The international journal of neuropsychopharmacology
August 1, 2010
Nicolas Tournier, Lucie Chevillard, Bruno Megarbane et al.
122 citations
Several drugs used in addiction treatment and substances of abuse inhibit the efflux transporters P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) in vitro, which could alter their distribution in the body, including across the blood-brain barrier. Norbuprenorphine, buprenorphine, methadone, ibogaine, and THC inhibited P-gp in a concentration-dependent manner, with norbuprenorphine being the strongest. Buprenorphine, norbuprenorphine, ibogaine, and THC inhibited BCRP. Cocaine, amphetamine, nicotine, morphine, and others did not inhibit either transporter. Norbuprenorphine and methadone were transported by P-gp, but no tested compounds were transported by BCRP. The clinical relevance of norbuprenorphine's interaction with P-gp remains unclear.
Journal of Analytical Toxicology
October 1, 2009
T. T. Abraham, Allan J. Barnes, Richie H. Lowe et al.
56 citations
After a single oral dose of MDMA (ecstasy), the drug and its metabolites are excreted in urine over an extended period, with the metabolite HMMA detectable longer than MDMA itself. In a double-blind study, healthy adult MDMA users received placebo, 1.0 mg/kg, or 1.6 mg/kg doses. From 916 urine specimens provided by 16 participants, median peak concentrations after the higher dose were 21,470 ng/mL for MDMA and 20,793 ng/mL for HMMA, with HMMA's last detection exceeding MDMA's by over 33 hours. In the first 24 hours, 30.2-34.3% of total urinary excretion occurred. Including HMMA in urine testing improves detection of MDMA exposure but requires hydrolysis of the sample.
Clinical Chemistry
July 20, 2006
Stéphane Pirnay, T. T. Abraham, Marilyn A. Huestis
29 citations
A sensitive gas chromatography-mass spectrometry method was developed and validated to simultaneously measure MDEA, MDMA, and its metabolites (HMA, MDA, HMMA) in human urine. The method involves acid hydrolysis of 1 mL urine, solid-phase extraction, and derivatization before analysis. Limits of quantification were 25 μg/L for all analytes, with linear calibration up to 5000 μg/L. Extraction efficiencies exceeded 85.5%, and imprecision (coefficient of variation) was below 15% at tested concentrations. The assay meets federal workplace drug testing guidelines for these substances.
Journal of Analytical Toxicology
October 1, 2006
Stéphane Pirnay, T. T. Abraham, Richie H. Lowe et al.
23 citations
Acid hydrolysis recovers more MDMA urinary metabolites than enzymatic hydrolysis with beta-glucuronidase from either E. coli or Helix pomatia. Acid hydrolysis yielded 40.0% and 39.3% higher HMA recovery compared to E. coli and H. pomatia hydrolysis, respectively. E. coli beta-glucuronidase gave 17.1% and 26.5% greater MDA recovery than acid hydrolysis and H. pomatia hydrolysis. HMMA recovery by acid hydrolysis was 336.1% and 159.8% greater than E. coli and H. pomatia beta-glucuronidase. Optimal conditions were 100 µL hydrochloric acid per 1 mL urine incubated at 120°C for 40 minutes. Based on recovery, time, availability, and cost, acid hydrolysis is preferred.