Methods of Rotation From Another Strong Opioid to Methadone for the Management of Cancer Pain: A Systematic Review of the Available Evidence

Evidence identified was mainly from uncontrolled observational studies, making causality difficult to establish. Studies were heterogeneous in methodology and outcome measures. There was a trend toward excess AEs using the RC method, in comparison to the AL and 3DS methods. The methodological quality of the AL studies was low. A direct comparison of AL and 3DS methods would be informative.