Atorvastatin and gemfibrozil alter zebrafish behavior

The pharmaceuticals atorvastatin and gemfibrozil are prescribed for the treatment of high blood cholesterol. Atorvastatin has been detected in surface waters at a concentrations of 250 ng/L while gemfibrozil at 0.5 μg/L. We tested the effects of atorvastatin and gemfibrozil individually and in combination on the swimming behavior and response of zebrafish (Danio rerio) to a conspecific alarm cue. We also measured whole-body cortisol and the effect of the alarm on metabolic rate. Fish exposed to nominal concentrations of 0.075 and 7.5 μg/L atorvastatin showed exaggerated responses to the alarm. In contrast, a high gemfibrozil concentration (nominal: 250 μg/L) alone and in combination with atorvastatin inhibited the alarm response suggesting an antagonistic effect. Neither drug affected total cortisol. After exposure to the alarm chemical the metabolic rate of control fish increased, but all other treatments decreased. This study shows that these drugs can effect behaviour at environmentally relevant concentrations.