Autocoids

Question 1

Histamine

Answer 1

Formed by decarboxylation of AA L-histidine
Immunologic release
Chemical and mechanical release
Drugs: morphone and tubocurarine

Found: lungs, skin, and GI
Released by mast cells and by type I hypersensitivity rxns with GPCRS

Question 2

Histamine receptors (4)

Answer 2

H1: Smooth muscle, endothelium, brain
H2: Gastric mucosa, cardiac muscle, mast cells
H3: Presynaptic autoreceptors
H4: Eosinophils, neutrophils

Question 3

H1 Activation

Answer 3

Hypotension: via NO (vasodilation)
Edema: Increase capillary permeability
Bronchospasm, increase pain and pruritis

Question 4

H1 receptors Antagonists: Indications

Answer 4

Allergic reactions
Nausea and vomiting
Sleep aids and cold meds

Question 5

H1 receptors Antagonists: Adverse Effects

Answer 5

Anticholinergics due to muscarinic blockade
Sedation
Except Loratadine, Cetirizine, Fexofenadine

Question 6

H1 receptors Antagonists Buzzword and Drugs

Answer 6

Sedation 
Diphenhydramine (OTC)
Promethazine (slight alpha blockade) 
Cholorpheniramine 
Meclizine (for motion sickness) 
Hydroxyzine 

No drowsiness nor sedation, doesn’t cross BBB
Loratadine, Cetirizine, Fexofenadine

Question 7

H2 Activation

Answer 7

Increase HCL secretion

Increase SA Nodal rate, increase contractility

Question 8

H2 Receptor Antagonists MOA

Answer 8

Block HCL secretion

Block secretory responses to food

Question 9

H2 Receptor Antagonists

Answer 9

Cimetidine
Famotidine
Ranitidine

Rx of indigestion, heart burn, duodenal ulcer, Zollinger-Ellison syndrome

Question 10

H2 Receptor Antagonists Adverse Effects:

Answer 10

1 - Cimetidine inhibits Cyp450 —> decrease metabolism of drugs and increased toxicity
theophylline, warfarin, phenytoin, diazepam

2 - Cimetidine decreases androgens: gynecomastia and decrease libido

3 - Famotidine: Blood dyscrasias (blood abnormality similar to thrombocytopenia, leukopenia, and agranulo cytosis

4 - Smoking decreases effects of H2 blockers

Question 11

Scopolamine

Answer 11

Anti-cholinergic indicated to prevent nausea and vomting, by blocking the Labyrinthine Vestibular system

Buzz word: Motion sicknexx
Side effects: dry mouth, urinary retention, constipation

Question 12

Serotonin (5HT) Receptor Drugs: Buspirone

Answer 12

5HT1A,

Rx of GAD

Question 13

Serotonin (5HT) Receptor Drugs: Sumatriptan

Answer 13

5HT1D

Migraine

Question 14

Serotonin (5HT) Receptor Drugs: Olanzapine

Answer 14

5HT2A

Antipsych

Question 15

Serotonin (5HT) Receptor Drugs: Cyprohepatadine

Answer 15

5HT2

H1-Blocker

Question 16

Serotonin (5HT) Receptor Drugs: *Ondansetron

Answer 16

5HT3
Antiemetic
*antagonist

Question 17

Serotonin (5HT) Receptor Drugs: Tegaserod

Answer 17

5HT4

IBD constipation

Question 18

Ergot Alkaloids: Ergotamine

Answer 18

Mixed partial agonist at 5 HT2 and alpha adrenoreceptor

Rx: Migraine and cluster headache

Question 19

Ergot Alkaloids: Ergonovine

Answer 19

mixed partial agonist at 5 HT2 and alpha adrenorecptor

Rx: Post partum bleeding and migraine headache

Question 20

Ergot Alkaloids: LSD

Answer 20

CNS 5 HT2 and dopamine agonist
5 HT2 antagonist in periphery
Not Used but widely abused

Question 21

Ondansetron

Answer 21

5HT3 Receptor antagonists (all “setrons:
Anti-emetic at CTZ (area postrema) and GI tract

Buzzword: nausea and vomiting due to cancer drugs

Question 22

Ondansetron: Adverse Effects:

Answer 22

Headache may occur with ondansetron

abdrominal cramps, dry mouth

Question 23

New Drug: Tegaserod

Answer 23

5-HT4 AGONIST

Question 24

New Drug: Tegaserod MOA

Answer 24

Activation of the 5HT4 receptors –> stimulates the peristaltic reflex

Question 25

New Drug: Tegaserod Buzzword

Answer 25

Irritable Bowel Syndrome for constipation in women