What is the best medicine to prevent sinus infection?

Keep drainage active: Keep the drainage active and you can do that by 1 drink plenty of fluids to keep hydrated 2 use a central humidifier in your home, breathing dry air can hinder drainage 3use electrststic filters to your air conditioning vents 4 avoid chemicals or envoirenmental elements like pollen&cigarette smoke 5limit alcohol intake 6treat common cold properly 7 use nasal irrigation frequently 8 get flu shots.