1.	Phase III Compazine vs Methadone vs Tetrahydrocannabinol vs Placebo in Patients Receiving ADR for Malignant Neoplasms Phase: Phase III, Phase II Type: Supportive care Status: Completed Age: no age specified Sponsor: Protocol IDs: MAYO-818304, NCCTG-818304, NCI-W82-1092, W82-1092
2.	Switching From Morphine to Methadone. A Clinical, Pharmacological and Pharmacogenetic Study Phase: Phase III Type: Supportive care Status: Completed Age: 18 and over Sponsor: Other Protocol IDs: OPI 03/008, NCT00184496
3.	Morphine Versus Methadone As First Line Strong Opioid for Cancer Pain Phase: Phase III Type: Supportive care Status: Closed Age: 16 and over Sponsor: NCI, Other Protocol IDs: 2007-0477, NCT00634010
4.	Study of D-Methadone in Patients With Chronic Pain Phase: Phase II, Phase I Type: Supportive care Status: Completed Age: 18 and over Sponsor: Other Protocol IDs: 01-017, NCT00588640
5.	Sublingual Methadone for the Management of Cancer-Related Breakthrough Pain in Outpatients Phase: Phase II Type: Supportive care Status: Temporarily closed Age: 18 and over Sponsor: Other Protocol IDs: 20144, 22206, NCT00351715
6.	Role of Methadone As Co-Opioid Analgesic Phase: Phase II Type: Supportive care Status: Closed Age: 18 and over Sponsor: Other Protocol IDs: 2006-0641, NCT00558870
7.	Sublingual Methadone for the Management of Cancer Breakthrough Pain Phase: Phase I Type: Supportive care Status: Completed Age: 18 and over Sponsor: Other Protocol IDs: 17208, Calgary Health Region, NCT00125294
8.	Randomized Study of Opioid Rotation to Methadone Versus Opioid Rotation to Sustained-Release Morphine or Oxycodone in Patients Receiving Opioid Analgesics for Cancer Pain Phase: No phase specified Type: Supportive care Status: Completed Age: 18 and over Sponsor: NCI Protocol IDs: MDA-2007-0791, 2007-0791, MDA-05-08-04, 8208, NCT00726830