buprenorphine-3-o-glucuronide and norbuprenorphine

This study examined drug interactions between buprenorphine, a partial opioid agonist used for opioid dependence treatment and pain management, and the protease inhibitors (PIs) darunavir-ritonavir and fosamprenavir-ritonavir.. The pharmacokinetics of buprenorphine and its metabolites and symptoms of opioid withdrawal or excess were compared in opioid-dependent, buprenorphine-naloxone-maintained, human immunodeficiency virus (HIV)-negative volunteers (11 for darunavir-ritonavir and 10 for fosamprenavir-ritonavir) before and after 15 days of PI administration. PI pharmacokinetics and adverse effects were compared between the buprenorphine-maintained participants and an equal number of sex-, age-, race-, and weight-matched, healthy, non-opioid-dependent volunteers who received darunavir-ritonavir or fosamprenavir-ritonavir but not buprenorphine.. There were no significant changes in buprenorphine or PI plasma levels and no significant changes in medication adverse effects or opioid withdrawal. Increased concentrations of the inactive metabolite buprenorphine-3-glucuronide suggested that darunavir-ritonavir and fosamprenavir-ritonavir induced glucuronidation of buprenorphine.. Dose adjustments are not likely to be necessary when buprenorphine and darunavir-ritonavir or fosamprenavir-ritonavir are coadministered for the treatment of opioid dependence and HIV disease.

Topics: Anti-HIV Agents; Area Under Curve; Buprenorphine; Carbamates; Darunavir; Drug Interactions; Female; Furans; Half-Life; History, 16th Century; History, 17th Century; Humans; Male; Naloxone; Narcotic Antagonists; Opiate Substitution Treatment; Organophosphates; Protease Inhibitors; Ritonavir; Sulfonamides

Buprenorphine is an opioid drug that has been used to treat opioid dependence on an outpatient basis, and is also prescribed for managing moderate to severe pain. Some formulations of buprenorphine also contain naloxone to discourage misuse. The major metabolite of buprenorphine is norbuprenorphine. Both compounds are pharmacologically active and both are extensively metabolized to their glucuronide conjugates, which are also active metabolites. Direct quantitation of the glucuronide conjugates in conjunction with free buprenorphine, norbuprenorphine, and naloxone in urine can distinguish compliance with prescribed therapy from specimen adulteration intended to mimic compliance with prescribed buprenorphine. This chapter quantitates buprenorphine, norbuprenorphine, their glucuronide conjugates and naloxone directly in urine by liquid chromatography tandem mass spectrometry (LC-MS/MS). Urine is pretreated with formic acid and undergoes solid phase extraction (SPE) prior to analysis by LC-MS/MS.

Topics: Analgesics, Opioid; Buprenorphine; Chromatography, Liquid; Drug Monitoring; Humans; Naloxone; Narcotic Antagonists; Solid Phase Extraction; Tandem Mass Spectrometry

A sensitive liquid chromatographic-high-resolution mass spectrometric (LC-HR-MS) assay for buprenorphine and its urinary metabolites has been developed that requires minimal sample preparation. The results obtained have been compared with those given by (i) cloned enzyme donor immunoassay (CEDIA) and (ii) homogeneous enzyme immunoassay (HEIA) in the analysis of patient urines submitted for buprenorphine analysis. Centrifuged urine (100 µL) was diluted with internal standard solution (25 µL) + LC eluent (875 µL), and 50 µL of the prepared sample were analyzed (Accucore Phenyl-Hexyl column). MS detection was in alternating positive and negative mode using heated electrospray ionization (ThermoFisher Q Exactive). Intra- and inter-assay accuracy and precision were 104-128 and <11%, respectively, at 5 µg/L. Limits of detection were 1.3 µg/L (buprenorphine, norbuprenorphine and buprenorphine glucuronide) and 2.5 µg/L (norbuprenorphine glucuronide). Immunoassay sensitivity and selectivity were 97 and 100% (HEIA) and 99 and 84% (CEDIA), respectively, compared with LC-HR-MS. In 120 patient urines, norbuprenorphine glucuronide was easily the most abundant analyte except when adulteration with buprenorphine had occurred. The median immunoreactive buprenorphine species present (unhydrolysed urine) were 7.5 and 13% for HEIA and CEDIA, respectively. However, codeine, dihydrocodeine, morphine and morphine-3-glucuronide did not interfere in the HEIA assay.

