For severe pain from a significant burn, sickle cell crisis, fracture, or other injury, morphine is an excellent choice The usual dosage of morphine is 0.1 to 0.2 mg/kg/dose, titrated to effect and given intravenously over a few minutes The maximum dose is generally 10 mg for opioid-naive subjects, although starting doses of to mg for adolescents are usually sufficient if the medication is titrated upward based on pain symptoms, and may be repeated every to hours The higher dosage, and a dosing interval of every to hours, is suggested for those who take narcotics often (e.g., those with sickle cell disease or cancer) because they may have some tolerance to the drug If needed, a subsequent dose is reduced to 0.05 mg/kg if the patient is moderately sedated Due to a slower metabolism of this medication, young infants under the age of months should receive 0.05 mg/kg every to hours and they should be closely monitored When given intravenously, its effect is almost immediate, with the peak effect occurring in to 10 minutes Patients may experience pruritis due to histamine release and this is not necessarily an allergic reaction Morphine can cause hypotension because of both decreased peripheral vascular resistance and histamine release This is more often a concern in patients with severe injuries, who may be hypovolemic, or in those experiencing histamine release Certainly, the fluid status of an injured child requires careful attention from the ED staff, but pain control should not be withheld until after IV fluids have corrected volume depletion If the child is awake, alert, and screaming in pain, morphine can be given safely as long as the patient is monitored carefully If the patient has persistent hypotension, other agents such as fentanyl can be used to control pain