Autacoids

Question 1

what drugs can displace histamine from the heparin-protein complex within cells

Answer 1

morphine and tubocurarine

Question 2

H1 and H2 – who has the higher affinity for histamine and its significance

Answer 2

H1 – rapid response but short lived

H2 – slowly develops response but sustained

Question 3

what does activation of H1 and H2 lead to

Answer 3

H1 – works on endothelial cells so leads to production of NO
H2 - works on vascular SM so leads to vasodilation, in heart leads to increased contractility

Question 4

histamine agonist and its clinical use

Answer 4

histamine

pulmonary function testing (test nonspecific bronchial hyperactivity)

Question 5

toxicity of histamine

Answer 5

flushing, hypotension, tachycardia, headache, wheals (area of skin that is raised and itchy), GI upset, bronchial constriction

Question 6

who do you not give histamine to

Answer 6

asthmatics, those with acute ulcer disease, GI bleeding

Question 7

physiological antagonist of histamine

Answer 7

epinephrine

Question 8

release inhibitors of histamine

Answer 8

cromolyn and nedocromil (use to treat asthma)

beta 2 agonists as well

Question 9

what are the first generation H1 receptor antagonist

Answer 9

chlorpheniramine, cyclizine, dimenhydrinate, diphenhydramine, meclizine, promethazine, hydroxyzine

CD2 MPH

Question 10

what are the second generation H1 receptor antagonist

Answer 10

cetirizine, fexofenadine, loratadine, astemizole, terfenadine

C-FLAT

Question 11

why were astemizole and terfenadine removed from US market

Answer 11

induced potentially fatal arrhythmias called torsades de pointes

this occurred especially in the presence of CYP3A4 inhibitors leaving these two drugs in circulation longer than they are supposed to be

Question 12

actions of H1 receptor antagonist

Answer 12

• inverse agonist
• blocks histamine induced contraction of GI and bronchial
• bind to cholinergic, alpha adrenergic, serotonin, and local anesthetic receptor sites

Question 13

what are H1 receptor antagonists used for

Answer 13

• allergies caused by antigens acting on IgE antibody sensitized mast cells so like allergic rhinitis and urticaria
• not good at treating bronchial asthma because histamine is only one of the several mediators
• motion sickness and nausea (with scopolamine)
• insomnia

Question 14

which antihistamine is used as a somnifacients aka tx for insomnia

Answer 14

diphenhydramine

Question 15

which antihistamine is used as a tx for motion sickness and nausea

Answer 15

diphenhydramine, dimenhydrinate, promethazine

Question 16

adverse reaction of H1 blocker

Answer 16

sedation and dry mouth

Question 17

why is driving and operating heavy machinery cautioned against in H1 blockers

Answer 17

some H1 blockers cause sedation especially if taken with drugs that cause CNS depression

Question 18

adverse effects if overdosed on H1 blockers

Answer 18

hallucinations, excitement, ataxia, and convulsion

Question 19

what are H2 receptor antagonists

Answer 19

Famotidine, Ranitidine, Nizatidne, Cimetidine

FRaNC

Question 20

clinical use of H2 receptor antagonist

Answer 20

inhibit gastric acid secretion (induced by histamine or gastrin)
so used for the treatment of peptic ulcer, acute stress ulcers, GERD

Question 21

adverse effects of H2 blocker (we’ll talk about cimetidine in a diff flash card)

Answer 21

headache, diarrhea, muscular pain, constipation

• mental status changes
• blood dyscriasis
• bradycardia and hypertension

Question 22

adverse effects of cimetidine an H2 blocker

Answer 22

• inhibits CYP450 and slows metabolism of certain drugs

- binds to androgen receptors and has antiandrogenic effects like gynecomastia in men and galactorrhea in women

Question 23

what are the serotonin agonists

Answer 23

serotonin, sumatriptan, metoclopramide, cisapride

Question 24

what is sumatripan used to treat

Answer 24

migraine headache (first line therapy for acute migraine)

Question 25

who do you not prescribe sumatripan to and why

Answer 25

person with coronary heart disease because of their vasoconstrictive action

Question 26

what is metoclopramide given for

Answer 26

prokinetic agent - enhance GI motility by coordinating contractions that enhance transit

Question 27

adverse effects of metoclopramide

Answer 27

somnolence, nervousness, dystonic reactions

extrapyramidal effects and tardive dyskinesia

Question 28

use of cisapride

Answer 28

prokinetic agent - enhance GI motility for pts with gastroesophageal reflux and gastroparesis

Question 29

why is cisapride no longer widely used in US

Answer 29

because of its cardiac effects

Question 30

what is the serotonin 5-HT2 antagonist

Answer 30

cyproheptadine

Question 31

action of cyproheptadine

Answer 31

prevents smooth muscle effects of serotonin and histamine

Question 32

uses of cyproheptadine

Answer 32

perennial and seasonal allergic rhinitis
vasomotor rhinitis
allergic conjuctivitis due to inhalant allergens and foods
cold urticaria
dermatographism
serotonin syndrome (hyperthermia, muscle rigidity, and myoclonus)

Question 33

what is the serotonin 5-HT3 antagonist

Answer 33

ondansetron

Question 34

use of ondansetron

Answer 34

nausea and vomiting that occurs with cancer chemotherapy

Question 35

what are the ergoid alkaloids (also serotonin antagonist)

Answer 35

MEED CB

methylergonovine, ergonovine, ergotamine, dihydroergotamine, cabergoline, bromocriptine

Question 36

ergoid alkaloid used to treat migraine

Answer 36

ergotamine

Question 37

ergoid alkaloid used for hyperprolactinemia

Answer 37

bromocriptine and cabergoline

Question 38

ergoid alkaloid used for postpartum hemorrhage

Answer 38

ergonovine and methylergonovine

Question 39

what is used to diagnose variant angina (also do you remember what type of drugs you don’t use on pt with variant angina)

Answer 39

ergonovine to diagnose

do not use beta blockers on variant angina!