Approximately half of these 75 patients (45.3 %) had one or more of the following contributive factors: incorrect posology; previous or concomitant liver disorders with potential effect on the drug metabolism; concomitant treatments (CYP3A4 inhibitors; other drugs known to produce rhabdomyolysis), and other rhabdomyolysis etiologies (Table 2). This evidence concerns the gene CYP3A4 and rhabdomyolysis.