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Pharm 1 - Histamine & Serotonin

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drraythe's version from 2015-06-13 17:12

Histamine

Question Answer
What are the autocoids? (Basically means "local hormones")Histamine & Serotonin
Important Histamine receptors, & what they deal with?H1 (Inflammation, anaphylaxis, allergies/drug reactions) & H2 (gastric acid secretion, role in emesis)
Antihistiminergic drugs are acting against which receptor?H1
Major storehouse of Histamine is?Mast cell
Major effects of Histamine on CV, other?CV = vasodilation (capillary permeability ↑, so edema). Improves microcirculation & HYPOTENSION. Also dermal effects & gastric acid secretion & sm mm contraction
Which generation of antihistamines is responsible for producing sedative side effects? Why?Generation 1, bc not ionized at physiological PH so can permeate BBB
Side effects of antihistamines? (Gen 1)Sedation, at ↑ conc/chronic = excitation, drug tolerance, & CV dz (Arrythmias, hypertension)
What is the inhibitor of Histamine release from mast cells?Cromolyn sodium
What does Cromolyn sodium do? HOW does it do this?Inhibitor of Histamine release from mast cells - Opens Cl-channels → hyperpolarization of the cell membrane of mast cells
Is cromolyn sodium prophylactic or therapeutic?Prophylactic
What does Histamine do to (bronchial) sm mm?Contraction
H1 acts through what G protein?Gq to activate phospholipase C enzyme (you're one Qt (cute) & that's the usual)
H2 acts through what G protein?Gs to activate adenyl cyclase enzyme (Acid burnSSSSSSSSSS 2 much)
What is H3 concerned with?CNS neurotransmission
In which species does Histamine act as a vasopressor agent (vasoconstrict instead of dilate)RABBITS (lol, theyre ↑ strung)
In what species does Histamine RELAX smooth mm of the bronchi? (Usually constricts)CATS & SHEEP (why cats are fine w/ cat nip & sheep never has hay fever asthma from being in the field)
Summary of Histamine fxnVasodilation (relaxes arterioles) → improves microcirculation, hypotension. ↑ capillary permeability to edema. Sm mm contraction, stim sensory neurons (burning sensation, itching, pain). In CNS acts as important NT for MEDIATING EMESIS
Why do antihistiminergics incld antiemetic effects?Bc the Histamine can act as a NT in the CNS to mediate emesis
1st generation antihistiminergicsChlorpheniramine
Diphenhydramine
Clemastine
Hydroxyzine
Dimenhydrinate
Meclizine
Promethazine
Cyproheptadine
1st gen antihistamines have anti ___ propertiesAntimuscarinic
2nd gen antihistamines areCetirizine
Fexofenadine
Loratadine
Terfenadine
Astemizole
Pharm effects of AntihistaminesRelax bronchiole/intestinal sm mm. inhibits capillary permeability (so no edema) blocks neuronal reaction, so releases local anesthetic to relieve itching/burning/pain sensation & blocks vasodilation, & anti-emetic
Antihistamines used to Tx what two main thingsAllergy & inflammatory stuff
Are antihistamines antiadrenergic?No, theyre antimuscarninc
Three main side effects of antihistaminesSedation, drug tolerance, & antimuscarinic
Antihistiminergic is blocking what?Usually H1
Contraindications of antihistamines? (esp chronic use)In heart diseases (dont use them) bc can lead to tachycardia, arrhythmia, hypertension, hyperthyroidism, no glaucoma, no urinary retention, intestinal atony (bc antimuscarininc)
Cromalyn sodium facilitates what?Cl- ion influx → Hyperpolarization
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Serotonin

Question Answer
Physiological sig of Serotonin in GIT? In terms of blood? Nervous system?Rapid ↑ in GI motility (prokinetics). In platelets improves pro-coagulation. Important NT for regulating normal mood & b/h.
Examples of important SSRIs?Sertraline, **Fluoxetine, **Paroxetine, Fluvoxamine (w/ SSRIs youre as happy as on OX in a field)
What can Fluoxetine & Paroxetine be used for?Treating b/h probs
What are the 7 Serotonin receptors & what do they act on?5-HT1, 5-HT5 -Gi (inhibit adenylyl cyclase enzyme). 5-HT2 -Gq (acts through phospholipase C enzyme). 5-HT3 –ligand gated ion channel. 5-HT4 , 5-HT6,5-HT7 -Gs (activation of adenylyl cyclase enzyme)
Which is the ligand gated 5-HT receptor?5-HT3 (three is special & just HAS to have a toy. lol)
Which receptors work on Gi?1 & 5 (5 & 1 are def inhibiting- One ran away & Five fights every attempt)
Which receptors work on Gq?2 (It rhymes! - & she's the weirdo)
Which receptors work on Gs?4, 6, 7 (Shit storm between 4, 6, & 7. NOT FIVE because he is inhibitory)
Serotonin affects are similar to ___ & areSimilar to Histamine, are vasodilation, contraction of sm mm, & ENHANCES GI MOTILITY
How does Serotonin affect GI motility?ENHANCES IT
What is Cisapride & what does it do/how does it work?SEROTONIN AGONIST GI prokinetic agents, Tx constipation (bc concentrate on lower GI)/megacolon in cats Agonist of 5-HT4 receptor (so proud they're full of shit)
What is Metoclopramide & what does it do/ how does it work?SEROTONIN AGONIST of 5-HT4receptor, GI prokinetic agents anti emetic, Tx gastric stasis, GI atony, paralytic ileus, reflux esophagitis (met had stomach issues)
What is Ergometrine (ergot alkaloids for a more vague category) & what does it do/ how does it work?Ergometrine (Agonist of 5-HT2receptor), to control postpartum haemorrhage, uterine contraction/involution (I’d wanna be trippin too if I had to push out a baby. metrine =uterus)
What is Buspirone & what does it do & how does it work?5-HT1agonist anti-anxiety (one ran away because of how anxious the world made him, w/ its buses & pressures)
Which two drugs work on the 5-HT4 receptor?Cisapride & Metoclopramide (GI ones)
What is Cyproheptadine used for? What does it act on?Appetite stim in cats. ANTAGONIST of 5-HT1
What is an appetite stim in cats?Cyproheptadine
5-HT4 deals withGIT (if agonist, prokinetics) (cows got 4 stomachs)
What is Ketanserin? What does it do?Serotonin ANTAGONIST. (of 5-HT2) TX GLAUCOMA (KETOACIDOSIS IN YOUR EYES WILL MAKE YOU BLIND LIKE GLAUCOMA)
What is Methysergide? What does it do?Serotonin ANTAGONIST. (Of 5-HT2) TX Carcinoid syndrome (tumors all over GI- which will actually product Serotonin. weird.) (Doing meth will give you weird tumors - carcinomas in fact)
What are Ondansetron, Granisetron? What do they do?Serotonin ANTAGONIST. ANTI EMETICS during CHEMOTHERAPY (grannies get chemo a lot...on-& more)
What are they Serotonin antagonists? (4)(1) Cyproheptadine
(2) Ketanserin
(3) Methysergide
(4) Ondansetron/Granisetron
What are Serotonin agonists? (4)Cisapride
Metoclopramine
Ergometrine
Buspirone
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