Q. A 32-year-old non-smoker male patient presents to the physician's clinic with a three-week history of a dry cough that worsens at night. He denies having fevers, chest pain, or shortness of breath. He mentions that he has been sneezing more frequently and that his eyes have been itchy. His vitals are normal, and the lung examination is clear without wheezing, crackles, or rhonchi. A chest x-ray shows no abnormalities, and his spirometry test indicates normal lung function. What is the most appropriate initial treatment for this patient?