Irrational drug design

Some would argue that drug discovery through screening provides the irrational counterpart to rational drug design. This remark is unjustifiably harsh and is somewhat... 

Although combinatorial chemistry may be applied to a variety of areas of chemistry, to date, the majority of practical applications have been dedicated to drug discovery projects. Combinatorial chemistry is undoubtedly an efficient method for the preparation of compounds in a variety of library sizes. This approach, however, also makes combinatorial chemistry an efficient method for the production of useless or inactive compounds. For this reason, the technique has sometimes been referred to as an irrational design process, in contrast to the accepted rational drug design process traditionally practiced by medicinal chemists. 

Focused drug use evaluation (drug utilization review) can be done to identify problems concerning the use of specific medicines or the treatment of specific diseases, particularly in hospitals. The qualitative methods employed in social science (e.g. focus group discussion, in-depth interviews, structured observation and structured questionnaires), can be used to investigate the motives underlying irrational use. All data collected should be used to design interventions and to measure the impact of those interventions on medicine use. 

Screening combinatorial libraries should not imply a random or irrational approach to drug discovery. Far from obviating the use of computers, the increased complexity of combinatorial drug discovery makes their use ever more essential. Although the number of compounds that could be made is enormous, a well-planned experimental design selects a reasonable number of compounds that sample the range of accessible properties. 

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