Histamine, Serotonin

Question 1

Describe autocoid transmission

Answer 1

local release and action of mediators like histamine, serotonin, prostaglandins, and leukotrienes

Question 2

Describe Neuropathic vs psychogenic pruitis

Answer 2

Neuropathic: autacoid group binding to receptor

Psychogenic: thinking about itching makes you itch

Question 3

Histamine is ________ stored & inactivated

Answer 3

rapidly

Question 4

What do histamine receptors in the stomach produce?

Answer 4

Hydrochloric acid

Question 5

What drugs induce histamine release?

Answer 5

Morphine
Tubocurarine

Question 6

_____ can induce histamine release

Answer 6

trauma

Question 7

Where are H1, H2, H3 receptors

Answer 7

H1 - blood vessels
H2 - stomach
H3 - brain

Question 8

List the major organ system effects of histamine and serotonin.

Answer 8

Histamine: CVS: vasodilation & increased permeability
Respiratory: bronchoconstriction
GI: stimulating gastric acid secretion

Serotonin: CNS: regulating mood, sleep, and appetite
CVS: vasoconstriction/dilation
GI: promoting peristalsis

Question 9

List the effects seen in the Triple Response of allergy testing and mediators.

Answer 9

** injecting small amounts of allergens to see what has a positive reaction**

Redness (due to capillary dilation)

Flare (a wider area of redness due to arteriolar dilation)

Wheal (a raised area due to increased vascular permeability) Mediators involved include histamine and other inflammatory substances

Itch

These are mediated by the release of histamine and other inflammatory mediators from mast cells.

Question 10

List H1 antagonist

Answer 10

1st generation: Benadryl, phenergan, dramamine (crosses BBB - sedative effects - can be used for nausea)

2nd: Claritin, allegra, zyrtec (no CNS effects)

Question 11

What drug counters histamine but not on the H-Receptors?

Answer 11

Epi

Question 12

List H2 antagonists

Answer 12

OTC antacids

-dine

Question 13

Children may have _______ effects with H1 antagonist

Answer 13

reverse

Question 14

T/F: Platelet degranulation releases serotonin

Answer 14

T

Question 15

Where is most of our serotonin stored?

Answer 15

90% stored in enterochromaffin cells in the gut

Question 16

Describe the pharmacology of the 2 groups of H1 antihistamines and list prototypical agents for each group

Answer 16

a. First generation (sedating): Cross blood-brain barrier, have anticholinergic effects.

i. Prototypes include diphenhydramine (Benadryl) and chlorpheniramine.

b. Second generation (non-sedating): Do not cross blood-brain barrier as readily, fewer anticholinergic effects.

i. Prototypes include cetirizine (Zyrtec) and loratadine (Claritin).

Question 17

Where is serotonin produced in the brain?

Answer 17

raphe nuclei

Question 18

Serotonin is a derative of _________. and _____________ is a derative of serotonin

Answer 18

tryptophan

melatonin

Question 19

What does increase in 5-HIAA in stool indicate?

Answer 19

tumor that is overproducing 5-HT vs infection causing diarrhea

Question 20

List the uses of the H2 antihistamines, contrast PPIs, and name 2 members of this group.

Answer 20

H2 antihistamines reduce gastric acid secretion in conditions like peptic ulcers and gastroesophageal reflux disease (GERD).

PPIs: Proton pump inhibitors (PPIs), (e.g. omeprazole) are more effective at reducing gastric acid secretion and have a longer duration of action compared to H2 antihistamines.

Question 21

Describe serotonin effects in neural and non-neural tissues.

Answer 21

a. Neural: In the brain, serotonin regulates mood, anxiety, and sleep

i. Appetite, pain, itch can also be affected

b. Non-neural: Platelet aggregation, vasoconstriction, gastrointestinal motility

i. Remember, SERO (Serum) TONIN (tone) so vessel tone is how it received its name originally

Question 22

Describe the serotonin receptors

Answer 22

5-HT 1-7

All are GPCRs except 5-HT3 which is an ion channel

Question 23

What Serotonin receptor is associated with nausea? where is it located?

