Autacoids - DMARDS, NSAID, Gout Drugs Flashcards
Two most important amine autacoids
Histamine and Serotonin
Refers to endogenous molecules with powerful pharmacologic effects that do not fall into traditional autonomic groups
Autacoids
Histamine is formed from what amino acid?
Histidine
Enzymes that metabolizes the histamine
Monoamine oxidase and diamine oxidase
Triple response effect of histamine
Wheal, flush and flare
H1-receptor antagonists (1st generation): used for hay fever, angioedema, motion sickness, insomnia and dystonia. With drowsiness as sideeffect
Diphenhydramine - competitive block of peripheral and CNS H1 receptor
H1-receptor antagonist-2nd gen: used for urticaria, hay fever and angioedema. With no autonomic or anti-motion sickness effects
Cetirizine
H2-receptor antagonist used for peptic ulcer disease and Zollinger - Ellison syndrome and GERD. CYP450 inhibitor
Cimetidine - block H2 receptor, reduction of gastric acid secretion. Cimetidine has antiandrogen effect like gynecomastia
Serotonin is produced from what amino acid?
Tryptophan
Serotonin is metabolized by
Monoamine oxidase
Excess serotonin in the body is detected by ___ in the urine.
5-hydroxyindole acetic acid (5-HIAA)
5-HT receptor agonist: drug of choice for acute migraine, cluster headache. SE: paresthesias and dizziness
Sumatriptan - causes vasoconstriction hence modulates neurotransmitter release
5-HT3-receptor antagonist used for chemotherapy and postoperative vomiting. SE: diarrhea, headache
Ondansetron - blocks chemoreceptor trigger zone and enteric nervous system
Area distribution block by Ondansetron
Area postrema
Responsible for the St. Anthony’s fire described during middle ages
Ergot alkaloids - produced by a fungus found in wet or spoiled grain
5-HT2 vasoselective receptor antagonist used in migraine and cluster headache
Ergotamine - agonist causes marked smooth muscle contraction but blocks a-agonist vasoconstriction
Antidote used for Ergotamine
Nitroprusside
5-HT uteroselective antagonist used for postpartum bleeding and migraine. SE: IG upset, uterine spasm and abortion
Ergonovine
Refers to important group of endogenous fatty acid derivatives that are produced from arachnoid acid
Eicosanoids
Eicosanoids: bronchoconstriction, slow-reacting substance of anaphylaxis
LTC4 and LTD4