Dose-response relationship: relevance for clinical use

Dose-finding studies are performed routinely in patients and - if appropria te surrogate models exist - also in healthy volunteers. Such studies aim at establishing the optimal dose range for further clinical studies on the ef ficacy and the risk-benefit ratio of a new drug. The dose-response relationship of a drug is most often described by a sigmo idal curve. Its parameters include the mean effective dose, the maximal eff ect and the steepness. Interpretation of such curves should be done in the context of the intended clinical indications of the drug. The risk-benefit ratio of a drug can be assessed by overlapping the dose-re sponse curve of wanted and unwanted clinical effects, again, any overlappin g (which can be described e.g. by the therapeutic index) should be seen in the context of the indication and available therapeutic alternatives.