What are the mechanisms of illicit drug use aside from spiraling?

Mechanisms of Illicit Drug Use Beyond Spiraling

The primary mechanisms of illicit drug use include injection, inhalation, sniffing, smoking, and ingestion, with each route having distinct health risks and patterns of use. 1

Routes of Administration

Injection

• Involves direct introduction of substances into the bloodstream
• Highest bioavailability of administered drugs 2
• Associated with highest risk for bloodborne infections (HIV, hepatitis C)
• Approximately 9-12% of new HIV cases and 50% of new hepatitis C cases in the US are associated with injection drug use 1

Inhalation/Smoking

• Provides most rapid delivery of drugs to the brain 2
• Common for substances like crack cocaine, methamphetamine, and marijuana
• Associated with respiratory damage and carcinogenesis 2
• Allows for rapid absorption and quick onset of effects

Sniffing/Intranasal

• Involves absorption through nasal mucosa
• Common for powdered cocaine, ketamine, and some prescription medications
• Can cause damage to nasal tissues and septum perforation
• Intermediate speed of onset compared to injection and smoking

Oral Ingestion

• Involves swallowing substances (pills, liquids)
• Slower onset due to first-pass metabolism
• Common for MDMA/ecstasy, LSD, and many prescription medications
• Generally lower bioavailability compared to other routes 2

Biochemical Mechanisms

Electron Transfer and Oxidative Stress

• Many drugs of abuse function through electron transfer (ET) mechanisms
• Generate reactive oxygen species (ROS) causing oxidative stress
• Common ET functionalities include quinones and iminiums 3
• Specific examples:
  • Cocaine: forms iminium, nitroxyl radical, and nitrosonium metabolites
  • Amphetamines: metabolize to catechol structures capable of redox cycling
  • Opioids: morphine and heroin also function via catechol pathways 3

Neurotransmitter Interactions

• Different classes of drugs affect specific neurotransmitter systems:
  • Stimulants (cocaine, amphetamines): increase dopamine, norepinephrine
  • Opioids: activate mu-opioid receptors
  • Cannabis: acts on cannabinoid receptors
  • MDMA/ecstasy: increases serotonin, dopamine, and norepinephrine 4

Behavioral and Social Mechanisms

Polysubstance Use

• More than 50% of people who inject drugs illicitly use multiple substances through various routes 1
• Genetic overlap between cannabis use and other illicit drug use suggests shared genetic predisposition 5
• Increases risk of drug interactions and overdose 1

Exchange of Sex for Drugs

• Particularly associated with crack cocaine use
• Increases risk for HIV and other STDs 1
• Creates complex social and health challenges

Impaired Judgment

• Drug use impairs decision-making capacity
• Increases likelihood of engaging in risky sexual behaviors 1
• Creates cycle of risk-taking behavior

Environmental and Structural Factors

Limited Access to Sterile Equipment

• Contributes to sharing of injection equipment
• Increases risk of bloodborne infections 1

Unstable Living Conditions

• Common among people who use drugs illicitly
• Complicates treatment and recovery efforts 1

Fear of Legal Consequences

• Discourages seeking medical help during overdose
• Contributes to delayed treatment and increased mortality 1
• Persons who inject drugs can overdose when injecting alone, often in settings where peers are not trained in overdose prevention 1

Health Consequences

Infectious Disease Transmission

• HIV, hepatitis C, STDs, and tuberculosis are prevalent among people who use drugs illicitly
• Route-specific risks: injection (bloodborne pathogens), non-injection (sexual transmission)
• HSV-2 prevalence is 38-61% among people who use drugs illicitly compared to 17% in general population 1

Overdose

• Leading cause of mortality among people who inject drugs
• Drug overdose death rates increased nearly fivefold from 1990-2007
• Opioid pain medications account for highest number of unintentional overdose deaths, followed by cocaine and heroin 1

Cardiovascular Events

• Cocaine and amphetamines have strongest association with stroke
• Even young, healthy people are predisposed to ischemic or hemorrhagic stroke with certain substances 6

Understanding these diverse mechanisms of illicit drug use is essential for developing effective prevention and treatment strategies that address the complex biological, behavioral, and social factors involved in substance use disorders.