Week 3 Pt. II

Opiates Overview

  • Opiates are drugs derived from opium, which comes from the poppy plant.

  • Major medical use: treatment of severe pain.

  • Effects: depress respiration, lower body temperature, cause capillary constriction, and induce euphoria.

  • Common opiates: Morphine and codeine derived directly from opium.

Historical Context

Early History

  • Opium derived from Papaver somniferum, native to the Middle East, cultivated extensively in Asia and the Middle East.

  • The sap of opiates becomes thick, gummy opium after drying; consumed orally or smoked.

Ancient Civilizations

  • Ancient Egyptians utilized opiates for medicinal purposes 3,500 years ago (e.g., Therapeutic Papyrus of Thebes).

  • Opium was widely used in ancient Egyptian, Greek, and Roman societies for various medical conditions.

19th Century Use

  • In Europe and North America, opium was primarily ingested orally in liquid form, termed opium eating/drinking for medical use.

  • Awareness of addiction properties in opiate drugs emerged.

  • 1803: F.W. Serturner developed a method to extract morphine from opium, with morphine being 10 times more potent.

  • Development of hypodermic syringe led to increased morphine dependence; used heavily post-surgery.

20th Century and Current Landscape

Regulatory Changes

  • Awareness of opiate dangers led to legislative measures:

    • Harrison Narcotics Act (1914) in the U.S.

    • Canada's Opium Act (1908) and subsequent Opium and Narcotic Drug Act (1929).

  • Opiate addiction previously widespread among social classes; illegal use prevalent in large cities.

Heroin and Opiate Crisis

  • Heroin emerged as the drug of choice for many, leading to expansive criminal networks for supply.

  • Presently, most heroin originates from Southwest Asia, with Afghanistan being a major producer (90% of global opium).

Prescription Opiate Abuse

  • Although heroin use plateaued, prescription opiate use surged, increasing admissions to drug treatment and emergency rooms.

  • Canada ranks third globally in prescription opioid use, behind the U.S. and Germany.

OxyContin and OxyNEO

  • OxyContin's high doses of oxycodone led to significant abuse, users frequently crushing tablets for injection or inhalation.

  • OxyNEO has replaced OxyContin in Canada.

Mechanisms of Opiate Action

Absorption and Distribution

  • Opiates can be absorbed via the gastrointestinal tract, intravenously, intranasally, or through smoking.

  • Once in circulation, they distribute to organs like kidneys, lungs, liver, and brain.

  • Heroin converts to morphine in the brain.

Metabolism and Excretion

  • Most opiates metabolized in the liver, rapidly excreted via kidneys (90% within one day).

Acute Effects of Opiates

  • Opiates cause euphoria, impair social interaction, and cognitive function.

  • Physiological effects include respiratory depression, lowered body temperature, and pinpoint pupils commonly indicate overdose.

  • Risks magnified when combined with other depressant drugs.

Chronic Effects and Dependence

Tolerance

  • Regular use leads to tolerance, reducing the rewarding effects.

Withdrawal

  • Initial use driven by the desire for the euphoric rush later shifts to avoid unpleasant withdrawal symptoms.