"i have a severe back condition which has resulted in chronic lower back pain for more than 25 years. i was using oxycodone (oxycontin) and other pain related drugs until i developed a very severe allergic reaction. i started on duragesic 50mcg patch which i have tolerated with only the very minor side effect of mild constipation about once every 2 - 3 months. i have moved to the duragesic 100mcg patch for the past 4 %u2013 5 years, this medicine is a true wonder. i am able to adjust my dosage from between 50 to 100mcg as required, and the most important thing is that i can lead a normal life mostly pain free. the patch lasts between 48 to 72 hours dependent upon my activity, if i sweat the patch only lasts 48 hours."