A couple questions... You say 150mg... I assume this is in multiple doses each day? (so, 3 doses, 50mg dose?) The mg per dose makes a big difference in any conversion rate. The problem with switching, is any medication you switch to isn't going to provide the same benefits as methadone. Methadone works on different receptors than some pain medications, so the specific pain "locations" make a big difference. I assume you've seen a pain specialist for your issues? Have you discussed switching with your doctor? That said...in answering your question... You can do a conversion, to see what the likely dose of another medication would be, but there is a calculation that doctors use, including the "incomplete cross tolerance" that is usually 25-75%, depending on your age, and a number of other factors. I used a 50% incomplete cross tolerance, just to get a number, and found that for morphine, you're dose would be 140.62mg-421.88mg/daily. There is a great discrepancy in the amounts, just depending on these other factors. There is an online calculator you can use, where you input the mg/daily of methadone, the % cross tolerance, and the medication to be switched to, and it will give you numbers. http://www.globalrph.com/narcotic.cgi I do really suggest you talk to your doctor, but hopefully this info will help. Here is the information about the incomplete cross tolerance: Incomplete cross-tolerance relates to tolerance to a currently administered opiate that does not extend completely to other opioids. This will tend to lower the required dose of the second opioid. This incomplete cross-tolerance exists between all of the opioids and the estimated difference between any two opiates could vary widely. This points out the inherent dangers of using an equianalgesic table and the importance of viewing the tabulated data as approximations. Many experts recommend - depending on age and prior side effects - reducing the dose of the new opiate by 33 to 50 precent to account for this incomplete cross-tolerance. (Example: a patient is receiving 200mg of oral morphine daily (chronic dosing), however, because of side effects a switch is made to oral hydromorphone 25 - 35mg daily - (this represents a 33 to 50 percent reduction in dose compared to the calculated 50mg conversion dose produced via the equianalgesic calculator). This new regimen can then be re-titrated to patient response. In all cases, repeated comprehensive assessments of pain are necessary in order to successfully control the pain while minimizing side-effects