CNS drugs (antiepileptics, anesthetics) — Flashcards

Flashcard 1: Teratogenic effects of Carbamazepine

Answer: Neural tube defects, craniofacial defects, fingernail hypoplasia, developmental delay, IUGR

Flashcard 2: What is the characteristic teratogenic effect associated with Phenytoin use during pregnancy?

Answer: Fetal hydantoin syndrome

Extra: Fetal hydantoin syndrome is characterized by: - Orofacial clefts (cleft lip/palate) - Microcephaly and mental retardation - Nail and digital hypoplasia - Cardiac defects

Flashcard 3: valproate

Answer: neural tube defects (inhibition of maternal folate absorption)

Flashcard 4: Mechanism and use of Levodopa?

Answer: Dopamine precursor used in Parkinson's disease

Extra: Mechanism: Crosses blood-brain barrier (BBB) and is converted to dopamine by dopa decarboxylase. Clinical Use: Parkinson's disease. Side effects: GI distress, nausea, arrhythmias, dyskinesia (on-dose), akinesia (wearing-off/between dose).

Flashcard 5: Mechanism of action of Carbidopa:

Answer: Peripheral Dopa Decarboxylase Inhibitor

Extra: Mechanisms: Inhibits peripheral conversion of L-Dopa to Dopamine. \n- Does NOT cross the Blood-Brain Barrier (BBB).\n- Used in combination with Levodopa to increase CNS bioavailability and reduce peripheral side effects (nausea/vomiting).

Flashcard 6: Mechanism of action and clinical use of Selegiline?

Answer: Irreversible MAO-B inhibitor (used in Parkinson's disease) \u001f\u001f\u001f

Extra: <b>Mechanism:</b> Selectively inhibits MAO-B, increasing dopamine levels in the brain.<br><b>Clinical Use:</b> Parkinson's disease (adjunct to Levodopa/Carbidopa).<br><b>Note:</b> Can enhance the adverse effects of levodopa (e.g., dyskinesias, hallucinations).

Flashcard 7: What is the mechanism and clinical use of Entacapone?

Answer: COMT inhibitor used in Parkinson's disease

Extra: Used to prevent peripheral L-dopa degradation (inhibits Catechol-O-methyltransferase). Unlike tolcapone, entacapone acts only peripherally and is not hepatotoxic.

Flashcard 8: What is the mechanism and clinical use of Tolcapone?

Answer: COMT inhibitor used in Parkinson's disease (acts both centrally and peripherally)

Extra: Mechanism: Inhibits Catechol-O-methyltransferase (COMT), preventing the degradation of peripheral L-Dopa to 3-O-methyldopa and central Dopamine to HVA. Note: Tolcapone is associated with hepatotoxicity (requires LFT monitoring), unlike Entacapone which lacks central action and significant liver toxicity.

Flashcard 9: What is the mechanism and clinical use of Benztropine?

Answer: Antimuscarinic (Centrally acting anticholinergic) used in Parkinson's disease and Drug-Induced Extrapyramidal Symptoms (DIEP)

Extra: Mechanism: Improves tremor and rigidity in Parkinson's; also helps with acute dystonia caused by antipsychotics. \u001f PARK it: Benztropine, Trihexyphenidyl (Atropine-like effects).

Flashcard 10: Mechanism of action and clinical use of Memantine?

Answer: NMDA receptor antagonist used in Alzheimer's disease

Extra: Mechanism: Non-competitive NMDA receptor antagonist; prevents glutamate-mediated excitotoxicity. Clinical Use: Moderate to severe Alzheimer's disease. Side Effects: Dizziness, confusion, hallucinations.