[1] Univ Basel Hosp, Div Clin Pharmacol, Basel Pharmacoepidemiol Unit, CH-4031 Basel, Switzerland
[2] Univ Basel Hosp, Div Dermatol, CH-4031 Basel, Switzerland
[3] Univ Basel, Dept Pharm, Inst Pharmacotherapy, CH-4003 Basel, Switzerland
[4] Boston Univ, Sch Med, Boston Collaborat Drug Surveillance Program, Lexington, MA USA