E2. Autacoids Flashcards
What are the 4 groups that are classified as autacoids?
- Histamine
- Serotonin (5‐HT)
- Prostaglandins (PGs)
- Peptides
Select the drugs that are serotonin (5 –HT) agonists?(can be more than one) A. Fluoxetine B. Ranitidine C. Ondansetron D. Cisapride E. Metoclopramide
D. Cisapride
A. Fluoxetine
C and E are antagonists
What does Cisapride act on (MOA), and what is its use?
– Mechanism of action
• 5‐HT4 receptor agonist in enteric neurons
– Use
• Prokinetic
How does Fluoxetine work?
Acts by increasing serotonin levels in the brain. Increasing those levels improves signs of depression in humans.
What is the clinical use for Fluoxetine?
-Approved for treatment of canine separation anxiety in conjunction with a behavior modification plan
• Used in dogs and cats to treat other behavioral disorders such as
aggression, obsessive compulsive behaviors and anxiety
• Used in treatment of cats with inappropriate elimination and urine marking
What are some side effects you will see from Fluoxetine use? (5)
Nausea, anorexia, anxiety, irritability, and sleeping disturbances. (More information look at page 267)
What drugs are serotonin (5 – HT) antagonist? (3)
Cyproheptadine, Onidasetron, Metroclopramide.
What is the mechanism of action for Cyproheptadine?(3)
- Blocks H1‐receptors
- Blocks serotonin receptors
- Inhibition of serotonin inhibits ACTH
What are the three uses for Cyproheptadine?
- Antihistamine
- To stimulate appetite in small animals
- In the treatment of “serotonin syndrome” in dogs and cats
What is the mechanism of action for Onidasetron and Metroclopramide?
Onidasetron:
• 5‐HT3 receptor antagonist (central and peripheral)
Metroclopramide:
• 5‐HT3 receptor antagonist
• D1 and D2 receptor antagonist
What are the clinical uses for Onidasetron and Metroclopramide?
Onidasetron:
• Prevention and treatment of anticancer chemotherapy‐ induced nausea and vomiting
Metroclopramide:
• Antiemetic
• Prokinetic
Look at the slides 1-3/6 for histamine information
.
What are the four drugs/groups that generally inhibit histamine release? (4/6)
– catecholamines (epinephrine)
– cromolyn sodium
– phosphodiesterases (aminophylline)
– glucocorticoids
When you inhibit H1 receptors you are blocking which of the following? A. Inflammation B. Anaphylaxis C. Allergies D. Drug reactions E. All of the above
E. All of the above
What are the H2 receptors required for?
Gastric acid secretion
What are the major H1 mediated effects? (4) (slide6-7/6)
- Contraction of smooth muscles (esp. GI, bronchioles, uterus and large vessels classically resulting in bronchoconstriction).
- Vasodilation and then contraction of small vessels – capillaries, arterioles and venules - which leads to increased permeability (shock, hypotension, edema).
- Positive inotropic effect.
- Other effects such as CNS stimulation/alterations in sleep/wake cycles, itching, vomiting and
inappetence, and local reflex vasodilation.
What is the major H2 mediated effect?
Gastric acid secretion
Look at slides 9 – 10/6. More important just to know that they are H3 and H4 receptors
.
What drugs are your H1 agonists (first generation)? (10)
Pyrilamine(Equiphed®)
Diphenydramine(Benadryl®),
Dimenhydrinate (Dramamine, Gravol®),
Chlorpheniramine(Chlor-trimetron®)
Of the 10 first-generation H1 blockers how many are primarily used for something else?
3
Which of these drugs are used as appetite stimulants in cats? A. Dimenhydrinate (Dramamine, Gravol®) B. Cyproheptadine(Periactin®) C. Meclizine(Antivert®) D. Any of the above can work E. None of the above work
B. Cyproheptadine(Periactin®)
Which of these drugs are used to treat vestibular nausea? A. Dimenhydrinate (Dramamine, Gravol®) B. Cyproheptadine(Periactin®) C. Meclizine(Antivert®) D. Any of the above can work E. None of the above work
A. Dimenhydrinate (Dramamine, Gravol®)
Which of these drugs are used to treat for "old dog" vestibular disease in canines? A. Dimenhydrinate (Dramamine, Gravol®) B. Cyproheptadine(Periactin®) C. Meclizine(Antivert®) D. Any of the above can work E. None of the above work
C. Meclizine(Antivert®)
What are the three drugs that are second-generation H1 blockers?
- Terfenadine (Seldane®)
- Loratadine (Claritin®)
- Fexofenadine (Allegra®)