<qa>  What is the maximum dose of morphine?METHODSDESIGN: Prospective, double blind, randomized clinical trial. Adult ED patients between the ages of 18 and 65 years of age in whom the attending ED physician has decided to administer parenteral opiates, will be randomized to receive either 0.1 mgkg IV morphine maximum dose of 10 mg or 0.15mgkg IV morphine maximum dose of 15 mg. An on-line random plan generator will be used to generate an allocation schedule. The allocation schedule will be fully documented with the reference citation of the pseudo-random number generator, the seed used to start the generation process, the number of treatments 2, the allocation ratio 1:1, the size and number of blocks, and a copy of the assignment list. The allocation schedule will be given to the Montefiore Department of Pharmacy where it will be used to determine the content of consecutively numbered vials with either the study doses of morphine. The Pharmacy Department will prepare and handle the vials in accordance with known stability data and labeled with expiration dates. They will provide the study with labeled packages containing the numbered vial, a label with the vial number to be attached to the patients data collection instrument, an opaque envelope with the assignment group identified to be used in the event of a clinical emergency that requires immediate determination of what the patient received and a weight based dosing schedule for morphine. All patients will receive a bolus of morphine 0.1mgkg at time 0. At 30 minutes, patients will receive the study drug which will contain either an additional 0.05mgkg of morphine or placebo. After the initial morphine bolus and study drug, patients will have received either morphine 0.1 mgkg maximum of 10 mg or 0.15 mgkg maximum of 15mg. 