Effect of Repeated Cocaine Administration on Detection Times in Oral Fluid and Urine

Abstract

Detection times reported for single-dose studies may not predict detection times following repeated cocaine dosing. Although repeated cocaine administration can result in drug accumulation and extended excretion time, there is a paucity of data from controlled dosing studies with repeated drug administration. We compared detection times for cocaine and benzoylecgonine (BZE) in oral fluid and BZE in urine following single and repeated cocaine dosing. Two groups of cocaine-experienced subjects participated in these studies. The single-dose group received cocaine by intravenous, intranasal, and smoked administration. The repeated dose group received daily escalating oral cocaine doses culminating in a total of 1,250-2,000 mg. Oral fluid and urine specimens following the last dosing were analyzed by gas chromatography-mass spectrometry. Detection times were determined as the time to the last positive specimen. The effect of repeated dosing was to extend oral fluid detection times for cocaine approximately fourfold and BZE detection times sevenfold, whereas urine BZE detection times were extended twofold. Because cocaine abusers frequently self-administer higher and repeated doses, we conclude that the short detection times observed in single-dose studies underestimate the utility of oral fluid for detection of cocaine abuse in realistic settings.

Times of Detection of Drugs of Abuse in Saliva: Study of Arrested Population

“…Only a few investigators have evaluated the pharmacokinetics of orally administered cocaine and even less has been published about the pharmacokinetics of chronic cocaine administration [6,7,8]. These results do not match with previous data known about the rapid decrease of cocaine and acceptance that drugs in saliva follows the same metabolic course that in blood.…”

“…These authors indicate an average life of elimination of cocaine in saliva between 21.6-110.4 h. In chronic users even it can reach 10 days with a LOD 0, 5 ng/ml. Other authors agree with this statement [7]. It remains unclear how repeated dosing alters or prolongs detection times.…”

The New Substance Abuse and Mental Health Services Administration Oral Fluid Cutoffs for Cocaine and Heroin-Related Analytes Applied to an Addiction Medicine Setting: Important, Unanticipated Findings with LC-MS/MS

“…A real practice study of 16 pregnant women on methadone therapy for opiate abuse involving 403 OF samples (13 ), with LOQs of 1 g/L, found COC 111 times compared to 98 times for BZE. Additional reports (10,11 ) showed that repeated dosing of COC in 6 male individuals led to prolonged detection times for COC and BZE in both OF and urine compared with detection times from single-dose experiments. Importantly, OF COC and BZE were shown to have different elimination profiles (10,11 ), COC having a rapid initial elimination phase followed by a much slower one, and OF BZE with only a single, intermediate one.…”

“…Additional reports (10,11 ) showed that repeated dosing of COC in 6 male individuals led to prolonged detection times for COC and BZE in both OF and urine compared with detection times from single-dose experiments. Importantly, OF COC and BZE were shown to have different elimination profiles (10,11 ), COC having a rapid initial elimination phase followed by a much slower one, and OF BZE with only a single, intermediate one. These results were attributed to storage of COC in adipose tissue, resulting in prolonged release of COC during abstinence.…”

“…Several reviews (1)(2)(3) and other documents (5,6 ) compile the numerous studies that have investigated cocaine, heroin, and their metabolites in OF. Much of the OF literature consists of excellent, controlled-administration drug disposition studies (7)(8)(9)(10)(11). There are reports showing OF cocaine and/or heroin metabolite concentrations in moderate-to-large realistic clinical settings (12)(13)(14)(15)(16)(17)(18).…”