The possible nephrotoxicity of a bituminous coal dermatologic agent

: Nephrotoxic effects are discussed as a possible risk of dermatological coal tar preparations. Therefore, we have performed a renal tolerance study with a modern coal tar preparation for the scalp, Berniter. 15 healthy volunteers, randomly subjected to 3 different modes of application, applied the preparation: twice weekly (mode I) or daily (mode II) for a period of 8 weeks. In both modes, application time was 15 min. In mode III, the preparation was used under occlusion for 30 min every second day for a period of 4 weeks. Before, during and after treatment, renal functions and urinary phenol levels were assayed. No pathological change or impairment of renal functions was detected. A relationship between urinary phenol content and the coal tar treatment was not observed, either. We conclude that the coal tar preparation investigated here has no nephrotoxic properties.