Yes, it is, and I hope it worked.. however, Methadone has to build up in your system before it has an effect. It's meant to be a long term, consistent drug, and should be taken regularly as prescribed. It must be taken consistently, and by taking Oxy you are slightly upsetting the balance that methadone puts into your system. It's only short term and temporary, and is not a problem at all with occasional pain, just be careful with the amount and frequency. If you are experiencing a lot of pain and find yourself needing it a lot, talk to your doctor for a possible adjustment of your methadone treatment