Concentrations of cocaine and two of its metabolites (ecgonine methyl ester and benzoylecgonine) also increased in the weekly samples (Figure , Table ). Anhydroecgonine, a metabolite specific for crack cocaine , decreased in the weekly samples, suggesting the possibility of a shift in local cocaine use patterns (Figure ). We saw no trends for methamphetamine, though the party drug TFMPP decreased during the study period (Table , Table ). Cannabis related compounds did not show a consistent trend.