Pharmacology of Addictive Substances Flashcards

Which neurotransmitter is most centrally involved in the mesolimbic reward pathway associated with substance use disorders?

Answer: Dopamine

Dopamine is the primary neurotransmitter in the mesolimbic reward pathway, and surges in dopamine release are the central mechanism underlying the reinforcing effects of addictive substances.

Which of the following correctly describes the primary mechanism of action of opioids in the central nervous system?

Answer: They bind to mu, kappa, and delta opioid receptors

Opioids exert their analgesic and euphoric effects primarily by binding to mu-opioid receptors (as well as kappa and delta receptors) distributed throughout the brain and peripheral nervous system.

Alcohol produces CNS depression primarily by which pharmacological mechanism?

Answer: Enhancing GABA-A inhibitory activity and inhibiting NMDA glutamate receptors

Alcohol enhances inhibitory GABA neurotransmission and inhibits excitatory glutamate activity at NMDA receptors, producing the characteristic CNS depressant effects.

In addiction pharmacology, 'tolerance' is best defined as:

Answer: The requirement for increasing doses to achieve the same effect previously produced by a lower dose

Tolerance develops when repeated substance exposure leads to diminished pharmacological effects, requiring progressively higher doses to achieve the original response.

Which opioid's long half-life (24–36 hours) produces withdrawal symptoms that are less intense but more prolonged compared to short-acting opioids?

Answer: Methadone

Methadone's long half-life means blood levels decline slowly, producing a withdrawal syndrome that is milder in peak intensity but extends over a longer period than short-acting opioids.

The concurrent use of two or more psychoactive substances is clinically referred to as:

Answer: Polysubstance use

Polysubstance use describes the simultaneous or concurrent use of multiple psychoactive substances, which complicates assessment, treatment planning, and withdrawal management.

Stimulants such as cocaine and amphetamines primarily produce euphoria by which mechanism?

Answer: Blocking the reuptake of dopamine, norepinephrine, and serotonin

Stimulants block monoamine reuptake transporters, causing accumulation of dopamine, norepinephrine, and serotonin in the synapse, which produces intense euphoria and increased arousal.