Calcium channel blockers (drug interactions)

DEFINITION: Medications used to treat hypertension, angina, heart arrhythmia, and other heart-related conditions.

INTERACTIONS: Calcium, Ginkgo biloba, naringin (a citrus bioflavonoid), vitamin D, and many others

DRUGS IN THIS FAMILY: Amlodipine (Norvasc), diltiazem (Cardizem, Cardizem CD, Cardizem SR, Dilacor XR, Tiamate, Tiazac), felodipine (Plendil), isradipine (DynaCirc, DynaCirc CR), nicardipine hydrochloride (Cardene, Cardene SR), nifedipine (Procardia, Procardia XL, Adalat, Adalat CC), nimodipine (Nimotop), nisoldipine (Sular), verapamil (Calan, Calan SR, Covera-HS, Isoptin, Isoptin SR, Verelan)

Calcium and Vitamin D

Effect: Possible Decreased Action of Drug

Taking calcium and vitamin D supplements might interfere with some of the effects of calcium channel blockers.

Ginkgo biloba

Effect: Possible Decreased Action of Drug

According to a study in rats, ginkgo extract may cause the body to metabolize some calcium channel blockers more rapidly, thereby decreasing their effects.

Naringin (Citrus Bioflavonoid)

Effect: May Necessitate Reduction in Drug Dosage

Some evidence suggests that the bioflavonoid naringin may interact with medications in the calcium channel blocker family, increasing the drug's blood levels. This may necessitate a reduction in drug dosage.

Several other herbs and natural supplements may interfere with calcium channel blockers. St. John’s wort may decrease their effectiveness. When taken with calcium channel blockers, hawthorn may lower blood pressure to dangerous levels. Ginseng, magnesium, and goldenseal may interact adversely with calcium channel blockers. It is also important to remember that other prescription medications may also interact with calcium channel blockers. Patients taking statins, antifungals, antibiotics, and antiarrhythmic medications should talk with their healthcare provider. Finally, grapefruit juice can also interfere with the breakdown of calcium channel blockers in the body. 

Bibliography

Begum, Jabeen. "Calcium Channel Blockers for High Blood Pressure: Types, Uses, Effects." WebMD, 18 Dec. 2023, www.webmd.com/hypertension-high-blood-pressure/treatment-calcium-channel. Accessed 6 Sept. 2024.

"Calcium Channel Blockers - StatPearls." NCBI, 22 Feb. 2024, www.ncbi.nlm.nih.gov/books/NBK482473. Accessed 6 Sept. 2024.

Guadagnino, V., et al. "Treatment of Severe Left Ventricular Dysfunction with Calcium Chloride in Patients Receiving Verapamil." Journal of Clinical Pharmacology, vol. 27, 1987, pp. 407-409.

Horowitz, B. Zane. "Calcium Channel Blocker Toxicity." Medscape, 4 Apr. 2023, emedicine.medscape.com/article/2184611-overview. Accessed 6 Sept. 2024.

Kuhn, M., and D. L. Schriger. "Low-Dose Calcium Pretreatment to Prevent Verapamil-Induced Hypotension." American Heart Journal, vol. 124, 1992, pp. 231-232.

Luscher, T. F., et al. "Calcium Gluconate in Severe Verapamil Intoxication." New England Journal of Medicine, vol. 330, 1994, pp. 718-720.

Margolis, K. L., et al. "Effect of Calcium and Vitamin D Supplementation on Blood Pressure." Hypertension, vol. 52, 2008, pp. 847-855.