Time to Break-up with Benadryl?

Diphenhydramine (trade name Benadryl) is an older, first generation antihistamine which has significant and common side effects including sedation, cognitive impairment, poor sleep quality, dry mouth, dizziness, and low blood pressure. Even at appropriate doses, diphenhydramine can cause a paradoxical reaction in kids, making them hyperactive and agitated (think toddler after 3 shots of espresso!). In very rare cases, these drugs have also resulted in death from intentional or unintentional overdoses. Because of these safety concerns, in 2009 Health Canada banned the use of first generation antihistamines in cough and cold medications for children under 6. 

Newer, less-sedating antihistamines like cetirizine (Reactine), fexofenadine (Allegra), and loratidine (Claritin) have been shown to be safer and more effective than benadryl in high quality trials. 

The Canadian Society of Allergy Clinical Immunology (CSACI) recommends that newer generation antihistamines should be preferred over first-generation antihistamines for the treatment of hay fever, pet allergies, and hives. 

All of these newer antihistamines are available over-the-counter in paediatric formulations and in generic form. 

References: 

https://doi.org/10.1186/s13223-019-0375-9