Fatal rhabdomyolysis after acne therapy: A 20-year old was changed to the retinoid isotretinoin by mouth (40 mg/day; e.g. ISOTRETINOIN-RATIOPHARM), after he had tried various drugs against acne for two years without success. Several weeks later he complained of strong muscle pain after exertion during sporting activity which disappeared after using pain-relieving topical agents. Shortly afterwards, the young man's condition deteriorated increasingly during a demanding one month's Asian trip, during which isotretinoin intake was suspended, to the extent that he experienced respiratory problems when climbing stairs. On the trip home he needed a wheelchair at times. A few days after admission to hospital in Germany he died of heart failure with massive pulmonary oedema. Creatinine phosphokinase (CPK) level was extremely elevated at 82.000 U/l. The musculature appeared softened in places according to the autopsy report. The forensic expert attributed the death to very severe rhabdomyolysis caused by taking the long-acting isotretinoin and unaccustomed physical exertion (NETZWERK Report 16.080). Heavy physical exertion is also considered partly responsible for the rhabdomyolysis experienced by a 23-year old isotretinoin user, who had practised bodybuilding and weight lifting again for the first time on therapy four days prior to diagnosis (GUTTMAN-YASSKY, E. et al.: Int. J. Dermatol. 2003; 42: 499-500). Muscle pain occurs very common on isotretinoin. According to the Summary of Product Characteristics (SPC), elevated CPK values are rare and occur particularly after physical exertion (ratiopharm: SPC ISTOTRETINOIN-RATIOPHARM, as at Oct. 2010), but in the literature they are partly described as very common and may occur with and without muscle symptoms (KAYMAK, Y.: Int. J. Dermatol. 2008; 47: 398-401). Five reports of myopathy from Germany and nine from outside Germany, including two and eight on rhabdomyolysis respectively, are available to the German Federal Institute for Drugs and Medical Devices (BfArM), (BfArM: letter of 17 Feb. 2012). Further individual case reports on reversible muscle symptoms with muscle pain, muscular weakness and a "myopathic pattern" in needle electromyography support a connection with the retinoid (FIALLO, P. et al.: Arch. Dermatol. 1996; 132: 1521-2; HODAK, E. et al.: BMJ 1986; 293: 425-6; SARIFAKIOGLU, E. et al.; Eur. J. Dermatol. 2011; 21: 794-5). Acne patients, who are mostly young, should be advised not to take part in intensive sporting activity and to avoid potential myotoxic substances, including alcohol, during treatment with isotretinoin by mouth. If clinical signs of muscle damage, electromyography evidence to this effect or conspicuous CPK values occur, it is recommended that the retinoid is discontinued (CHRONI, E. et al: Drug Saf. 2010; 33: 25-34).