If you are experiencing a persistent dry cough, it might be helpful to consider if you have a runny or blocked nose as well. Sometimes post-nasal drip can cause a cough as the mucus drips down the throat. In this case, an antihistamine like Claritin or Aerius could be worth trying to help alleviate the symptoms. It is best to consult with a pharmacist to determine the right medication for your specific situation, taking into account any allergies, current medications, or pregnancy or breastfeeding status.