Neurology: Pharmacology

Question 1

Epinephrine

Answer 1

alpha-agonist
glaucoma drug

mechanism: decreases aqueous humor synthesis via vasoconstriction

side effects: mydriasis; do not use in closed-angle glaucoma

Question 2

Brumonidine (alpha2)

Answer 2

alpha-agonist
glaucoma drug

mechanism: decreases aqueous humor synthesis

Side effects: Blurry vision, ocular hyperemia, foreign body sensation, ocular allergic reactions, ocular pruiritis

Question 3

Timolol, bextaxolol, carteolol

Answer 3

beta blockers
glaucoma drugs

mechanism: decreases aqueous humor synthesis

side effects: no pupillary or vision changes

Question 4

acetazolamide

Answer 4

diuretics

mechanism: decreases aqueous humor synthesis via inhibition of carbonic anhydrase

side effects: no pupillary or vision changes

Question 5

Direct cholinomimetics (pilocarpine, carbachol)

Answer 5

mechanism: increases outflow of aqueous humor via contraction of ciliary muscle and opening of trabecular meshwork

side effects: miosis and cyclospasm (contraction of ciliary muscle)

Question 6

Indirect (physostigmine, echothiophate)

Answer 6

mechanism: use pilocarpine in emergencies–very effective at opening meshwork into canal of Schlemm

Question 7

Latanoprost

Answer 7

prostaglandin
mechanism: increases outflow of aqueous humor

side effects: darkens color of iris

Question 8

Opioid analgesics

Answer 8

morphine, fentanyl, codeine, heroin, methadone, meperidine, dextromethorphan, diphenoxylate

mechanism: acts as agonists at opioid receptors to modulate synaptic transmission; inhibit release of ACh, NE, 5-HT, glutamate, substance P

clinical use: pain, cough suppression, diarrhea, acute pulmonary edema, maintenance programs for addicts

toxicity: addiction, respiratory depression, constipation, miosis, additive CNS depression with other drugs

Question 9

Butorphanol

Answer 9

mechanism: Mu-opioid receptor partial agonist and kappa-opioid receptor agonist; produces analgesia

clinical use: severe pain; causes less respiratory depression than full opioid agonists

toxicity: can cause opioid withdrawal symptoms if patient is also taking full opioid agonist

Question 10

Tramadol

Answer 10

mechanism: very weak opioid agonist; also inhibits serotonin and NE reuptake (works on multiple neurotransmitters–tram it all in with tramadol)

clinical use: chronic pain

toxicity: similar to opioids, decreases seizure threshold