Drug prescribing and drug administration

Abstract Safe prescribing during pregnancy and lactation requires an understanding not only of the effects of a drug on the mother but also on the fetus or infant. Many mothers are prescribed at least one medicine with the potential for harmful effects on either the fetus or infant. Few drugs are deemed safe and effective during these periods and most medications in pregnancy are used ‘off label’. Neonates, too, are ‘therapeutic orphans’—most drugs used in the neonatal intensive care unit (NICU) are not approved for use in this population of patients by any regulatory authority and are, therefore, used ‘off label’. As such there is greater onus on the prescriber to make sure that they understand the consequences of their prescription. This first part covers important aspects of prescribing, medicines storage, and administration. It also explains how medicines safe at other ages cause toxicity, not just from the drug itself but also from the excipients that are sometimes required.