THE IMPORTANCE OF MEASURING COTININE LEVELS TO IDENTIFY SMOKERS IN CLINICAL-TRIALS

First-time-in-humans studies of drugs (phase I) typically exclude unsu itable volunteers by testing for recreational drugs. However, voluntee rs are usually not screened for cotinine, a metabolite of nicotine, ev en though tobacco products may alter pharmacokinetic and pharmacodynam ic parameters and withdrawal from tobacco may cause additional adverse events. The accuracy of personal histories as means of excluding smok ers was examined prospectively in three phase I units in the northeast ern, midwestern, and southwestern United States. In studies intended f or nonsmokers, 45 of 282 purported nonsmokers screened before enrollme nt tested positive for cotinine. This suggests that personal histories are unreliable in determining tobacco use in clinical trials designat ed for nonsmokers.