If you have been taking Naproxen for 4 days and are not seeing any improvement in your knee inflammation and pain, it may be a good idea to consult with a healthcare professional again. Depending on the severity of the pain, it is important to follow their advice on medication dosage and frequency, as well as any additional treatment recommendations they may provide. Persistent or worsening pain and inflammation after a certain period of time may require further evaluation and possibly different treatment options.