morphine-3-glucuronide and hydromorphone-3-glucuronide

Current hair testing methods that rely solely on quantification of parent drug compounds are unable to definitively distinguish between drug use and external contamination. One possible solution to this problem is to confirm the presence of unique drug metabolites that cannot be present through contamination, such as phase II glucuronide conjugates. This work demonstrates for the first time that codeine-6-glucuronide, hydromorphone-3-glucuronide, oxymorphone-3-glucuronide, morphine-3-glucuronide and morphine-6-glucuronide are present at sufficient concentrations to be quantifiable in hair of opioid users and that their concentrations generally increase as the concentrations of the corresponding parent compounds increase. Here, we present a validated liquid chromatography tandem mass spectrometry method to quantify codeine-6-glucuronide, dihydrocodeine-6-glucuronide, hydromorphone-3-glucuronide, morphine-3-glucuronide, morphine-6-glucuronide, oxymorphone-3-glucuronide, codeine, dihydrocodeine, dihydromorphine, hydrocodone, hydromorphone, morphine, oxycodone, oxymorphone and 6-acetylmorphine in human hair. The method was used to analyze 46 human hair samples from known drug users that were confirmed positive for opioids by an independent laboratory. Glucuronide concentrations in samples positive for parent analytes ranged from ~1 to 25 pg/mg, and most samples had glucuronide concentrations in the range of ~1 to 5 pg/mg. Relative to the parent concentrations, the average concentrations of the four detected glucuronides were as follows: codeine-6-glucuronide, 2.33%; hydromorphone-3-glucuronide, 0.94%; oxymorphone-3-glucuronide, 0.77%; morphine 3-glucuronide, 0.59%; and morphine-6-glucuronide, 0.93%.

Topics: Chromatography, Liquid; Codeine; Glucuronates; Hair; Humans; Hydromorphone; Limit of Detection; Morphine Derivatives; Opioid-Related Disorders; Reproducibility of Results; Specimen Handling; Substance Abuse Detection; Tandem Mass Spectrometry

In humans, hydromorphone (HMOR) is metabolised principally by conjugation with glucuronic acid to form hydromorphone-3-glucuronide (H3G), a close structural analogue of morphine-3-glucuronide (M3G), the major metabolite of morphine. In a previous study we described the biochemical synthesis of H3G together with a preliminary evaluation of its pharmacology which revealed that it is a neuroexcitant in rats in a manner analogous to M3G. Thus the aims of the current study were to quantify the neuro-excitatory behaviours evoked by intracerebroventricular (icv) H3G in the rat and to define its potency relative to M3G. Groups of adult male Sprague-Dawley rats received icv injections (1 microL) of H3G (1 - 3 microg), M3G (2 - 7 microg) or vehicle via a stainless steel guide cannula that had been implanted stereotaxically seven days prior to drug administration. Behavioural excitation was monitored by scoring fifteen different behaviours (myoclonic jerks, chewing, wet-dog-shakes, rearing, tonic-clonic-convulsions, explosive motor behaviour, grooming, exploring, general activity, eating, staring, ataxia, righting reflex, body posture, touch evoked agitation) immediately prior to icv injection and at the following post-dosing times: 5, 15, 25, 35, 50, 65 and 80 min. H3G produced dose-dependent behavioural excitation in a manner analogous to that reported previously for M3G by our laboratory and reproduced herein. H3G was found to be approximately 2.5-fold more potent than M3G, such that the mean (+/- S.D.) ED50 values were 2.3 (+/- 0.1) microg and 6.1 (+/- 0.6) microg respectively. Thus, our data clearly imply that if H3G crosses the BBB with equivalent efficiency to M3G, then the myoclonus, allodynia and seizures observed in some patients dosed chronically with large systemic doses of HMOR, are almost certainly due to the accumulation of sufficient H3G in the central nervous system, to evoke behavioural excitation.

Topics: Animals; Behavior, Animal; Central Nervous System Stimulants; Dose-Response Relationship, Drug; Glucuronates; Hydromorphone; Injections, Intraventricular; Male; Morphine Derivatives; Motor Activity; Rats; Rats, Sprague-Dawley