5 1/2 yr old takes children's claritin every am but is still plagued with allergic cough - worse at night. ok to dose with benadryl (diphenhydramine) in the pm?

Yes: Be sure to speak with your pediatrician or allergy-immunology specialist regarding an appropriate dose for your child's weight. Often times severe allergies are treated with antihistamines alone like claritin/nondrowsy and Benadryl (diphenhydramine) together. Other options are available if Benadryl (diphenhydramine) doesn't work. Sedation and dry mouth are common side effects. Consider saline spray and environmental changes.