Grond, S Serum concentrations of tramadol enantiomers during patient-controlled analgesia. [electronic resource] - British journal of clinical pharmacology Aug 1999 - 254-7 p. digital Publication Type: Clinical Trial; Journal Article; Randomized Controlled Trial ISSN: 0306-5251 Standard No.: 10.1046/j.1365-2125.1999.00986.x doi Subjects--Topical Terms: AdultAgedAnalgesia, Patient-ControlledAnalgesics, Opioid--bloodBiotransformationDouble-Blind MethodFemaleGas Chromatography-Mass SpectrometryHumansHysterectomyLaparotomyMiddle AgedPain, Postoperative--drug therapyStereoisomerismTramadol--blood