Question: how many milligrams of antihistamine can you take?
Answer: For oral dosage forms (capsules, tablets, or liquid): Adults—25 to 100 milligrams (mg) three or four times a day as needed. Children 6 years of age and older—12.5 to 25 mg every six hours as needed. Children 4 to 6 years of age—12.5 mg every six hours as needed.