Designing drug efficacy trials in the treatment of cocaine abuse.

A variety of pharmacological approaches have been introduced to reduce cocaine craving and use. Most of these have been tested in open-label, noncontrolled trials; there is a need for more definitive placebo-controlled investigations. An overview of research design issues involved in the planning of such studies is presented. Discussion of the potential aims of drug trials and the basic principles of methodology and data analysis is intended to facilitate the undertaking of such studies by clinicians in the field of substance abuse as well as by clinical researchers not currently working in substance abuse.