why would anti-inflammatory drugs be prescribed for pleurisy?

Once your doctor identifies the source of inflammation or infection, he or she will be able to determine the correct course of treatment. Getting adequate rest to assist your body with the healing process is an important part of getting well. In addition, lying on your painful side may provide just enough pressure to make the pain go away.

Other methods of treatment include:

antibiotics (in the case of bacterial infection)
over-the-counter medicines, including aspirin, ibuprofen or other nonsteroidal anti-inflammatory drugs
prescription pain and cough medication (sometimes codeine-based cough syrups)
using medications to break up any blood clots or large collections of pus and mucus, which is then drained out via a tube