Methamphetamine as the most common concomitant substance used with pregabalin misuse

Area of Science:

• Forensic Toxicology
• Clinical Chemistry
• Addiction Medicine

Background:

• Non-medical use of pregabalin (PGB) presents significant public health and legal challenges.
• Increased PGB administration in judicial, treatment, and general populations often occurs without prescription and at high doses.
• Routine analysis for PGB is crucial for differentiating medical use from abuse.

Purpose of the Study:

• To analyze PGB in urine samples from forensic and clinical cases using LC-MS/MS.
• To determine the prevalence of PGB and identify concomitant substances in cases of suspected abuse.
• To evaluate the sociodemographic and clinical characteristics of PGB-positive individuals.

Main Methods:

• Urine samples from 640 forensic (probation system) and 371 clinical cases were analyzed between December 2022 and April 2023.
• Initial screening by immunoassay was followed by LC-MS/MS for simultaneous detection of multiple drugs, including PGB.
• PGB was incorporated into routine screening in December 2022.

Main Results:

• PGB was detected in 12.3% of probation cases and 13.2% of clinical cases, predominantly in young males (mean age 26.55 ± 7.52).
• Amphetamine-type stimulants (ATSs) were the most common co-occurring substances (22.8% forensic, 46.9% clinical), followed by cannabis (24.1% forensic, 26.5% clinical).
• Opioid co-use was infrequent. PGB detection varied significantly by month (p < 0.001).

Conclusions:

• Contrary to previous findings, stimulants (ATSs) and cannabis are more prevalent co-used substances with PGB than opioids.
• A significant proportion of PGB detections in probation cases, often as a single substance, suggests potential use to circumvent legal scrutiny.
• Laboratories must adapt testing panels to include emerging drugs of abuse like PGB, recognizing regional and cultural variations in substance use patterns.