Morphine has pharmacokinetic differences in young individuals, that may predispose them to develop respiratory depression. So this drug should be used with caution in infants less than 6 months of age who are not ventilated. Drugs used in the induction of anesthesia in children are a mixture of oxygen and nitrous oxide. Other drugs which are useful are sevoflurane or halothane. Sevoflurane is considered to be the agent of choice for inhalational induction rather than halothane, because sevoflurane has a wider therapeutic safety window in terms of cardiovascular depression and has no unpleasant smell. Ref: Synopsis of Pediatric Emergency Medicine By Gary Robe Fleisher, 4th Edition, Page 34 ; Textbook of Anesthesia for Postgraduates By T. K. Agasti, Page 799