Pharm Histamine, Serotonin, & The Ergot Alkaloids

Front 1

Question: The effects of serotonin from metastatic carcinoid tumor is most likely to involve?

Back 1

Serotonin causes bronchospasm. Carcinoid is associated with diarreha and hypertension.

Front 2

Question: In recommending treatment for a carcinoid PT, what drug is likely to help?

Back 2

Cyproheptadine, ketanserin, phenoxybenzamine

Front 3

Question: What drug is the most effective physiologic antagonist of histamine in smooth muscle?

Back 3

Epinephrine

Front 4

Question: A 20 year old woman is taking diphenhydramine for severe hay fever. What adverse effect is she most likely to report?

Back 4

Sedation.

Front 5

Question: What will follow the result from blockade of H2 receptors?

Back 5

H2 receptors are Gs protein coupled receptors, like beta receptors; therefore, blockade will cause a decreased cAMP in cardiac m.

Front 6

Question: What is a recognized effect of cimetidine?

Back 6

CYP450 inhibition.

Front 7

Question: What are possible pharmacologic explanations of 16th and 17th century accounts of witchcraft?

Back 7

Ingestion of bread made from spoiled grain caused painful burning sensations in the limbs (therefore supernatural evil forces); clusters of abortions; hallucinations and behaviors interpretable by others "casting spells".

Front 8

Question: A 40 year old PT is about to undergo cancer chemotherapy with a highly emetogenic drug combination. The antiemetic drug most likely to be included is?

Back 8

Ondansetron, a 5-HT3 antagonists.

Note: diphenhydramine and prednisone are also used for this purpose.

Front 9

Question: What is correct about H2 blockers?

Back 9

All H2 blockers have approximately equal efficacy.

Front 10

Question:

Alosetron is used for?

Ergonovine?

Ondansetron?

Cetirizine?

Back 10

IBS

Uterine bleeding

Chemotherapy-induced emesis

Hay fever

Front 11

Question: What is most effective in the treatment of hyperprolactinemia?

Back 11

Bromocriptine.

Front 12

Question: What is most effective in the treatment of peptic ulcer disease?

Back 12

Mainly PPI, but H2 blockers are appropriate treatment.

Front 13

Question: What is a serotonin agonist useful in aborting an acute migraine headache and is not derived from a fungus?

Back 13

Sumatriptan, an agonist of 5-HT1d

Note: the fungus would be ergotamine

Front 14

Question: What is the most useful antidote for reversing severe ergot-induced vasospasm?

Back 14

Nitroprusside.

Front 15

What are autacoids?

What 4 are included in this group?

Back 15

Endogenous substances that have potent nonautonomic effects when administered as drugs.

Histamine, serotonin, prostaglandins, vasoactive peptide.

Front 16

What is an ergot alkaloid?

Back 16

A group that interact with serotonin receptors, dopamine receptors, and alpha receptors.

Front 17

What is ergotism (St. Anthony's fire)?

Back 17

Disease caused by excess ingestion of ergot alkaloids, such as grains that is contaminated by the ergot fungus.

Front 18

What is histamine's metabolite?

Back 18

Imidazole acetic acid.

Front 19

What are the four histamine receptors, MOA, and location?

Back 19

H1: smooth m; Gq: increase IP3, DAG

H2: stomach, heart, mast cells; Gs: increase cAMP

H3: nerve endings, CNS; Gi: decrease cAMP

H4: leukocytes; Gi

Front 20

What two histamine receptors are involved in the small red spot at the center of an intradermal injection of histamine surrounded by a red edematous wheal?

Back 20

H1 and H2

Front 21

What does the H1 receptor cause?

Back 21

Pain, itching in the skin, bronchoconstriction. and vasodiltation, the later caused by release of nitric oxide.

Front 22

What does the H2 receptor cause?

Back 22

Gastric acid secretion by parietal cells.

Cardiac stimulant effect.

Reduce histamine release form mast cells--a negative feedback.

Front 23

What does the H3 receptor cause?

Back 23

Presynaptic modulation of histaminergic neurotransmission in the CNS.

Food intake and body weight increase H3 receptor knockout animals. In the periphery, modulatory effects on the release of other transmitters.

Front 24

What does the H4 receptor cause?

Back 24

Located on leukocytes (especially eosinophils) and mast cells.

Front 25

What first generation of H1 antagonist is highly sedating with significant autonomic receptor blocking effect?

What other first generation is less sedating and has much less autonomic effect?

Back 25

Diphenhydramine.

Chlorpheniramine and cyclizine.

Front 26

What 2nd generation of H1 blockers are far less lipid soluble than 1st generation and have reduced sedating and autonomic effects?

Back 26

Cetirizine, fexofenadine, loratadine.

Front 27

What are H1 blockers used for?

What one is primarily an antiemetic?

Used to treat vertigo?

