Histamine and Serotonin Flashcards
Name the 5 H1 receptor antagonists.
- Diphenhydramine
- Tripelennamine
- Cyclizine
- Promethazine
- Chlorpheniramine
What are the general properties of the 1st generation H1 receptor antagonists?
rapidly absorbed, widely distributed, rapidly metabolized, OTC, many actions outside of H1 receptor antagonism
What are the clinical uses for H1 receptor anatagonists?
Allergic reactions, motion sickness, nausea and vomiting in pregnancy, sleep aids
What is Tripelennamine primarily used for?
OTC sleep aid
What is Cyclizine primarily used for?
motion sickness
What is Promethazine primarily used for?
Anti-emetic
What is Chlorpheniramine usually a component of?
cold medications; less sedating than others so in day time medications
Which two H1 receptor antagonists exhibit anti-muscarinic effects and sedation?
diphenhydramine and promethazine
Name the 4 2nd generation H1 receptor antagonists.
Loratidine, fexofenadine, Azelastine and Certirizine
What can all 2nd generation H1 receptor antagonists be used to treat?
Allergic rhinitis
Which of the following is available as an intranasal spray or opthalmic solution to treat allergic rhinitis and allergic conjunctivitis respectively? Loratidine, fexofenadine, Azelastine and Certirizine
Azelastine
Do the 2nd generation H1 receptor antagonists produce sedation?
NO
Do the 2nd generation H1 receptor antagonists cross the BBB?
NO
Which of the 2nd generation H1 receptor antagonists can cause cardiovascular side effects at high doses?
loratidine and fexofenadine
Which type of drug are Cimetidine, Ranitidine, Famotidine and Nizatidine?
H2 receptor antagonist; blocks gastric acid secretion (primarily nocturnally)
What are the H2 receptor antagonists used to treat?
Dyspepsia, duodenal and gastric ulcers, hypersecretory conditions
Which of the H2 receptor anatagonists has the most side effects? the least?
most-Cimetidine
least-Nizatidine
Which of the following can cause anti-androgen effects and can inhibit P-450 oxidative enzymes? Cimetidine, Ranitidine, Famotidine or Nizatidine
Cimetidine
Which of the following can cause liver toxicity? Cimetidine, Ranitidine, Famotidine or Nizatidine
Ranitidine
Which of the following can cause CNS dysnfunction? Cimetidine, Ranitidine, Famotidine or Nizatidine
ALL
What is the mechanism of Cyproheptadine and what is it used to treat?
antihistaminic and antiserotinergic; skin allergies (anti-5HT1) and diarrhea of carcinoid system (anti-5HT2)
What are the side effects of cyproheptadine?
anti-muscarinic effects and sedation
What is the mechanism of Ketanserin and what is used to treat?
selective 5HT-2A, 2C antagonists and a1, H1 antagonist; antihypertensive and antiplatelet aggregation
What is the mechanism of Odansetron and what is used to treat?
5HT3 receptor antagonist; nausea and vomiting in chemo
As a class, what type of receptors do the Ergot Alkaloids effect and what side effects can they produce?
5HT and a-adrenergic; hallucinations and smooth muscle contraction (vascular and uterine)
Name the 4 ergot alkaloids.
Ergotamine, Methysergide, Ergonovine, and Bromocriptine
Which 3 receptors is ergotamine a partial agonist of and what is it used to treat?
5HT 1, 2 and a-adrenergic; prodrome of migraines
Which 2 receptors does methysergide interact with?
5HT1-partial agonist
5HT2- antagonist
What is ergonovine used to treat?
postpartum hemorrhage
Which receptor does Bromocriptine interact with and what is it used to treat?
dopamine agonst; hyperprolactinemia
What are triptans and which receptors do they interact with?
non ergot serotinin analogs; 5HT1B, D receptor agonist
What are triptans used to treat?
migraines
What are the side effects of ergotamine?
Nausea and vomitting, cumulative and prolonged vasoconstriction
What are the side effects of methysergide?
GI disturbances, inflammatory fibrosis (chronic use), hallucinations; withdrawn from market because of these
What are the effects of histamine on the lungs and through what receptor does it work?
bronchoconstriction; H1
What are the effects of histamine on vascular smooth muscle and through what receptor does it work?
post capillary venule dilation, terminal arteriole dilation and venoconstriction; H1
What are the effects of histamine on vascular endothelial cells and through what receptor does it work?
contraction and separation of endothelial cells; H1
What are the effects of histamine on the nervous system and through what receptor does it work?
sensitization of afferent nerve terminals causing pain and itching: H1
What are the effects of histamine on the heart and through what receptor does it work?
minor increase in HR and contractility; H2
What are the effects of histamine on the stomach and through what receptor does it work?
increases gastric acid secretion; H2
What are the effects of serotonin on the GI tract?
contraction of GI smooth muscle
What are the effects of serotonin on the cardiovascular system?
vasoconstriction of smooth muscle, vasodilator in skeletal muscle and heart, reflex bradycardia and platelet aggregation
What are the effects of serotonin on the nervous system?
sensitization of sensory receptors causing pain and itching