You can take two medications together only if they have different working mechanisms and actions. Fortunately, oxycodone and indomethiciane are so. One is a pain killer (oxycodone) and the other is an anti-inflammatory medicine (indomethiciane). But before taking them, you should be aware of the side effects of each medicine. Oxycodone is a medicine which belongs to the opiate group of drugs and so is highly addictive. It posses severe withdrawal symptoms also, including fever, nausea, vomiting, diarrhea, insomnia, muscle pains and chills when you suddenly stop this medicine. Intense craving is seen in patients who try to stop these using lower doses of this medication. Indomethiciane on the other hand causes gastro-intestinal adverse effects as side effects. Indigestion, bleeding, abdominal pains, flatulence and kidney related issues. These problems can occur without showing any warning symptoms. So, consult with your doctor for getting suggested with the apt medication for you.