Enzymatic assay for urine lactose in the assessment of recent intravenous abuse of buprenorphine

Abstract

Laboratory methods for differentiating intravenous substance abuse from medical oral or sublingual use are lacking. The disaccharides lactose and sucrose are common excipients in both medical preparations and illicit drugs. If substances are abused intravenously, the disaccharides are excreted unchanged in urine. This study evaluated whether urine lactose indicates recent intravenous abuse of substances with special reference to buprenorphine (BPN). Samples were attained from 21 patients in assessment for opioid maintenance treatment (OMT) and from 29 patients already enrolled in OMT. Patients were divided in two groups. Group 1 patients reported intravenous abuse of BPN within 48 hours and Group 2 more than 48 hours since the last injection. The urine samples were assayed for lactose using an enzymatic method. To verify intravenous abuse, examination of needle marks and mass spectrometric analysis of abused substances was performed. Urine lactose concentration was significantly higher in Group 1 (86 mg/L) than in Group 2 (24 mg/L). All samples with lactose concentration more than 140 mg/L were given by the Group 1 patients, who all had recent injection marks. A significant inverse correlation was found between the time from last injection and the urine lactose concentration within the 48‐hour post‐injection period. Elevated lactose concentrations in urine could indicate intravenous abuse of substances containing lactose. The co‐occurrence of higher than 140 mg/L of lactose in urine by means of enzymatic assay verified by fresh puncture sites is a potential indicator of recent intravenous abuse of BPN.

Determination of buprenorphine, norbuprenorphine, naloxone, and their glucuronides in urine by liquid chromatography–tandem mass spectrometry

“…Altogether 72 patient urine samples were analysed using the developed LC‐MS/MS method. This is a substudy of a previous clinical study 58 for which the samples had been collected from BUP‐dependent patients either being assessed for need for OAT or already enrolled in OAT at the outpatient clinic for opioid‐dependent patients of Helsinki University Central Hospital (HUCH). The study was approved by the HUCH Ethics Committee for Gynaecology and Obstetrics, Paediatrics, and Psychiatry (HUS/1518/2016).…”

“…Peaks in period 2: norbuprenorphine-glucuronide (NBUP-G), norbuprenorphine (NBUP), buprenorphine-glucuronide (BUP-G), and buprenorphine (BUP) [Colour figure can be viewed at wileyonlinelibrary.com] Patient urine sample collection for LC-MS/ MS analysisAltogether 72 patient urine samples were analysed using the developed LC-MS/MS method. This is a substudy of a previous clinical study58 for which the samples had been collected from BUPdependent patients either being assessed for need for OAT or already enrolled in OAT at the outpatient clinic for opioid-dependent patients of Helsinki University Central Hospital (HUCH). The study was approved by the HUCH Ethics Committee for Gynaecology and Obstetrics, Paediatrics, and Psychiatry (HUS/1518/2016).…”