Question: how many antihistamines can you take in one day?
Answer: For oral dosage forms (syrup and tablets): Adults—5 to 10 milligrams (mg) once a day. Children 6 years of age and older—5 to 10 mg once a day. Children 4 to 6 years of age—2.5 mg once a day, up to a maximum of 5 mg once a day or 2.5 mg twice a day.