[Drug Excipients. Necessary, but not Harmless]

Medicines are made up of one or more active ingredients and excipients. Active ingredients have pharmacological action and cause adverse reactions to medications, but what about excipients? They are necessary to achieve the appropriate properties of the medication, but they are not always harmless and can also cause adverse reactions.In order to provide community pharmacists with quick reference material during dispensing services, thus ensuring safe use of medicines, a bibliographic review of the available literature has been carried out, focusing on the identification of possible adverse reactions associated with excipients present in medicines and vaccines in both the pediatric and adult populations. A series of reference tables have been developed indicating potentially dangerous excipients, the adverse reactions they make produce, and the precautions to be taken into account in certain pathologies or if they are intended for the pediatric population.