ASSESSMENT OF COCAINE USE WITH QUANTITATIVE URINALYSIS AND ESTIMATIONOF NEW USES

Qualitative urinalysis methods of monitoring cocaine use may over-dete ct frequency of use, possibly decreasing the ability of clinical trial s to detect effective treatments. Quantitative urinalysis and newly de veloped criteria for identifying new cocaine use were evaluated as alt ernative measures of cocaine use. Urine specimens collected in a cocai ne dosing study in nan-treatment-seeking subjects (n=5) and a cocaine treatment trial (n=37) were analyzed for the cocaine metabolite, benzo ylecgonine, with qualitative and quantitative methods. Pharmacokinetic criteria ('New Use' rules) were applied to quantitative data to ident ify occasions of new cocaine use. Results were compared to known cocai ne administrations in the laboratory study and to self-reported drug u se and qualitative urinalysis for subjects in the clinical trial. New Use criteria correctly identified cocaine administrations in the cocai ne dosing study in all but a small number of specimens. In the clinica l trial, quantitative urinalysis and estimated New Uses provided more information about patterns and frequency of use than qualitative urina lysis in the different treatment conditions in the clinical trial. Int erpretation of quantitative urinalysis with New Use rules appears to b e a useful method for monitoring treatment outcome and may be more acc urate than traditional qualitative urinalysis in estimating frequency of cocaine use.