Phase IV research by pharmaceutical companies

The paper reviews the objectives and methods of phase IV studies performed by a pharmaceutical company with psychoactive drugs. After the introduction of a new drug additional information is needed especially regarding the safety of the drug. The term Post-Marketing Surveillance (PMS) covers all the methods used to collect this tolerability data. They include spontaneous monitoring by physicians, monitored release and related techniques, intensive monitoring typically in a hospital setting, case-control studies and cohort studies. Typical examples of new patient populations which are not usually studied extensively during the premarketing phases of drug development and which therefore need to be studied in more detail in phase IV are children and the elderly. In both of these groups certain special aspects have to be taken into consideration when planning and conducting clinical trials. Extension of the drug to new indications often starts spontaneously as observations of alert clinicians which then lead to systematic controlled trials. The methods used in the monitoring of physicians' prescription habits include the use of available commercial statistics, ad hoc physician surveys and the collecting of information through the medical representatives of the company.