Has more anti-motion sickness action but is more sedative and autonomic effects?

Management of chemotherapy induced vomiting?

Back 27

Allergies, motion sickness

Promethazine

Meclizine

Cyclizine

Diphenhydramine

Front 28

What are the SE of H1 blockers?

The SE is more common with what?

Back 28

Sedation and antimuscarinic effects.

Diphenhyydramine and promethazine.

Front 29

What are the H2 blockers, and what is the only application for their use?

PPI work better than these H2 blockers with what?

Back 29

Cimetidine. Ranitidine, famotidine, and nizatidine.

Their only therapeutic effect is reduction of gastric acid secretion, such as in acid-peptic disease forming duodenal ulcers.

They are not as effective as PPI in Zollinger-Ellison and with GERD.

Front 30

What are the SE of cimetidine?

Back 30

Potent inhibitor of CYP450 and significant antiandrogen.

Front 31

What is serotonin produced from? Where is it located? Its metabolite?

Back 31

Produced from tryptophan, stored in vesicles in the enterochromaffin cells of the gut and CNS and enteric nervous system.

5-hydroxyindole acetic acid (5-HIAA)

Front 32

What do 5-HT1 receptors do?

Back 32

Brain: mediate synaptic inhibition via increase K conduction.

Peripheral: mediate both excitatory and inhibitory effects in various smooth m.

Front 33

What do 5-HT2 receptors do?

What tumor pertains to this one?

Back 33

Synaptic excitation in the CNS and smooth m. contraction (gut, bronchi, uterus, vessels) or relaxation (other vessels).

Mediates vasodilation, diarrhea, and bronchoconstriction of carcinoid tumor.

Front 34

What do 5-HT3 receptors do?

Antagonists to this receptor is useful for?

Back 34

Chemoreceptive area and vomiting center in peripheral sensory and enteric nerves.

Useful as an antiemetic drug.

Front 35

What does 5-HT4 perform?

Back 35

Found in GI tract, role in intestinal motility.

Front 36

What is a 5-HT(1d) agonists? What is it used for?

SE?

Back 36

Summatriptin (also naratriptan, rizatriptan, zolmitriptan).

DOC for acute migraine and cluster headache.

They cause vasoconstrction and inhibition of trigeminal activation and vasoactive peptide release.

Coronary vasospasm that results in chest pain and dizziness. Therefore, contraindicated in PTs with coronary a. disease.

Front 37

What are the 3 5-HT2 blockers? What two are competitive pharmacological antagonists and which one is an irreversible blocker?

What 2 has alpha blocking affect?

Which one has H1-blocking effect?

Back 37

Ketanserin and cyproheptadine (competitive pharmacologic blocker)

Phenoxybenzamine (irreversible).

Ketanserin, phenoxybenzamine

Cyrproheptadine

Front 38

Which 5H2 antagonists can be used as a antihypertensive drug?

What two drugs can be used for carcinoid tumor?

Back 38

Antihypertensive drug.

Cyproheptadine and phenoxybenzamine.

Front 39

What are 5-HT3 blockers?

Back 39

Ondansetron, granisetron, dolasetron, alosetron

Front 40

Which 5-HT3 receptor blokers have important antiemetic actions in the area postreme of the medulla and on peripheral sensory and enteric nerves.

What drug is extremely useful in control of vomiting associated with cancer chemotherapy and postoperative vomiting?

Treatment of women with IBS associated with diarrhea.

Back 40

Ondansetron, granisetron, dolasetron.


Ondansetron

Alosetron

Front 41

What is the SE of ketanserin?

SE dolasetron?

Back 41

Alpha1 receptor blocker --> Hypotension.

QT prolongation

Front 42

Most ergot alkaloids have a partial agonist on?

Back 42

Alpha and 5-HT receptors.

Some are also agonist at dopamine receptors.

Front 43

What Ergot is the mainstay treatment of acute attacks of migraine and is still used in combination with caffeine?

What Ergot is used to reduce postpartum bleeding?

Back 43

Ergotamine

Ergonovine

Front 44

What ergot alkaloid can produce marked and prolonged alpha-receptor mediated vasoconstriciton that can cause ischemia and gangrene of the limbs? Also block the alpha-agonist of sympathomimetics?

What about induce contraction of the uterine to cause abortion.

Back 44

Ergotamine

Ergonovine

Front 45

What two ergot alkaloid are potent dopamine-like agonist and inhibit prolactin? What else are they used for?

Back 45

Bromocriptine and pergolide.

Reduce the size of prolactin secreting pituitary tumors. Both have been used for Parkinson's

Note: dopamine inhibits the release of prolactin.

Front 46

What are the vascular SE of ergot toxicity?

Back 46

ischemia and gangrene (antidote is nitroprusside).

Hyperplasia of CT (fibroplasia). Similar lesions can be found with carcinoid syndrome.