Histamine and Serotonin Antagonists

Question 1

Name the 5 1st generation H1 antagonists.

Answer 1

Diphenhydramine, tripelennamine, cyclizine, promethazine, chlorpheniramine

Question 2

Which of the 1st generation H1 antagonists in an ethanolamine with trade name Benadryl?

Answer 2

Diphenhydramine

Question 3

Which of the 1st generation H1 antagonists is an ethylenediamine derivative and OTC sleep aid?

Answer 3

Tripelennamine

Question 4

Which of the 1st generation H1 antagonists is a piperazine derivative and motion sickness medication?

Answer 4

Cyclizine

Question 5

Which of the 1st generation H1 antagonists is a phenothiazine derivative and an antiemetic?

Answer 5

Promethazine

Question 6

Which of the 1st generation H1 antagonists is an alkylamine derivative used in daytime cold medications?

Answer 6

Chlorpheniramine

Question 7

Of the 1st generation H1 antagonists, which 2 have the greatest anti-muscarinic and sedation effects? Which one causes the least sedation?

Answer 7

Diphenhydramine and promethazine; chlorpheniramine is least sedating

Note: tripelennamine is moderately sedating since it’s a sleep aid, but I guess that makes the sedation not a “side effect”

Question 8

Name the 4 2nd generation H1 antagonists

Answer 8

Loratadine, fexofenadine, azelastine, cetirizine

Question 9

What condition are the 2nd generation H1 antagonists all used to treat? Which antagonist can be given as an intranasal spray?

Answer 9

Allergic rhinitis; azelastine

Question 10

Which 2nd generation H1 antagonist is sold as an opthalmic solution to treat allergic conjunctivitis?

Answer 10

Azelastine

Question 11

Compared to the 1st generation H1 antagonists, what side effects and central effects do the 2nd generation H1 antagonists have? Why?

Answer 11

Less central and side effects, no sedation; because the 2nd gen drugs don’t cross the BBB

Question 12

Name the 2 piperidine derivatives. Are they 1st or 2nd generation H1 antagonists? What side effects are sometimes seen at high doses of these drugs?

Answer 12

Loratidine and fexofenadine; 2nd generation; cardiovascular effects (rare)

Question 13

Name the 4 H2 antagonists. What is their major effect in the body?

Answer 13

Cimetidine, ranitidine, famotidine, nizatidine; block gastric acid secretion

Question 14

List 3 conditions that H2 receptor antagonists are used to treat.

Answer 14

Dyspepsia, duodenal and gastric ulcers, hypersecretory conditions

Question 15

Which H2 antagonist has the most side effects? Which one has the least?

Answer 15

Cimetidine has the most; nizatidine has the least

Question 16

Which H2 antagonist can cause antiandrogen side effects like gynecomastia and impotence? Which one causes P450 inhibition? Liver toxicity? CNS dysfunction?

Answer 16

Cimetidine is anti-androgenic and P450-inhibitory; ranitidine is hepatotoxic; they can all cause CNS dysfunction

Question 17

Name the 3 non-ergot serotonin antagonists and the 1 class of non-ergot serotonin agonists

Answer 17

Cyproheptadine, ketanserin, odansetron; triptans

Question 18

In what kind of cells are 90% of the body’s serotonin / 5-HT receptors located?

Answer 18

In enterochromaffin cells of the GI tract

Question 19

What serotonin receptor antagonist is also an antihistamine? What 2 side effects can it cause as a result?

Answer 19

Cyproheptadine; can be anti-muscarinic and sedating (like diphenhydramine and promethazine)

Question 20

What 2 conditions is cyproheptadine used to treat, and which serotonin receptor is responsible for each of these effects?

Answer 20

Skin allergies (5HT1) and diarrhea of carcinoid syndrome (5HT2)

Question 21

What drug is an antagonist of 5HT2A, 5HT2C, α1 and H1 receptors? Give 2 therapeutic uses.

Answer 21

Ketanserin; anti-hypertension and anti-platelet aggregation

Question 22

What serotonin antagonist is used to treat nausea and vomiting in chemotherapy? What receptor does it target to achieve this effect?

Answer 22

Odansetron; 5HT3 receptor

Question 23

Name the non-ergot serotonin analogs that are agonists for the 5HT 1B and Dopamine receptors. What condition can they treat with 70% effectiveness?

Answer 23

Triptans; migraines

Question 24

Name the 4 ergot alkaloids

Answer 24

Ergotamine, methysergide, ergonovine, bromocriptine

Question 25

Which ergot alkaloid is a partial agonist at 5HT1, 5HT2, and all α receptors? What is it used to treat?

Answer 25

Ergotamine; migraines (prodrome)

Question 26

Which ergot alkaloid is a partial agonist at 5HT1 receptors and antagonist at 5HT2 receptors? What is it used to treat?

Answer 26

Methysergide; migraines (prophylaxis)

Question 27

Which ergot alkaloid acts on nonspecific uterine receptors, and what is it therefore used to treat?

Answer 27

Ergonovine; postpartum hemorrhage

Question 28

Which ergot alkaloid is a dopamine agonist, and what is it therefore used to treat?

Answer 28

Bromocriptine; hyperprolactinemia (and Parkinson's, although that's not in the chart)

Question 29

Name 2 common side effects of all the ergot alkaloids. Which ergot can also cause nausea, vomiting, and prolonged vasoconstriction in addition to these 2 effects?

Answer 29

Hallucinations and smooth muscle contraction; ergotamine can also cause the other problems

Question 30

Which ergot, which can cause GI distress and inflammatory fibrosis, has been withdrawn from the U.S. market because of its hallucinatory effects?

Answer 30

Methysergide