Central Nervous System Agents Flashcards
7 cards from real Pharmacology practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Central Nervous System Agents flashcards as text
Which atypical antipsychotic has the highest risk of metabolic syndrome, including weight gain and diabetes?
Answer: Olanzapine
Olanzapine carries the highest risk of metabolic side effects among atypical antipsychotics, including significant weight gain, dyslipidemia, and new-onset diabetes.
A patient with absence seizures is started on ethosuximide. What is this drug's primary mechanism?
Answer: Blocking T-type voltage-gated calcium channels in thalamic neurons
Ethosuximide blocks T-type calcium channels in thalamic relay neurons, disrupting the 3-Hz spike-and-wave discharges characteristic of absence seizures.
A patient on chronic opioid therapy develops constipation unresponsive to laxatives. Which agent specifically targets this problem without reversing analgesia?
Answer: Methylnaltrexone subcutaneous
Methylnaltrexone is a peripherally acting mu-opioid receptor antagonist that relieves opioid-induced constipation without crossing the blood-brain barrier to reverse analgesia.
Which CNS drug class is most associated with causing anticholinergic toxidrome (dry mouth, urinary retention, tachycardia, confusion)?
Answer: Tricyclic antidepressants
Tricyclic antidepressants strongly block muscarinic receptors, causing classic anticholinergic effects including dry mouth, constipation, urinary retention, blurred vision, and confusion.
A patient taking phenytoin for seizures is prescribed warfarin. What drug interaction concern is most relevant?
Answer: Phenytoin increases warfarin metabolism by inducing CYP2C9
Phenytoin induces hepatic CYP2C9 enzymes, accelerating warfarin metabolism and reducing anticoagulant effect, requiring warfarin dose adjustment.
Which medication is a first-line treatment for acute migraine that works by selectively binding serotonin 5-HT1B/1D receptors?
Answer: Sumatriptan
Sumatriptan is a triptan that agonizes 5-HT1B/1D receptors, causing cerebral vasoconstriction and inhibiting trigeminal pain signaling to abort acute migraine attacks.
A patient with Alzheimer's disease is prescribed donepezil. What is this drug's primary mechanism of action?
Answer: Inhibits acetylcholinesterase to increase synaptic acetylcholine levels
Donepezil inhibits acetylcholinesterase, preventing acetylcholine breakdown and increasing cholinergic neurotransmission in brain regions critical for memory.