Pharm 2 Final Exam: CNS and Drugs of Abuse

Levodopa (L-Dopa)

MOA: Taken up by dopamine neurons and converted to dopamine. Use: Parkinson's disease. SE: Movement disorders from excess dopamine.

Haloperidol

MOA: Dopamine antagonist on postsynaptic receptors. Use: Schizophrenia/psychosis. SE: Extrapyramidal side effects (EPS).

Methylphenidate (Ritalin/Concerta)

MOA: Blocks dopamine and norepinephrine transporters, increasing synaptic levels of both. Ritalin = immediate release; Concerta = extended release. Use: ADHD. SE: Anxiety, irritability, insomnia, increased BP and HR.

Amphetamine (Adderall/Vyvanse)

MOA: Blocks dopamine and norepinephrine transporters; increases catecholamines packaged into vesicles. Vyvanse is a prodrug (D-amphetamine + lysine), limiting abuse potential. Use: ADHD. SE: Anxiety, irritability, insomnia, increased BP and HR.

Botulinum Toxin (botox)

MOA: Decreases release of acetylcholine at the neuromuscular junction, preventing muscle contraction. Use: Spasticity, overactive bladder, sialorrhea. SE: Effects of local injection last 3–6 months.

Fluoxetine (Prozac)

MOA: Serotonin reuptake inhibitor (SSRI). Use: Depression. SE: Fewer autonomic effects than TCAs.

Amitriptyline

MOA: Tricyclic antidepressant; blocks reuptake of serotonin and norepinephrine. Use: Anxiety/depression. SE: Sedation.

Diltiazem

MOA: Calcium channel blocker. Use: Hypertension. SE: N/A.

Methadone

MOA: Opioid agonist. Use: Long-term treatment for opioid use disorder or chronic pain. SE: Monitor QTc.

Disulfiram

MOA: Inhibits acetaldehyde dehydrogenase; causes buildup of acetaldehyde when alcohol is consumed, producing flushing, nausea, and vomiting. Use: Alcohol use disorder. SE: Patients may be non-adherent due to daily dosing.

Acamprosate

MOA: Modulates glutamate and GABA transmission to reduce alcohol cravings. Use: Alcohol use disorder. SE: Renally excreted; contraindicated in low GFR.

Naltrexone

MOA: Directly blocks opioid receptors, preventing euphoria; also used in alcohol dependence via opioid system role in reinforcement. Use: Alcohol use disorder / Opioid use disorder. SE: Hepatically metabolized; check LFTs before starting.

Buprenorphine

MOA: Partial opioid agonist. Use: Opioid use disorder. SE: Frequently combined with naloxone (Suboxone).

Bupropion (Wellbutrin)

MOA: Blocks reuptake of norepinephrine and dopamine. Use: Nicotine dependence; depression. SE: Lower sexual side effects than SSRIs/SNRIs; can be activating.

Varenicline (Chantix)

MOA: Partial agonist at α4β2 nicotinic acetylcholine receptors, mimicking nicotine's effects mildly. Use: Nicotine dependence. SE: Monitor for neuropsychiatric side effects.

Guanfacine

MOA: Alpha-2A adrenoreceptor agonist; decreases NE release presynaptically and increases prefrontal cortex connectivity postsynaptically. Use: ADHD. SE: Mild sedation; can help with insomnia due to reduced sympathetic tone.

Modafinil

MOA: Dopamine and NE reuptake inhibitor; histamine stimulator. Use: Narcolepsy (primary); ADHD (off-label). SE: N/A.

Ethanol (Drug of Abuse)

MOA: CNS depressant; potentiates GABA; inhibits ADH release. Use: N/A (drug of abuse). SE: Intoxication: euphoria, impaired attention. Withdrawal tx: Benzodiazepines.

Amphetamine (Drug of Abuse)

MOA: Increases synaptic NE and dopamine by increasing vesicular catecholamine packaging. SE: Euphoria, decreased fatigue, hypervigilance, paranoia. Intoxication tx: Lorazepam (agitation), Haldol (psychosis). Withdrawal tx: Supportive care.

Methamphetamine

MOA: Same as amphetamine; causes less NE release. SE: Same as amphetamine. Intoxication tx: Lorazepam, Haldol. Withdrawal tx: Supportive care.

MDMA (Ecstasy)

MOA: Increases dopamine and serotonin (psychostimulant + psychotomimetic). SE: Depersonalization, derealization, hallucinations. Tx: Supportive care.

Cocaine

MOA: Inhibits neuronal reuptake of NE and dopamine. SE: Euphoria, decreased fatigue, hypervigilance, paranoia. Intoxication tx: Lorazepam for agitation/seizures. Withdrawal tx: Supportive care.

Caffeine

MOA: Blocks adenosine receptors in CNS. SE: Decreased fatigue, increased concentration. Tx: Supportive care.

Nicotine

MOA: Activates nicotinic cholinergic receptors; inhibits MAO, activating dopaminergic pathways. SE: Tachycardia, increased concentration. Tx: Supportive care.

Marijuana (THC)

MOA: Binds cannabinoid receptors in neurons. SE: Mild stimulation then depressive stage; impaired short-term memory. Tx: Supportive care.

LSD

MOA: Selectively activates serotonin (5-HT) receptor subtypes in neocortex, limbic system, and brainstem. SE: Visual hallucinations, synesthesia. Tx: Supportive care.

PCP (Phencyclidine)

MOA: Dissociative anesthetic; blocks NMDA receptors. SE: Anxiety, delusions, emotional lability. Intoxication tx: Lorazepam (agitation), Haldol (psychosis). Withdrawal tx: Supportive care.

Benzodiazepines (Drug of Abuse)

MOA: Facilitates GABA activity. SE: Euphoria, impaired attention. Intoxication tx: Flumazenil for overdose. Withdrawal tx: Supportive care.