Parasympathomimetics

Question 1

3 problems with Ach as a drug

Answer 1

Ineffective orally because of quartenary structure
Effects fleeting b/c rapid hydrolysis
widespread effects upon injection b/c its nonspecific

Question 2

Bethanechol

Answer 2

Beta methyl carbachol
absorbed orally when given as large dose
used in post-partem or post op urinary retention
atony in GI tract

Question 3

Cevimeline from plant

Answer 3

used to correct dryness of mouth and URT

after head and neck irradiation & Sjogren’s syndrome to correct dryness

Question 4

muscarine

Answer 4

alkaloid from mushroom (amanita muscaria)

historically important

Question 5

pilocarpine

Answer 5

also from plant
miotic in glaucoma
partial agonist, less headache
relieves block of canal of Schlemm by constricting pupil of the eye to allow for increased outflow of aqueous humor

Question 6

What is the main type of glaucoma

Answer 6

wide angle

Question 7

Difference between wide angle and narrow angle glaucoma

Answer 7

wide angle: can’t be relieved by surgery; on drugs for lifetime
narrow angle: can be relived by surgery; use pilocarpine

Question 8

Drugs used for glaucoma

Answer 8

beta blockers, prostaglandins, PILOCARPINE

Question 9

Precautions to parasympathomimetics

Answer 9

Asthma and hyperthyroidism