No, you shouldn’t take Nyquil with Hydromet Syrup. The homatropine in hydromet and doxylamine are very similar. They can cause excess sedation, dry mouth, and possibly palpitations if taken together. Your nyquil contains dextromethorophan, a cough suppressant, and tylenol/acetaminophen for pain. They hydrocodone will tackle cough and pain. ! Any comments?