Neurology

Question 1

Glaucoma drugs that decrease aqueous humor synthesis

Answer 1

alpha-agonists (epinephrine, brimonidine) - causes mydriasis so do not use in closed-angle glaucoma; also causes visual changes

beta-blockers (timoloil, betaxolol, carteolol) - no pupillary or vision changes

carbonic anydrase inhibitors (acetazolamide) - no pupillary or vision changes

Question 2

Glaucoma drugs that increase aqueous humor outflow

Answer 2

direct cholinomimetics (pilocaropine, carbachol)

indirect cholinomimetics (physostigmine, echothiophate) - contract ciliary muscles and open trabecular meshwork; cause miosis; use pilocaropine in emergencies

prostaglandins (latanoprost) - brown color of iris

Question 3

Ethusuximide

Answer 3

First-line treatment of absence seizures.

Blocks thalamic T-type Ca channels.

Toxicities: GI distress, pruiritis, and Stevens-Johnson syndrome

Question 4

Treatment of absence seizures

Answer 4

Ethusuximide (first line), valproic acid, lamotrigine

Question 5

Treatment of status epilepticus

Answer 5

Benzos (acute tx) and Phenytoin (prophylactic tx)

Question 6

Phenytoin

Answer 6

First-line treatment of tonic-clonic seizures (along with carbamazepine and valproic acid). Also used as prophylactic tx for status epilepticus.

Increases Na channel inactivation.

Toxicity: Nystagmus, diplopia, ataxia, gingival hyperplasia, teratogenesis, SLE-like syndrome, induction of P-450, Stevens-Johnson syndrome, pseudo-lymphoma

Question 7

Carbamazepine

Answer 7

First-line treatment of simple, complex, and tonic-clonic seizures. Also functions as mood-stabilizer

Increases Na channel inactivation.

Toxicity: Diplopia, ataxia, bone marrow suppression, SIADH, teratogenesis, inducation of P-450, Stevens-Johnson syndrome

Question 8

Valproic acid

Answer 8

First-line treatment of tonic-clonic seizures (along with carbamazepine and phenytoin). Also used for absence seizures, myoclonic seizures, and bipolar disorder (functions as mood stabilizer)

Increases Na channel inactivation and increases GABA concentration by inhibition GABA transaminase.

Toxicity: Rare but fatal hepatotoxicity; spina bifida, weight gain

Question 9

Gabapentin

Answer 9

Treats simple, complex, and tonic-clonic seizures. Also used for peripheral neuropathy, postherapeutic neuralgia, migraine prophylaxis, and bipolar disorder.

Inhibits high-voltage-activated Ca channels; GABA analog.

Toxicity: sedation, ataxia

Question 10

Topriamate

Answer 10

Treats simple, complex, and tonic-clonic seizures. Also used for migraine prophylaxis.

Blocks Na channels, increases GABA action.

Toxicity: sedation, kidney stones, weight loss

Question 11

Lamotrigine

Answer 11

Treats simple, complex, tonic-clonic, and absence seizures. Also treats depressive phase of Bipolar disorder

Blocks voltage-gated Na channels.

Toxicity: Stevens-Johnson syndrome if titrated quickly

Question 12

Stevens-Johnson syndrome

Answer 12

Prodrome of malaise and fever followed by rapid onset of erythematous macules that progress to toxic epidermal necrolysis

Question 13

Order of nerve blockade of local anesthetics

Answer 13

Small myelinated fibers > small unmyelinated fibers > large myelinated fibers > large unmyelinated fibers.

Order of Loss: pain > temperature > touch > pressure

Question 14

Dantrolene

Answer 14

Treats malignant hyperthermia and neuroleptic malignant syndrome

Prevents the release of Ca from the SR of skeletal muscle

Question 15

Bromocriptine, Pergolide (ergot),

Pramipexole, Ropinirole (non-ergot)

Answer 15

Dopamine agonists used to treat Parkinson disease.

Ergots (bromocriptine) are preferred

Question 16

L-dopa/carbidopa

Answer 16

Increase dopamine levels in the brain to treat Parkinson disease.

Unlike dopamine, L-dopa can cross the BBB and is converted to dopamine by dopa decarboxylase in the CNS.

Carbidopa (peripheral decarboxylase inhibitor) increases the bioavailability of L-dopa in the brain

Question 17

Amantadine

Answer 17

Increase dopamine levels in the brain to treat Parkinson disease. Also used to treat influenza A and rubella.

Toxicity is ataxia.

Question 18

Selegiline

Answer 18

Prevents dopamine breakdown to treat Parkinson disease.

Inhibits MAO-B, which preferentially metabolizes dopamine over norepinephrine and 5-HT.

Used as an adjunctive treatment to L-dopa

Question 19

Entacapone, tolcapone

Answer 19

Prevents dopamine breakdown to treat Parkinson disease. Inhibits COMT.

Question 20

Benztropine

Answer 20

Antimuscarinic that treats tremor and rigidity in Parkinson disease. Little effect on bradykinesia.

Question 21

Memantine

Answer 21

NMDA receptor antagonist that treats Alzheimer disease.

Toxicity: dizziness, confusion, hallucinations

Question 22

Donepezil, galantamine, rivastigmine

Answer 22

AChE inhbitors that treat Alzheimer disease.

Question 23

Treatment of Huntington disease

Answer 23

Tetrabenazine and reserpine - inhibit vesicular monoamine transporter (VMAT) to limit dopamine packaging and release

Haloperidol - dopamine receptor antagonist

Question 24

Sumatriptan

Answer 24

Treatment of acute migraines and cluster headaches. 5-HT1b agonist that inhibits trigeminal nerve activation, prevents vasoactive peptide release, and induces vasoconstriction or cranial and basilar arteries.

Contraindicated with CAD or Prinzmetal angina due to risk of coronary vasospasm.

Question 25

Extra-CNS effects of inhaled anesthetics

Answer 25

Myocardial depression

Respiratory depression (except nitrous oxide)

Depression of mucociliary clearance (may predispose to postop atelectasis). Halothane and sevoflurane have bronchodilation properties (use in patients with asthma)

Increase cerebral blood flow and ICP (due to decreased vascular resistance in the brain)

Decrease GFR

Decrease hepatic blood flow

Question 26

Primidone

Answer 26

Anti-epileptic, metabolized to phenobarbitol (causes lethargy)