How Antidiabetes Drug Glyburide Interacts with Herbs
As the number of people with diabetes increases, so does the number of those who try alternative means to manage the disease, and that includes the use of herbs. A new study has examined how the diabetes drug glyburide (also known as glibenclamide) interacts with herbs, providing information for people with type 2 diabetes who use herbal remedies.
How does glyburide interact with herbs?
The researchers, who conducted the study at Grace College of Pharmacy in India, noted that 80 percent of the world's population uses herbal remedies, yet "western-trained physicians are poorly experienced regarding herbal remedies and lack the knowledge on benefit and risk ratio." Therefore, many individuals may be taking herbs without knowing how they could interact with their diabetes medication.
Similarly, there may be unrealized benefits people can enjoy by using certain herbs with diabetes drugs. Therefore, the authors reviewed the literature on the interactions of glibenclamide (name of the drug in India; known as glyburide in the US) with a variety of herbs. Here's a brief review of some of their findings.
- Ginger (Zingiber officinale). A mouse study revealed that a combination of ginger and glibenclamide significantly reduced nonfasting blood glucose by about 25%, which was better than use of the drug alone (7.9%)
- Prickly pear cactus (Opuntia ficus-indica and other species). While rats with diabetes have showed a possible lower blood glucose level when given prickly pear cactus extract, a few studies have indicated hypoglycemia (abnormally low blood sugar) as a side effect when prickly pear cactus was used along with oral antidiabetic drugs.
- Ginkgo biloba. Results of a double-blind study of type 2 diabetic patients who were taking oral antidiabetes drugs plus Ginkgo biloba for three months noted that patients experienced significant worsening of glucose tolerance and an increase in glucose level when combining the herb and medication.
- Gymnema sylvestre. Use of this herb along with antidiabetes drugs has shown the herb can improve glucose control with few side effects. One study even showed that 5 of 22 type 2 diabetes patients who were taking antidiabetes drugs were able to stop the drugs and completely rely on Gymnema sylvestre. Some trials, however, have shown that Gymnema sylvestre plus an antidiabetes drug can cause hypoglycemia.
- Ivy gourd (Coccinia indica). Ivy gourd has been used mainly in Ayurvedic medicine to treat diabetes. In a double-blind, placebo-controlled trial of 60 people with newly diagnosed type 2 diabetes, half the patients were given 1 gram of Coccinia indica extract per day for 90 days while the other half received placebo. Patients in the herbal group showed a significant decline in fasting blood glucose and hemoglobin A1c compared with the placebo group. Although a study using a combination of ivy gourd and an antidiabetes drug has not been reported, an earlier study compared use of the herb against the diabetes drug chlopropamide and found glycemic control to be similar between the two groups.
Some of the other herbs examined in the review included aloe vera, Azadirachta indica, Cassia auriculata, Momordica charantia (bitter melon), and Pleurotus pulmonarius. Notably missing were studies on cinnamon and curcumin.
The authors of this review emphasize that the "western world should take initiative in systematic evaluation of the combination effect of herbal remedies and drugs." If you take glyburide or other antidiabetes drugs and either use herbs or are considering doing so, do your homework and also look for healthcare providers who can help you.
Rai A et a. Interaction of herbs and glibenclamide: a review. ISRN Pharmacology 2012; 659478
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