Methyldopa is a medication that is sometimes used to control hypertension; however, it is not a first-line treatment due to the various health risks associated with its use.
There is some evidence that methyldopa might impair the body's ability to manufacture the substance coenzyme Q 10 (CoQ 10 ). 1 Taking CoQ 10 supplements might make sense as a general precaution, but no specific benefit has been established.
Iron supplements can interfere with the absorption of methyldopa, so make sure you do not take iron during the 2 hours before or after your methyldopa dose. 2,3
References
REF1 Kishi H, et al. Bioenergetics in clinical medicine. III. Inhibition of coenzyme Q 10 -enzymes by clinically used anti-hypertensive drugs. Res Commun Chem Pathol Pharmacol 12(3): 533–540, 1975.
REF2 Campbell NR and Hasinoff BB. Iron supplements: A common cause of drug interactions. Br J Clin Pharmacol 31: 251–255, 1991.
REF3 Campbell N, Paddock V, and Sundaram R. Alteration of methyldopa absorption, metabolism, and blood pressure control caused by ferrous sulfate and gluconate. Clin Pharmacol Ther 43: 381–386, 1988.