The recommended dosage of Telfast 180 mg for adults and children over 12 years old is one tablet once daily. Taking 2 tablets of Telfast 180 mg per day is not recommended. The usual dose is one tablet daily for relief of hayfever symptoms or hives. Taking more than the recommended dose may increase the risk of side effects such as dizziness, drowsiness, fatigue, and dry mouth. If in doubt or if symptoms persist, it is best to consult a doctor or pharmacist before taking more than the prescribed dose.