Monitoring Addiction to Pregabalin in Northern Algeria by Using Hair Testing

Pregabalin (PGB) is a novel gamma-aminobutyric acid analog that has been recently approved for the treatment of partial-onset seizures, neuropathic pain, and fibromyalgia. Although PGB presents a low potential for abuse in comparison to other scheduled drugs, the literature reports its potential misuse, especially among individuals with former or current drug addiction. The present study aimed to develop and validate a novel method for the determination of PGB in hair to perform a retrospective observational study on the misuse of this drug in a population of addicted subjects from Northern Algeria. Hair and urine samples were collected from patients (n = 79) with a history of illicit drug use, monitored by the Intermediate Addiction Care Center of Constantine (Algeria). None of the patients had a medical prescription for PGB. Samples had also been tested for the presence of other drugs of abuse with routine LC-MS/MS methods. Hair samples (∼25 mg) were analyzed for PGB after sonication for 2 h in acetonitrile. The organic phase was dried and reconstituted in 100 µL mobile phase and analyzed by LC-MS/MS. The method was fully validated with LOD and LOQ results of 10 and 20 pg/mg, respectively. The linearity was verified in the 20-1000 pg/mg range. PGB was found in the hair samples of 51/79 subjects, with concentrations ranging from traces to 380 pg/mg. The study revealed that about 65% of the subjects used PGB in the absence of any medical prescription, indicating the potential misuse of this drug.