Phase I and Phase II portions of the study:
- 18 years of age or older
- Chronic pain with average 24 hour intensity rated at least 3 on a verbal numerical
scale from 0-10 during the 24 hours prior to study entry.
- Give informed consent to participate in this study.
- Karnofsky Performance Score (KPS) >= to 80
- Negative urine pregnancy test, verified by the study nurse, at study entry (for women
of child-bearing potential). Patients must also use a medically approved
contraceptive method during the study period.
Phase I only:
- Responsible companion living with patient during study.
Phase II only:
- Group 1 -- Patients must be taking chronic opioid therapy (long acting morphine, long
acting oxycodone, transdermal fentanyl) at a stable dose for a minimum of four days.
The dose of as needed short acting opioid does not need to be stable.
- Group 2 -- Patients must not be receiving opioids and must have cancer related
neuropathic pain secondary to post-chemotherapy peripheral neuropathy, post-radiation
and/or post surgical plexopathy, radiculopathy or neuropathy, or post- herpetic
Phase I and Phase II:
- Known hypersensitivity to methadone
- Patient taking methadone or with a history of methadone treatment within one month of
- Patient that requires changes in the dose of one of the following medications within
2 weeks of study enrollment:
- FOS amprenavir,
- St. John's Wort,
- Hepatic function tests (SGOT, alkaline phosphatase, bilirubin) greater than 2 times
the upper limit of normal or creatinine greater than 1.4 within 30 days of study
- Neurologic or psychiatric disease sufficient, in the investigator's opinion, to
compromise data collection.
- Women who are pregnant or nursing.
- Women of childbearing potential who do not agree to use a medically recognized method
of contraception during the study period.