Infants and young children treated with heart drugs get the wrong dose or end up on the wrong end of medication errors more often than older children, according to new research.

The researchers found the highest number of errors among infants under the age of 1. However, children of all ages are vulnerable to such mistakes because health-care providers can manually miscalculate weight-sensitive doses and can misinterpret safe age ranges of adult drugs used off-label in children.

The report and the warnings were drawn from a study analyzing 821 medication errors submitted to a national voluntary error-reporting database. Errors occurred every step of the process of calculating dosages, prescribing, dispensing and giving drugs.