[1] Azienda Unita Sanit Locale Parma, Serv Tossicodependenze, Ctr Studi Farmacotossicodipendenze, I-43100 Parma, Italy
[2] Osped Parma, Nucl Med Serv, Parma, Italy
[3] Osped Parma, Lab Anal Chim Clin, Parma, Italy
[4] Univ Parma, Ist Clin Med Gen, I-43100 Parma, Italy