During the past two decades our understanding of mechanisms involved in pain transmission or modulation has progressed. Such progress is habitually followed by novel analgesic treatments introduced into the clinic. The initial euphoria created by the introduction of new treatments often recedes as the new treatment is tested in the clinical environment.

Clinical trials are the definitive umpire of the usefulness or otherwise of analgesic treatments developed following basic science discoveries. This fact is quite often overlooked in the scientific community, where research discoveries almost instantly attain religious status, with clinical research receiving less status and priority. However, many health providers now realise that analgesic treatments require justification by documented clinical effectiveness. Consequently increasing efforts are attempting to improve the quality of analgesic trials. This chapter addresses some of the major practical problems that can determine the outcome of a clinical analgesic trial.

Types of clinical analgesic trials

Clinical trials are basically done for three reasons:

1. The pharmaceutical industry conducts small- and large-scale trials as part of their investigational new drug (IND) programmes (see Table 30.1). IND programmes are based on commercial contracts between the industry and clinics. Large-scale trials are usually undertaken by contractual research organisations (CROs) consisting of collaborating clinics.

2. Clinical trials are routinely conducted at academic institutions as part of academic training programmes.

3. […]