You should, however, use over-the-counter or prescription decongestant nose drops and sprays for only few days. If you use these medicines for longer periods, they can lead to even more congestion and swelling of your nasal passages.

If bacteria cause your sinusitis, antibiotics used along with a nasal or oral decongestant will usually help. Your health care provider can prescribe an antibiotic that fights the type of bacteria most commonly associated with sinusitis.

Many cases of acute sinusitis will end without antibiotics. If you have allergic disease along with sinusitis, however, you may need medicine to relieve your allergy symptoms. If you already have asthma and then get sinusitis, you may experience worsening of your asthma and should be in close touch with your health care provider.
http://www.niaid.nih.gov/factsheets/sinusitis.htm