Phase I 1/2 evaluation and methodology of RO 20-2230 in postoperative patients

This report presents the rationale and methodology of our "phase 1 1/2" model for drug evaluation and reports the results of a typical study. We found that Ro 20-2230, and investigational agonist-antagonist analgesic, was well tolerated in therapeutic doses, with 15 mg intramuscular Ro 20-2230 approximately equivalent to 10 mg intramuscular morphine sulfate.