Comparative effects of pravastatin and lovastatin on nighttime sleep and daytime performance

Pravastatin and lovastatin, two HMG-CoA reductase inhibitors with similar cholesterol-lowering effects, differ in their lipid solubility. The hydrophilic characteristics of pravastatin may explain why the drug has not been detected in cerebrospinal fluid. On the other hand, lovastatin, a lipophilic compound, has been detected in the cerebrospinal fluid. Previous reports have suggested that lovastatin administration may be associated with insomnia, which reflects an action in the central nervous system. The effects of the two drugs on nocturnal sleep and day-time performance in young, healthy men have been assessed in randomized, double-blind, placebo-controlled studies. Computer-based performance tests were administered on two consecutive days before drug administration and at the end of a 3-week active drug or placebo treatment period. Results from both sites were combined for analysis. Neither pravastatin nor lovastatin significantly affected nocturnal sleep or daytime sleepiness in this study population, but lovastatin significantly affected daytime performance. In subjects treated with lovastatin, the results showed that two measures of performance, divided attention (p less than 0.05) and vigilance (p less than 0.01), worsened significantly from baseline as did global performance (p less than 0.01). Performance was not affected in the pravastatin and placebo groups. These results provide preliminary evidence of an adverse effect of lovastatin on daytime performance.