Question: diphenhydramine hydrochloride how much to take?
Answer: For self medication, 25 to 50 mg PO every 4 to 6 hours as needed, not to exceed 300 mg in 24 hours. For self-medication, 12.5 to 25 mg PO every 4 to 6 hours, not to exceed 150 mg in 24 hours. NOTE: The FDA recommends that OTC cough and cold products not be used for sedation in children of any age.