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 Your medical student patient suffers from troublesome allergic rhinitis due to pollen, and you want to prescribe a drug for her that is least likely to cause sedation. Your best choice would be and explain in detail?
The usual choice for pollen-induced allergies would be an H1 antagonist. Of the two listed, loratadine would be the best choice in this case because it does not cross the blood-brain barrier and is nonsedating; hydroxyzine is an effective CNS depressant used for preoperative sedation. Cromolyn (not listed) can also be used in allergic rhinitis and is also non-sedating. Betamethasone, a potent anti-inflammatory steroid, is less effective than antihistamines in this situation and would cause more serious side effects. Metoclopramide is a DA receptor antagonist and prokinetic used as an antiemetic and in GERD. Cimetidine is the prototype H2 antagonist used in GI ulcers.