Pharmacology of Addictive Substances Flashcards

A patient with cocaine use disorder asks about FDA-approved pharmacotherapy. Which statement is most accurate?

Answer: There are currently no FDA-approved medications specifically for cocaine use disorder

As of 2025, no medications are FDA-approved specifically for cocaine use disorder, though several (topiramate, disulfiram) show limited evidence in research settings.

Nicotine replacement therapy (NRT) works by delivering nicotine via a non-tobacco route. What is the primary therapeutic goal of NRT?

Answer: Reducing withdrawal symptoms and craving without the harmful tobacco combustion products

NRT reduces nicotine withdrawal and craving by providing controlled nicotine exposure, allowing the patient to quit smoking without the harmful chemicals in tobacco smoke.

Inhalant abuse (e.g., toluene) produces CNS effects primarily through which mechanism?

Answer: Potentiation of GABA-A and inhibition of NMDA receptors, similar to alcohol

Toluene and other inhalants potentiate GABA-A receptors and block NMDA receptors, producing CNS depression, disinhibition, and euphoria similar to alcohol intoxication.

Which pharmacological property of kratom makes it relevant to opioid use disorder treatment discussions?

Answer: Kratom's active alkaloids act as partial agonists at mu-opioid receptors

Kratom's active alkaloids (mitragynine, 7-hydroxymitragynine) are partial mu-opioid receptor agonists, producing opioid-like effects and carrying dependence and withdrawal risk.

Clonidine is sometimes used in opioid withdrawal management. What is its primary mechanism in this context?

Answer: It stimulates alpha-2 adrenergic receptors, suppressing noradrenergic hyperactivity that drives withdrawal symptoms

Opioid withdrawal activates the locus coeruleus; clonidine's alpha-2 agonism suppresses this noradrenergic hyperactivity, reducing sweating, anxiety, and GI distress.

A patient on methadone maintenance develops a prolonged QTc interval on ECG. Which factor most directly explains methadone's cardiac risk?

Answer: Methadone blocks cardiac hERG potassium channels, prolonging cardiac repolarization

Methadone blocks hERG (IKr) potassium channels responsible for cardiac repolarization, prolonging the QTc interval and increasing torsades de pointes risk.

Which of the following best explains the phenomenon of opioid-induced hyperalgesia (OIH)?

Answer: Chronic opioid exposure sensitizes NMDA receptors and reduces endogenous opioid production, paradoxically increasing pain sensitivity

OIH involves NMDA receptor sensitization and dynorphin-mediated mechanisms that increase pain sensitivity in patients on chronic opioids, distinct from tolerance.