Articles

Bioenergetics in clinical medicine. III. Inhibition of coenzyme Q10-enzymes by clinically used anti-hypertensive drugs.

Author

Kishi H

Date

1975

Journal

Res Commun Chem Pathol Pharmacol

Abstract

Background data revealed that some American and Japanese patients with essential hypertension, including many who were not being treated with any anti-hypertensive drug, had a deficiency of coenzyme Q10. Eight clinically used anti-hypertensive drugs have now been tested for inhibition of two mitochondrial coenzyme Q10-enzymes of heart tissue, succinoxidase and NADH-oxidase. Diazoxide and propranolol significantly inhibited the CoQ10-succinoxidase and CoQ10-NADH-oxidase, respectively. Metoprolol did not inhibit succinoxidase, and was one-fourth as active as propranolol for inhibition of NADH-oxidase. Hydrochlorothiazide, hydralazine, ans clonidine also inhibited CoQ10-NADH-oxidase. Reserpine did not inhibit either CoQ10-enzyme, and methyldopa was a very eak inhibitor of succinoxidase. The internationally recognized clinical side-effects of propranolol may be due, in part, to inhibition of CoQ10-enzymes which are indispensable in the bioenergetics of cardiac function. A pre-existing deficiency of coenzyme Q10 in the myocardium of hypertensive patients could be augmented by subsequent treatment with propranolol, possibly to the "life-threatening" state described by others.