Topics: Analgesics, Opioid; Buprenorphine; Calibration; Chromatography, Liquid; Humans; Immunoenzyme Techniques; Narcotic Antagonists; Reproducibility of Results; Sensitivity and Specificity; Spectrometry, Mass, Electrospray Ionization; Substance Abuse Detection

A liquid chromatographic/electrospray ionization tandem mass spectrometric method for the quantification of buprenorphine (BUP), norbuprenorphine (NBUP), buprenorphine-3-beta-D-glucuronide (BUPG) and norbuprenorphine-3-beta-D-glucuronide (NBUPG) in serum samples was developed and validated. Pre-treatment of BUP and NBUP was by liquid-liquid extraction, while glucuronides were favourably isolated by solid phase extraction. Separation in 2 separate runs (2 x 5 min) was achieved using isocratic elution. The method was applied to 20 authentic serum specimens collected for law enforcement purposes where BUP intake had been indicated. The parent drug was not detectable in half of the specimens at a lower limit of detection of 0.2 ng/mL, whereas NBUP could be determined from any sample but one. NBUPG is the major metabolite present, which could be identified along with BUPG in all samples under investigation. In authentic specimens it could be advisable to monitor BUP metabolites along with the parent drug.

Topics: Analgesics, Opioid; Buprenorphine; Chromatography, Liquid; Forensic Toxicology; Humans; Law Enforcement; Spectrometry, Mass, Electrospray Ionization; Substance Abuse Detection; Tandem Mass Spectrometry

We tested the hypothesis that primary cultures of human hepatocytes could predict potential drug interactions with methadone and buprenorphine. Hepatocytes (five donors) were preincubated with dimethyl sulfoxide (DMSO) (vehicle), rifampin, or nelfinavir before incubation with methadone or buprenorphine. Culture media (0-60 min) was analyzed by liquid chromatography-tandem mass spectrometry for R- and S-methadone and R- and S-2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) or for buprenorphine, norbuprenorphine, and their glucuronides [buprenorphine-3-glucuronide (B-3-G) and norbuprenorphine-3-glucuronide (N-3-G)]. R- and S-EDDP were detected in three of five, four of five, and five of five media from cells pretreated with DMSO, nelfinavir, and rifampin. R-EDDP increased 3.1- and 26.5-fold, and S-EDDP increased 2.5- and 21.3-fold after nelfinavir and rifampin. The rifampin effect was significant. B-3-G production was detected in media of all cells incubated with buprenorphine and accounted for most of the buprenorphine loss from culture media; it was not significantly affected by either pretreatment. Norbuprenorphine and N-3-G together were detected in three of five, four of five, and five of five donors pretreated with DMSO, nelfinavir and rifampin, and norbuprenorphine in one of five, one of five, and two of five donors. Although there was a trend for norbuprenorphine (2.8- and 4.9-fold) and N-3-G (1.7- and 1.9-fold) to increase after nelfinavir and rifampin, none of the changes were significant. To investigate low norbuprenorphine production, buprenorphine was incubated with human liver and small intestine microsomes fortified to support both N-dealkylation and glucuronidation; N-dealkylation predominated in small intestine and glucuronidation in liver microsomes. These studies support the hypothesis that methadone metabolism and its potential for drug interactions can be predicted with cultured human hepatocytes, but for buprenorphine the combined effects of hepatic and small intestinal metabolism are probably involved.

Topics: Adult; Aged; Analgesics, Opioid; Antibiotics, Antitubercular; Biotransformation; Buprenorphine; Cells, Cultured; Chromatography, Liquid; Dealkylation; Drug Interactions; Female; Glucuronides; Hepatocytes; HIV Protease Inhibitors; Humans; Intestinal Mucosa; Kinetics; Male; Methadone; Microsomes, Liver; Middle Aged; Nelfinavir; Pyrrolidines; Rifampin; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

The opioid partial agonist medication, buprenorphine (BUP), and its primary metabolite, norbuprenorphine (NBUP), are extensively glucuronidated. Sensitive analytical methods that include determination of buprenorphine-3-glucuronide (BUPG) and norbuprenorphine-3-glucuronide (NBUPG) are needed to more fully understand the metabolism and pharmacokinetics of buprenorphine. A method has now been developed that uses solid-phase extraction followed by liquid chromatography-electrospray ionization-tandem mass spectrometry. BUP-d4, NBUP-d3, and morphine-3-glucuronide-d3 were used as internal standards. The lower limit of quantitation was 0.1 and 0.5 ng/mL for each of the analytes in 1-mL of human plasma and urine, respectively, except for NBUP in urine in which it was 2.5 ng/mL. The analytes were stable under the following conditions: plasma and urine at room temperature, up to 20 hours; plasma and urine at -20 degrees C for 119 and 85 days, respectively; plasma freeze-thaw, up to 3 cycles; processed sample, up to 96 hours at -20 degrees C and up to 48 hours on the autosampler; stock solutions at room temperature and at -20 degrees C, up to 6 hours and 128 days, respectively. In plasma collected from 5 subjects on maintenance daily sublingual doses of 16 mg BUP and 4 mg naloxone, respective 0- to 24-hour areas under the curve were 32, 88, 26, and 316 ng/mL x h for BUP, NBUP, BUPG, and NBUPG. In urine samples respective percent of daily dose excreted in the 24-hour urine were 0.014%, 1.89%, 1.01%, and 7.76%. This method allowed us to determine that NBUPG is a major metabolite present in plasma and urine of BUP. Because urinary elimination is limited ( approximately 11% of daily dose), the role of NBUPG in total clearance of buprenorphine is not yet known.

