Zyrtec and Benadryl are both brand names for drugs with generic names Cetirizine and Diphenhydramine, respectively. Both drugs are used to solve cases of allergies in patients. One of the major constituents of the two drugs is an antihistamine. That said, Benadryl is the older of the two drugs, and that is why it is usually regarded as the first- generation antihistamine, while the other drug can be regarded as a second-generation antihistamine.
Benadryl, being the older of the two, was first produced by Dr. George Rieveschl in 1946, while Zyrtec was first produced by Johnson & Johnson. Benadryl can be used to cure health cases like insomnia, allergies, motion sickness, cold, as well as the symptoms of allergies. In contrast, Zyrtec can be used to treat urticaria, angioedema, and hay fever.
The recommended dose of Benadryl for adults is 10mg, and 1/2 teaspoon for children between 6 months to 2 years old. The recommended Zyrtec for adults is 25-50 mg, and 12.4-25mg for children between 6-12 years old.