Hydralazine (drug interactions)

DEFINITION: Medication that causes dilation of the walls of blood vessels and is sometimes used to treat hypertension, diuretic resistance, and edema.

INTERACTIONS: Coenzyme Q10, Coleus forskohlii, vitamin B6

TRADE NAME: Apresoline

Vitamin B6

Effect: Supplementation Likely Helpful

Hydralazine is known to deplete the blood of vitamin B6, causing a deficiency. Taking vitamin B6 supplements, particularly the 4-methanol form called Pyridoxine, may prevent or reverse the side effects of the medication. Physicians sometimes prescribe vitamin B6 supplements with hydralazine to treat numbness, tingling, and burning sensations that sometimes occur as a result of the medication.

Coenzyme Q10 (CoQ10)

Effect: Supplementation Possibly Helpful

There is some evidence that hydralazine might impair the body’s ability to manufacture the substance CoQ10. This suggests (but does not prove) that taking CoQ10 supplements may produce a beneficial effect.

Coleus forskohlii

Effect: Theoretical Interaction

The herb Coleus forskohlii relaxes blood vessels and might have unpredictable effects if combined with hydralazine.

Other Interactions

Hydralazine has several other drug interactions of which patients should be aware. The supplements melatonin, zinc, calcium, and ephedra also interact with hydralazine. One major drug interaction occurs with the muscle relaxer tizanidine, which could cause an unsafe drop in blood pressure when taken with hydralazine. Patients taking monoamine oxidase inhibitors (MAOI) for depression while receiving diazoxide injections should also not take hydralazine. Patients with some medical issues, such as coronary artery diseases, renal dysfunction, or cerebral vasculopathy, should also avoid taking hydralazine. Hydralazine increases the effect of angiotensin-converting enzyme (ACE) inhibitors, calcium channel blockers, and vasodilators. Patients taking hydralazine should also avoid alcohol, as severe reactions may occur.

Bibliography

Brunton, Laurence L., et al., editors. Goodman and Gilman’s the Pharmacological Basis of Therapeutics. 14th ed., McGraw-Hill Medical, 2023.

Crooks, Frank, and Ryan Raman. “Hydralazine Side Effects, Dosage, Uses & More.” Healthline, 7 Feb. 2018, www.healthline.com/health/drugs/hydralazine-oral-tablet#interactions. Accessed 21 Aug. 2023

Garrison, Kelli. "Hydralazine - Uses, Side Effects, and More." WebMD, 3 June 2024, www.webmd.com/drugs/2/drug-8662/hydralazine-oral/details. Accessed 20 Sept. 2024.

“Hydralazine Interactions Checker.” Drugs.com, 2023, www.drugs.com/drug-interactions/hydralazine.html. Accessed 21 Aug. 2023.

Kishi, H., et al. “Bioenergetics in Clinical Medicine: Inhibition of Coenzyme Q10 Enzymes by Clinically Used Anti-Hypertensive Drugs.” Research Communications in Chemical Pathology and Pharmacology, vol. 12, no. 3, 1975, pp. 533-40.

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

Tucker, Katherine, et al. Modern Nutrition in Health and Disease. 12th ed., Jones & Bartlett Learning, 2024.