Topics: Administration, Sublingual; Buprenorphine; Chromatography, High Pressure Liquid; Drug Stability; Humans; Narcotic Antagonists; Reproducibility of Results; Spectrometry, Mass, Electrospray Ionization; Temperature; Time Factors

A liquid chromatographic/electrospray ionization tandem mass spectrometric method for the quantification of the synthetic opiate buprenorphine (BUP), norbuprenorphine (NBUP), buprenorphine-3-beta-D-glucuronide (BUP-3-G) and norbuprenorphine-3-beta-D-glucuronide (NBUP-3-G) in human plasma was developed and validated. Identification and quantification were based on the following transitions: m/z 468 to 396 and 414 for BUP, m/z 414 to 326 and 340 for NBUP, m/z 644 to 468 for BUP-3-G and m/z 590 to 414 for NBUP-3-G. Calibration by linear regression analysis utilized deuteratated internal standards and a weighting factor of 1/x. The method was accurate and precise across a linear dynamic range of 0.6-50.0 ng ml(-1). Pretreatment of plasma samples using solid-phase extraction was sufficient to limit matrix suppression to <30% for all four analytes. The method proved to be suitable for the quantification of BUP and the related metabolites in plasma samples collected from BUP-maintained study participants.

Topics: Buprenorphine; Chromatography, High Pressure Liquid; Female; Humans; Narcotic Antagonists; Pregnancy; Reproducibility of Results; Spectrometry, Mass, Electrospray Ionization

For the first time, an LC-MS-MS method has been developed for the simultaneous analysis of buprenorphine (BUP), norbuprenorphine (NBUP), and buprenorphine-glucuronide (BUPG) in plasma. Analytes were isolated from plasma by C18 SPE and separated by gradient RP-LC. Electrospray ionization and MS-MS analyses were carried out using a PE-Sciex API-3000 tandem mass spectrometer. The m/z 644-->m/z 468 transition was monitored for BUPG, whereas for BUP, BUP-d4, NBUP, and NBUP-d3 it was necessary to monitor the surviving parent ions in order to achieve the required sensitivity. The method exhibited good linearity from 0.1 to 50 ng/ml (r2> or =0.998). Extraction recovery was higher than 77% for BUPG and higher than 88% for both BUP and NBUP. The LOQ was established at 0.1 ng/ml for the three analytes. The method was validated on plasma samples collected in a controlled intravenous and sublingual buprenorphine administration study. Norbuprenorphine-glucuronide was also tentatively detected in plasma by monitoring the m/z 590-->m/z 414 transition.

Topics: Analgesics, Opioid; Buprenorphine; Chromatography, Liquid; Humans; Mass Spectrometry; Quality Control

The disposition of buprenorphine has been studied in two patient groups to assess the influence of impaired renal function on the metabolism of buprenorphine and two of its metabolites, buprenorphine-3-glucuronide (B3G) and norbuprenorphine (NorB). A single i.v. dose of 0.3 mg was given to 15 patients (nine with dialysis-dependent renal failure) undergoing lower abdominal or peripheral body surface surgery. Blood was sampled up to 24 h. Concentrations of buprenorphine, B3G and NorB were assayed by a differential radioimmunoassay technique. There were no differences in buprenorphine kinetics between anaesthetized healthy patients and those with renal impairment: mean elimination half-lives 398 and 239 min; clearance 651 and 988 ml min-1; apparent volume of distribution at steady state 313 and 201 litre, respectively. Both metabolites were undetectable following the single i.v. dose. In a second group of 20 patients (eight with renal impairment), buprenorphine was administered by continuous infusion for provision of analgesia and control of ventilation in the ITU (median infusion rate 161 micrograms h-1 (range 36-230 micrograms h-1) for a median duration of 30 h (2-565 h). Buprenorphine clearance in patients with normal and impaired renal function was similar (934 and 1102 ml min-1, respectively), as were dose-corrected plasma concentrations of buprenorphine. In patients with renal failure, plasma concentrations of NorB were increased by a median of four times, and B3G concentrations by a median of 15 times.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anesthesia, General; Buprenorphine; Critical Care; Female; Humans; Infusions, Intravenous; Kidney Diseases; Male; Middle Aged