For acute hives in a healthy adult, the maximum dosage of diphenhydramine is 300 mg per day orally, and for cetirizine, it is 10 mg per day orally.[1-2]
Diphenhydramine can be administered in doses of 25 to 50 mg orally 3 to 4 times daily, not exceeding 300 mg per day.[1]
Cetirizine is recommended at a dose of 10 mg once daily, either orally or intravenously.[2-3]
Loratadine is another option, with a maximum dosage of 10 mg per day orally.[4]
It is important to monitor for common side effects such as drowsiness, dry mouth, and dizziness, especially with diphenhydramine.[1]