Parallel consumption of pregabalin in opioid maintenance treatment detected by multi-target screening in oral fluid

Introduction: Despite sufficient doses of opioids under substitution, the co-occurring abuse of other substances is a clinically relevant and potentially life threatening issue. In clinical routine only standard substances such as opiates, cocaine, etc. are tested, while other substances remain undetected. In Apr 2013, we used a multi-target screening test to analyse oral fluid samples of substituted patients in order to identify 55 single substances, including pregabalin known to be related to deaths in patients with opioid dependence. Method: Oral fluid samples were collected using the Greiner-Bio-One SCS ph 4.2 device according to the manufacturer. Routine pregabalin screening in oral fluid was performed by an UPLC-MS/MS multi- target method. From a total of 389 tested patients we ran an extensive test with 134 individuals for 4 weeks. Result: 90 of 389 patients (= 23%) were tested positive for pregabalin. 27 (61%) individuals out of 44 with positive pregabalin samples were identified continuously using pregabalin. Compared to pregabalin the occurrence of benzodiazepines in oral fluids was significantly lower (20%). Discussion: The parallel consumption of pregabalin is a highly important issue for opioid patients under substitution therapy. However, currently available urine drug testing is insufficient regarding this substance. According to our data improved standard diagnostic procedures should be used to increase and maintain the safety of opioid substitution therapy.