Drugs of Abuse - Opiates

Drugs of Abuse - Opiates

 

Opiate drugs, while effective analgesics, produce dependency, severe withdrawal effects, and can result in overdose which may result in death. They are analytically monitored in pain management programs during treatment/rehabilitation to assess exposure of neonates to maternal drug abuse during gestation and whenever health professionals suspect abuse.

  • All opiates are capable of producing tolerance and withdrawal
  • Approximately 1 million Americans are opiate-dependent
  • Users often abuse other substances
  • Effects on organs include:
    • Central nervous system
      • Opiate euphoria
      • Withdrawal
    • Respiratory
      • Depression of respiratory drive
    • Gastrointestinal
      • Nausea
      • Emesis
      • Constipation
  • Addiction is related to environmental factors; however, genetics may contribute

The interpretation of opiate drug abuse testing is complicated because some prescription opiates are metabolized to other prescription opiates; their presence may be due to metabolism and not from additional opiate use. The following information assists in the correct interpretation of opiate drug abuse testing (if uncertain, call medical director of lab performing the test)

  • Opiate metabolism (percentages reported are from an ARUP database study, 2006)  Note: The following percentages pertain to opiates in urine
    • Major pathways
      • Morphine from codeine
        • When free morphine, as a percent of free codeine in a specimen is less 55%, morphine may have come from metabolism of codeine, and not from separate use of morphine
        • Interpretation of drug abuse due to the presence of morphine may not be justified
      • Hydromorphone from hydrocodone
        • When free hydromorphone, as a percent of hydrocodone in a specimen is less than 30%, the hydromorphone may have come from metabolism of hydrocodone, and not from separate use of hydromorphone
        • Interpretation of drug abuse due to the presence of hydromorphone may not be justified
      • Heroin metabolism
        • When 6-acetylmorphine is present along with morphine, this is definitive evidence that the patient has used heroin
  • Minor pathways (percentages reported are from an ARUP database study, 2006)  Note: The following percentages pertain to opiates in urine
    • Hydrocodone from codeine
      • When hydrocodone as a percent of free codeine in a specimen is less than 40%, hydrocodone may have come from metabolism of codeine and not from the separate use of hydrocodone
      • Interpretation of drug abuse due to the presence of hydrocodone may not be justified
    • Hydromorphone from morphine
      • When free hydromorphone as a percent of free morphine is less than 25%, hydromorphone may have come from metabolism of morphine and not from separate use of hydromorphone
      • Interpretation of drug abuse due to the presence of hydromorphone may not be justified
  • Oxycodone
    • Oxycodone does not derive from any other prescription opiate
    • Its presence is definitive evidence that the patient has taken oxycodone

Risk Factors

  • Groups at particular risk – chronic pain management patients, health care providers, drug abusers who purchase street drugs or acquire prescription drugs illegally.