Answer 23

5-HT3

postrema in the brain

Question 24

List the source of serotonin in the brain, three main 5-HT agonist targets, two main 5-HT antagonist targets, and drugs in each category.

Answer 24

a. Serotonin in the brain is primarily produced in the raphe nuclei.

b. Main 5-HT agonist targets:
i. 5-HT1A e.g. buspirone (anxiety)
ii. 5-HT1B/1D e.g. sumatriptan (migraine)
iii. 5-HT2 e.g. Phenoxybenzamine (platelet aggregation, smooth muscle)

c. Main 5-HT antagonist targets:
i. 5-HT3 e.g. ondansetron (nausea/vomiting)

Question 25

Compare and contrast preventatives and treatments for migraine headache

Answer 25

Preventatives: beta blockers, CCB, antidepressants, anti-seizure medications, and CGRP monoclonal antibodies, glucocorticoids (prednisone), botox Tx: Triptans (sumatriptan), NSAIDs (ibuprofen), ergots (ergotamine and dihydroergotamine), and antiemetics (metoclopramide)

Question 26

Describe the action and indication for the use of sumatriptan.

Answer 26

5-HT1B/1D agonist used migraines vasoconstriction of cranial blood vessels and block pain signaling to treat the headache and associated symptoms.

Question 27

what neurotransmitters are associated with migraines?

Answer 27

CGRP Substance P Trigeminal nerves

Question 28

What effect does St. John warts have on serotonin levels?

Answer 28

increases them

Question 29

List the three categories of hyperthermia disorders, contributing factors, and treatments.

Answer 29

Serotonin Syndrome: triggered by serotonergic medications = SSRIs, MAOIs, and certain recreational drugs; serotonin excess -Tx: Benzodiazepine, paralyze, intubate Neuroleptic Malignant Syndrome: associated with antipsychotic medications, particularly those that block dopamine receptors. Tx: Diphenhydramine IV, cooling Malignant Hyperthermia: triggered by certain anesthetic agents, such as succinylcholine and volatile anesthetics Tx: Dantrolene, cooling

Question 30

dopamine is a derivative of ________

Answer 30

tyrosine

Question 31

Describe the Dopamine receptors

Answer 31

D1-5 Located all over body All metabotropic D1 is postsynaptic D2-5 are autoreceptors and postsynaptic

Question 32

Recall the dopamine mesolimbic pathway for reinforcement of behaviors. Vs Nigrostriatal and Mesocortical

Answer 32

pathway associated with reinforcement and reward in the brain Plays a role in addiction/negative and positive reinforcement of behaviors Nigrostriatal- movement Mesocortical- memory/planning

Question 33

Depression is ______ energy; anxiety is ________

Answer 33

lack of energy excess of energy/worrying

Question 34

Differentiate between anxiety and depression, and list major types of each.

Answer 34

Depression: dysthmia, psychosis, postpartum, seasonal, bipolar Anxiety: generalized, obsessive- compulsive, PTSD, Social phobia

Question 35

List the four categories of antidepressant medications in order of treatment severity.

Answer 35

Selective serotonin reuptake inhibitors (SSRIs) Serotonin-norepinephrine reuptake inhibitors (SNRIs) Tricyclic antidepressants (TCAs) Monoamine oxidase inhibitors (MAOIs)

Question 36

List SSRI

Answer 36

**Inhibit SERT** (Serotonin transporter) Fluoxetine (Prozac) Sertraline (Zoloft)

Question 37

List SNRI

Answer 37

**Inhibit SERT and NET** (Serotonin&NE transporter) Cymbalta Pristique

Question 38

List Tricyclic Antidepressants

Answer 38

**inhibit SERT, NET, and anticholinergic effects** Elavil

Question 39

List Monoamine oxidase inhibitors

Answer 39

MAOIs **inhibit all transporters; rarely used** **LETHAL DRUG INTERACTIONS** Nardil - irreversible Selegiline

Question 40

List alternative therapies for depression.

Answer 40

-psychotherapy -lifestyle changes -electroconvulsive therapy -light therapy for seasonal affective disorder -herbal supplements: St. John's Wort.

Question 41

What is the major black box warning on all antidepressant?

Answer 41

Can cause suicidal ideation within the first 1-2 months of taking, especially in adolescence