Buprenorphine and Norbuprenorphine, Urine
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Clinically, buprenorphine is utilized as a substitution therapy for opioid dependance and as an analgesic. Buprenorphine is a partial agonist of the mu-opioid receptor. These mu binding sites are discretely distributed in the human brain, spinal cord, and other tissue. The clinical effects of mu receptor agonists are sedation, euphoria, respiratory depression, and and analgesia. As a partial mu receptor agonist, buprenorphine’s clinical effects are decreased, giving buprenorphine a wider safety margin.(1) Buprenorphine has a prolonged duration of activity. The combination of decreased clinical effects and prolonged activity gives buprenorphine the added advantage of a delayed and decreased withdrawal syndrome, compared to other opioids.(1) Compared to morphine, buprenorphine is 25 to 40 times more potent.(1) As with any opioid, abuse is always a concern. To reduce illicit use of buprenorphine, it is available mixed with naloxone in a ratio of 4:1. When the combination is taken as prescribed, only small amounts of naloxone will be absorbed. However, if the combination is transformed into the injectable form, naloxone then acts as an opioid receptor antagonist.
Buprenorphine is metabolized through N-dealkylation to norbuprenorphine through cytochrome P450 3A4. Both parent and metabolite then undergo glucuronidation. Norbuprenorphine is an active metabolite possessing one fifth of the potency of its parent. The glucuronide metabolites are inactive.(1)
The primary clinical utility of quantification of buprenorphine in urine is to identify patients that have strayed from opioid dependance therapy.
Monitoring of compliance utilizing buprenorphine
Detection and confirmation of the illicit use of buprenorphine
The presence of buprenorphine >0.5 ng/mL or norbuprenorphine >0.5 ng/mL is a strong indicator that the patient has used buprenorphine.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Urine concentrations do not correlate well with serum drug levels and are not intended for therapeutic drug management.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Elkader A, Spuroule B: Buprenorphine Clinical Pharmacokinetics in the Treatment of Opioid Dependence. Clin Pharmacokinet 2005;44(7):661-680
2. Grimm D, Pauly E, Poschl J, et al: Buprenorphine and Norbuprenorphine Concentrations in Human Breast Milk Samples Determined by Liquid Chromatography-Tandem Mass Spectrometry. Ther Drug Monit 2005;27(4)526-530
3. Kacinko S, Shakleya D, Huestis A: Validation and Application of a Method for the Determination of Buprenorphine, Norbuprenorphine, and Their Glucuronide Conjugates in Human Meconium. Anal Chem 2008;80(1)246-252
4. Concheiro M, Shakleya M, Huestis A: Simultaneous quantification buprenorphine, norbuprenorphine, buprenorphine-glucuronide and norbuprenorphine-glucuronide in human umbilical cord by liquid chromatography tandem mass spectrometry, Forensic Sci