas. High doses of aspirin and such medications as Aleve, Motrin, and Ibuprofen can also cause hypoglycemia.  Caffeine, Lasix, and calcium channel blockers can possibly cause hyperglycemia. (and please do not stop taking your medications, always monitor your blood glucose levels and let your MD know if there is a sudden increase or decrease in your blood glucose levels). Other adverse effects of the sulfonylureas include:

1.       GI disturbances such as constipation, diarrhea, heartburn, nausea, vomiting and a sensation of stomach fullness.

2.       Photosensitivity-use a sunscreen with at least a SPF of 15.

3.       A mild rash, itching or hives which usually disappears after taking the medication for a few weeks.

4.       Weight gain- why it is important to adhere to a strict diet.

Glucotrol should be taken 30 minutes before meals due to its impaired absorption when given with food. The XL formulation can be taken with a meal. The dose range of Glucotrol is 2.5MG to 40 MG daily or divided twice daily. Glyburide can be dosed from 1.25MG to 20MG daily or divided twice daily while Amaryl can be dosed from 1 to 8 mg. daily with the first main meal of the day. Ideal candidates for sulfonylurea therapy include patients recently diagnosed with diabetes as well as patients who are less than 50% above ideal body weight. Also, patients having fasting blood glucose levels between 180 and 200 and have some Beta cells that produce some insulin are good candidates.  Some common causes of failure of therapy by sulfonylureas include:

1.       Patient related factors such as overeating, stress, lack of physical activity and poor patient compliance,

2.       Disease related factors such as non-functioning Beta cells or an increase in insulin resistance, and

3.       Inadequate drug dosage or an impaired absorption of the drug due to hypoglycemia.