agefactors anesthesia anti-infectiveagents breastfeeding chemotherapy child clinicaltrials clinicaltrialsastopic design drug-relatedsideeffectsandadversereactions drugeffects drugevaluation drugs drugtherapy effectofchemicalson effectofdrugson ethics human infant infants methods milk neoplasms newborninfants pediatricanesthesia pediatrictoxicology pharmacology qz267r7451985 risk standards testing tumorsinchildren wo440 ws125h164d2001