You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Antihistaminic used in motion sickness is : and explain in detail?
Diphenhydramine and promethazine have maximum anti-cholinergic activity and maximum ability to cross the blood-brain barrier and are thus most effective in motion sickness.