12.5 mg of methotrexate per week is considered as low dose methotrexate. Non steroidal anti inflammatory drug like Aleve (piroxicam) can be taken without much interaction with low dose methotrexate. The major concern of NSAID use is that it may raise the methotrexate level in blood and cause toxicity. As you are on low dose methotrexate regimen, the chances are extremely less but I would advise caution and monitor for any adverse effect when using Aleve. I hope the above information helps you. Do consult your doctor before adding any new drugs in your regimen. Thanks for writing into healthcaremagic. Have a wonderful day.