倍他乐克系β1受体阻滞剂，而β1受体主要分布于心肌，所以，它还会直接或间接地抑制心肌细胞自产辅酶Q10。
服用倍他乐克，应补充辅酶Q10，老年人最好用有活性的还原型辅酶Q10，英文名 ubiquinol。 而且，不论辅酶Q10还是ubiquinol，不能一下子骤停，否则，心肌细胞突然的缺乏它，会导致症状复发或加重, 尤其对有心律失常的老年人。
Beta-Blockers And CoQ10 Deficiency
Beta-blockers have been shown to block the biological pathway of coenzyme Q10-dependent enzymes in the body.8 This interferes with energy production and protection against free radicals, contributing to fatigue.8,9 This drug-induced depletion may be particularly serious in the elderly, who already suffer from a natural age-related CoQ10 deficiency. CoQ10 is a mitochondrial enzyme essential for the production of adenosine triphosphate (ATP), the core of cellular energy processes.10-13 A 2009 clinical study showed a close correlation between lowered levels of CoQ10 and its role in the pathophysiology of chronic fatigue as a direct result of mitochondrial dysfunction.14
Levels of CoQ10 naturally decline with age. While adults over the age of 30 can benefit from taking CoQ10 supplements, they are especially important for people with cardiovascular concerns, and those who take certain blood pressure medications like beta-blockers.15-18 Ubiquinol (the active form of CoQ10) has a much greater bioavailability than ubiquinone (the oxidized form), helping to improve metabolic efficiency of the cardiovascular system to maintain heart health.19 Based on a meta-analysis of published scientific research, therapeutic doses of ubiquinol range between 100 to 200 mg daily, but may be increased if conditions warrant.9
http://www.lef.org/Magazine/2014/8/Beta-Blockers-Cause-Lack-Of-Restful-Sleep/Page-01
