3. Dose-response

Dose-response data is very important. In addition to formal dose-response studies, the sponsor of a clinical trial should look at the entire database of data for possible dose-response information (for example results from studies with fixed doses, blood concentration-response relationship from the variable concentrations attained in a fixed dose trial, etc.).

Dose-response studies are typically randomised parallel group studies which look at three or more dosage levels, one of which may be zero (placebo). It may also be useful to include one or more doses of an existing medicine as a control.

The information gained from dose-response studies:

  • Identify a reasonable starting (minimum effective) dose, ideally with specific adjustments.
  • Identify response-guided stepwise dose adjustment (titration) , and the intervals at which they should be taken.
  • Identify a dose, or a response (desirable or undesirable), beyond which titration should not ordinarily be attempted because of lack of further benefit or an unacceptable increase in undesirable effect.
  • Identify optimal dose