Metabolism and Disposition of Prescription Opioids: A Review.

Article Details

Citation

DePriest AZ, Puet BL, Holt AC, Roberts A, Cone EJ

Metabolism and Disposition of Prescription Opioids: A Review.

Forensic Sci Rev. 2015 Jul;27(2):115-45.

PubMed ID
26227254 [ View in PubMed
]
Abstract

Opioid analgesics are commonly prescribed for acute and chronic pain, but are subject to abuse. Consequently, toxicology testing programs are frequently implemented for both forensic and clinical applications. Understanding opioid metabolism and disposition is essential for assessing risk of toxicity and, in some cases, providing additional information regarding risk of therapeutic failure. Opioids significantly metabolized by the cytochromeP450 (CYP450) enzyme system maybe subjectto drug-drug interactions, including codeine, hydrocodone, oxycodone, fentanyl, meperidine, methadone, buprenorphine, and tramadol. CYP2D6 metabolism is polymorphic, and pharmacogenetic testing has been investigated for codeine, tramadol, oxycodone, and hydrocodone. CYP2B6 pharmacogenetic testing of methadone may reduce the risk of cardiac toxicity associated with the S-enantiomer. Opioids metabolized primarily by uridine 5'-diphospho-glucuronsyltransferase (UGT) enzymes include morphine, hydromorphone, dihydrocodeine, oxymorphone, levorphanol, and tapentadol. Parent and metabolite disposition is described for blood, oral fluid, and urine. Parent drug is most commonly detected in blood and oral fluid, whereas metabolites typically predominate in urine. Oral fluid/blood ratios exceed 1 for most opioids, making this an excellent alternative matrix for testing of this drug class. Metabolites of codeine, hydrocodone, and oxycodone are commercially available, and knowledge of metabolism is necessary for correct interpretation.

DrugBank Data that Cites this Article

Drugs
Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
OxycodoneCytochrome P450 2D6ProteinHumans
Unknown
Substrate
Details
OxycodoneCytochrome P450 3A4ProteinHumans
Unknown
Substrate
Details
OxycodoneCytochrome P450 3A5ProteinHumans
Unknown
Substrate
Details
Drug Reactions
Reaction
Details
Details
Details
Details
Details
Details