Abstract
It has been reported that previous participation by subjects in Phase I studies may influence the incidence of adverse events; however, the relationship between them remains to be determined. Therefore, we compared the incidence of adverse events in first time drug trial subjects receiving active drug or placebo treatment at our institute with subjects who had been previously enrolled in a Phase I study. We retrospectively reviewed the adverse events reported in 26 single-dose studies (PK.) involving 939 healthy male volunteers (active drug 667, placebo 272) . The overall incidence of adverse events in subjects receiving an active drug was 16.0% (13.6% in the subjects who participated only once, 18.0% in those who participated more than once, P=0.194) whilst the frequency of adverse events in subjects receiving a placebo was 10.7% (14.4% in subjects who participated only once, 8.1% in those who participated more than once, P= 0.137) . The incidence of adverse events in the subjects who participated once and those who participated more than once was not significantly different with either active drug or placebo treatment. The number of times a subjects had participated in a drug study did not affect the incidence of adverse events in single-dose Phase I studies at our institute.
