Oral hypoglycemics (drug interactions)

DEFINITION: Medications used for controlling blood sugar in persons with type 2 diabetes.

INTERACTIONS: Coenzyme Q10, dong quai, Ginkgo biloba, herbs and supplements, ipriflavone, magnesium, potassium citrate, St. John’s wort, vitamin B12

DRUGS IN THIS FAMILY: Acarbose (Precose), acetohexamide (Dymelor), chlorpropamide (Diabinese), glimepiride (Amaryl), glipizide (Glucotrol, Glucotrol XL), glyburide or glibenclamide (DiaBeta, Glynase, Micronase), metformin (Glucophage, Riomet), miglitol (Glyset), pioglitazone (Actos), rosiglitazone (Avandia), repaglinide (Prandin), tolazamide (Tolinase), tolbutamide (Orinase), troglitazone (Rezulin)

Vitamin B12

Effect: Supplementation Possibly Helpful

The biguanide oral hypoglycemic drugs metformin and phenformin can cause malabsorption of vitamin B12. In turn, this can lead to vitamin B12 deficiency. Taking vitamin B12 supplements should easily solve this problem. Vitamin B12 is an important nutrient for individuals taking oral hypoglycemics because it aids glucose metabolism. Additionally, a vitamin B12 deficiency can lead to an impaired awareness of hypoglycemia because it impacts the nervous system, so monitoring for signs of a deficiency is essential.

Coenzyme Q10 (CoQ10)

Effect: Possible Benefits and Risks

Studies suggest that the oral hypoglycemic drugs glyburide, phenformin, and tolazamide may inhibit the normal production of CoQ10. While there is no direct evidence that taking extra CoQ10 will provide any specific benefit, supplementing with CoQ10 may be beneficial.

There is some evidence that the use of CoQ10 improves fasting blood glucose levels and fasting insulin levels, as well as improves vascular function. However, one might also need to reduce one’s medication dosage. Some studies suggest that CoQ10 is particularly helpful for individuals with diabetes who also have fatty liver disease.

Ipriflavone

Effect: Might Require Reduction in Medication Dosage

There is some evidence that the supplement ipriflavone might increase blood levels of oral hypoglycemic drugs. This could lead to a risk of blood sugar levels falling too low. Persons taking oral hypoglycemic medications should not take ipriflavone without first consulting a physician. Ipriflavone also interferes with most medications processed in the liver, so consulting a doctor before use is advisable.

Magnesium

Effect: Might Require Reduction in Medication Dosage

Magnesium supplements interact in complex ways with oral hypoglycemics. Magnesium hydroxide supplementation can increase the absorption of the medications chlorpropamide and glipizide (and, by inference, other oral hypoglycemics), possibly requiring a dosage reduction. However, in individuals with hypoglycemia, magnesium can prevent low blood sugar, but in individuals with type two diabetes, magnesium may increase the risk of hypoglycemia. In some studies, magnesium has helped reduce insulin resistance when combined with oral hypoglycemics, and other data indicate that long-term glucose levels may benefit from magnesium supplementation.

Additionally, magnesium deficiencies can contribute to the risk of diabetic complications, so maintaining a proper balance is necessary.

Herbs and Supplements

Effect: Might Require Reduction in Medication Dosage

Meaningful preliminary evidence suggests that using the following herbs and supplements could improve blood sugar control and, thus, require a reduction in daily doses of oral hypoglycemic medication: aloe, chromium, fenugreek, ginseng, gymnema, and vanadium.

Weaker evidence suggests that the following herbs and supplements could potentially have the same effect under certain circumstances: Anemarrhena asphodeloides, arginine, Azadirachta indica, bilberry leaf, biotin, bitter melon, carnitine, Catharanthus roseus, Coccinia indica, conjugated linoleic acid, Cucumis sativus, Cucurbita ficifolia, Cuminum cyminum (cumin), Euphorbia prostrata, garlic, glucomannan, Guaiacum coulteri, Guazuma ulmifolia, guggul, holy basil, Lepechinia caulescens, lipoic acid, Medicago sativa (alfalfa), Musa sapientum L. (banana), niacinamide, nopal cactus, onion, Phaseolus vulgaris, Psacalium peltatum, Pterocarpus, Rhizophora mangle, saltbush, Spinacea oleracea, Tournefortia hirsutissima, Turnera diffusa, and vitamin E.

Potassium Citrate

Effect: Possible Harmful Interaction

Potassium citrate and other forms of citrate (such as calcium citrate and magnesium citrate) may be used to prevent kidney stones. These agents work by making the urine less acidic. This effect on the urine may lead to decreased blood levels and therapeutic effects of chlorpropamide and possibly other oral hypoglycemic drugs. For this reason, it may be advisable to avoid these citrate compounds during treatment with oral hypoglycemic drugs.

Ginkgo biloba

Effect: Possible Harmful Interactions

It has been suggested that ginkgo might cause problems for persons with type 2 diabetes, both by altering blood levels of medications and by directly affecting the blood-sugar-regulating system of the body. However, some well-designed studies have failed to find any such actions. As a precaution, people with diabetes should use ginkgo only under physician supervision.

Dong Quai, St. John’s Wort

Effect: Possible Harmful Interaction

Some oral hypoglycemic drugs have been reported to cause increased sensitivity to the sun, amplifying the risk of sunburn or skin rash. Because St. John’s wort and dong quai may also cause this problem, taking these herbal supplements during treatment with oral hypoglycemic drugs might add to this risk. It is advisable to wear sunscreen or protective clothing during sun exposure if one takes any of these herbs while using an oral hypoglycemic medication.

Bibliography

Chin-Yang, Ray, et al. "Hypoglycemia Associated with Drug–Drug Interactions in Patients with Type 2 Diabetes Mellitus Using Dipeptidylpeptidase-4 Inhibitors." Frontiers in Pharmacology, 15 Apr. 2021, doi.org/10.3389/fphar.2021.570835.

Hodgson, J. M., et al. “Coenzyme Q(10) Improves Blood Pressure and Glycaemic Control: A Controlled Trial in Subjects with Type 2 Diabetes.” European Journal of Clinical Nutrition, vol. 56, 2002, pp. 1137-42.

Kudolo, G. B., et al. “Short-Term Ingestion of Ginkgo Biloba Extract Does Not Alter Whole Body Insulin Sensitivity in Non-Diabetic, Pre-Diabetic, or Type 2 Diabetic Subjects.” Clinical Nutrition, vol. 25, 2006, pp. 123-34.

"Metformin (Oral Route)." Mayo Clinic, 1 Sept. 2024, www.mayoclinic.org/drugs-supplements/metformin-oral-route/precautions/drg-20067074. Accessed 20 Sept. 2024.

Nie, Ruifang, et al. “Ipriflavone as a Non-steroidal Glucocorticoid Receptor Antagonist Ameliorates Diabetic Cognitive Impairment in Mice.” AgingCell, vol. 21, no. 3, 2022, p. e13572, doi:10.1111/acel.13572.

Preston, Claire L. Stockley’s Drug Interactions. 12th ed., Pharmaceutical Press, 2021.

Pronsky, Z. M., and J. P. Crowe. Food Medication Interactions. 19th ed., Food-Medication Interactions, 2018.

Ting, R. Z., et al. “Risk Factors of Vitamin B12 Deficiency in Patients Receiving Metformin.” Archives of Internal Medicine, vol. 166, 2006, pp. 1975-79.