Preop Medication/Antiemetics 2-3 Flashcards
Test 1
Histamine is endogenous. What does this mean?
It is in our body all the time
What is histamine released from?
Basophils
Mast cells
What does histamine induce?
smooth muscle contraction in airways
-secretion of acid in stomach
-release of neurotransmitters in CNS (Acetylcholine, NE, Serotonin)
What are we worried about with endogenous histamine release?
Bronchospasms
-painful aspiration
Which drugs induce histamine release?
Morphine
Mivacurium (Mivacron)
Atracurium (Tracrium)
Protamine
How do we treat drug induced histamine released?
Both H1 & H2 antagonist
Have to give both
What receptors does histamine receptors H1 & H2 activate?
H1: Muscarinic, cholinergic, 5-HT3, Alpha-adrengic
H2: 5-HT3, B-1
What drug do we give in the OR almost everytime we give heparin?
Protamine
Which generation of drugs typically block the histamine cascade reaction?
1st generation antihistamine drugs such as benadryl
What are the presentations that you’ll see from histamine release from the H1 & H2 receptors?
H1: Hyperalgesia; inflammatory pain
H2: Increases cAMP (B1 stimulation –> inreases HR); increases acid/volume production
Both: Hypotension, capillary permeability, flushing, prostacyclin release
How does histamine release cause hypotension?
H1&H2 activation causes hypotension from release of nitric oxide & capillary permeability
Histamine receptor antagonist are actually _______ agonists
inverse
T/F: Histamine receptor antagonist prevent the release of histamine
F
Responds to the release of histamine
Where are H1 receptors located?
Vestibular system
airway smooth muscle
cardiac endothelial cells
What types of patients should we be cautious with H1 receptor antagonist? Why?
Ambulatory
elderly
Crosses BBB & makes you sleepy –> can fall more easily
Beside histamine induced reactions, what is another H1 receptor antagonist indication?
Motion sickness
H1 receptor antagonist should provide protections against _______ & ________ stability
brochospams
cardiac
H1-R antagonists has _______ tachyphylaxis? What does this mean?
little
should not decline in effectiveness with doses.
What are SE of H1-R antagonists?
Blurred vision
Urinary retention
Dry mouth
Drowsiness (1st gen)
BUDD
What are 2 1st gen H1-R antagonists?
- Diphenhydramine (benadryl)
- Promethazine (phenergen)
What are 2 2nd gen H1-R antagonist?
- Cetirizine (Zyrtec)
- Loratadine (Claratin)
What are general benefits of H1-R antagonists?
Cheap & effective
Benedryl is a ____ receptor ______
H1
antagonist
What is diphenhydramine (benadryl) mostly used for?
-antipruritic (itching)
-pre-treat procedure related allergies (ex. contrast)
-anaphylaxis/allergic reaction