You would need to know the cause of the cough before taking any medications. Cough can be caused by a variety of mechanisms, and the treatment may vary depending on the mechanism. I don t see any connection between the herpes infection and this cough. Cough can result from lung disease, including damage from smoking, inflammatory conditions, pneumonia, bronchitis, asthma. It can also be related to post nasal drainage from sinus problems or allergies, from acid reflux from the stomach, irritation of the vocal cords/throat, or many other possibilities. It would be best that he see a doctor and get evaluated for these conditions so that a more specific treatment can be prescribed. Hope this helps.