Cardiovascular effects of levobunolol eyedrops in healthy subjects

The cardiovascular side effects of the abrupt cessation of treatment with 0.5% levobunolol hydrochloride eyedrops in 10 healthy subjects (5 women and 5 men) aged 18 to 30 years were investigated in a double-blind randomized crossover study. The subjects received either levobunolol eyedrops or placebo drops for 7 days, then, after a 14-day washout period, they received the alternative drops for 7 days. The heart rate and blood pressure at rest, the maximal heart rate and blood pressure on treadmill exercise stress testing and duration of exercise were recorded before treatment began, at the end of treatment and 14 days after withdrawal of the drops. The mean resting heart rate was significantly lower during treatment with levobunolol than with placebo (p less than 0.05). The mean exercise duration was significantly longer during treatment with levobunolol (p less than 0.05); to our knowledge, we are the first to report this finding. There were no significant differences in mean arterial pressure, double product (product of heart rate and systolic blood pressure) or maximal heart rate between the groups at any measurement.