What Does Effective Dose 50 (ED50) Mean?
Effective dose 50 (ED50) is a pharmacological term for the dose or amount of drug that produces a therapeutic response or desired effect in 50% of the subjects taking it. ED50 is dependent upon the patient and can vary according to their age and health, although the dose administered by a physician should fall into the drug's predetermined therapeutic window.
It is also known as a median dose.
Safeopedia Explains Effective Dose 50 (ED50)
The ED50 is determined during new drug clinical trials and in studies of existing drugs when adverse reactions are discovered in drug combinations.
There are 4 phases of clinical trials.
Phase 1: Initial safety trials on a new medicine, attempting to establish the dose range tolerated by volunteers.
Phase 2a: Pilot clinical trials to evaluate efficacy (and safety) in selected populations of patients with the disease or condition to be treated, diagnosed, or prevented.
Phase 2b: Usually the most rigorous demonstration of a medicine's efficacy. Sometimes referred to as pivotal trials, since they make or break the drug’s effectiveness. The ED50 is calculated from data obtained during the trial. The drug will not continue in clinical trials if it doesn’t meet the effectiveness goal reflected from data or the calculated ED50
Phase 3a: Trials conducted after efficacy of the medicine is demonstrated. Phase 3a clinical trials generate additional data on both safety and efficacy. The trials are conducted in relatively large numbers of patients in both controlled and uncontrolled trials. Clinical trials are also conducted in special groups of patients.
Phase 4: The drug safety and efficacy may be evaluated for a significant period of time after it is on the market. ED50 may be revised based on Phase 4 data. Different formulations, dosages, durations of treatment, medicine interactions, and other medicine comparisons may be evaluated. New age groups, races, and patient demographics can be studied.