Disclaimer: This Buzzle article is for informative purposes only, and should not be used as a replacement for expert medical advice. In order to kill or prevent the growth of bacteria responsible for a sinus infection, many doctors often recommend taking antibiotics. Amoxicillin, being an antibiotic, is usually given orally or intravenously. Deciding Factors for Giving the Antibiotic How well the antibiotic works will depend on the type of infection you have―actue or chronic. While your healthcare provider will decide whether or not amoxicillin should be given, you need to be aware of certain important points. Acute Sinusitis Depending on your current physical health, your doctor will prescribe you the antibiotics for a specific number of days. However, if your condition doesn't improve in 3 to 5 days, perhaps a different antibiotic may be prescribed. Including the antibiotic, you may also be given certain decongestants that will help improve the sinus drainage. Chronic Sinusitis On the other hand, if you have been suffering from sinusitis, off and on, for a long period of time, the exact antibiotics prescribed by your doctor will depend on your current physical health, whether or not you've been given amoxicillin before, if it was helpful, and how severe the infection is at that moment. Dosage Although your doctor will recommend a dosage for you, mostly he/she will ask you to take the 500 mg of amoxicillin every 8 or 12 hours by mouth with or without food. You need to take the full prescribed amount instructed by your doctor, or until the symptoms no longer exist in a few days. However, if you stopping taking the medication too soon, chances are the infection will return. The antibiotic can be taken in pill or liquid form as well. When taking it in a pill form, remember that it should not be chewed or crushed. If you have been given the liquid suspension form, you should make sure that you measure the prescribed dosage with the medicine dispenser, and not by using a spoon. Side Effects As all medication have certain side effects, you should be aware of the ones related to taking this antibiotics as well. From mild to severe, the side effects may include: If you can't breathe on your own and/or your face, lips, tongue, or throat are swollen, you need to call 911 immediately. On the other hand, if any of the other side effects appear, call your doctor for immediate medical help.