Pharmacology Exam 6

Card Set Information

Author:
Rx2013
ID:
79997
Filename:
Pharmacology Exam 6
Updated:
2011-04-16 13:40:40
Tags:
Histamine Antihistamine
Folders:

Description:
Histamine & Antihistamine
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user Rx2013 on FreezingBlue Flashcards. What would you like to do?


  1. Histamine
    • an amine chemical messenger
    • autocoid
  2. Histamine mediates a wide range of cellular responses including
    • allergic reactions
    • inflammatory reactions
    • gastric acid secretion
    • neurotransmissions in the brain
  3. Physiologic antagonist of histamine
    • epinephrine
    • does not act on the same receptor
  4. Histamine is synthesized in these cells
    • enterochromaffin-like cells
    • mucosal mast cells
    • neurons
  5. Histamine is synthesized from _____ by _____.
    • L-histadine
    • L-Histadine Decarboxylase
  6. Histamine is stored in ____ in _____
    • mast cells
    • granuels
  7. Storage granules in mast cells consist of
    inactive complex composed of histamine and polysulfated anion heparin with anionic proteins
  8. histamine is rapidly inactivated by_____ to _____.
    • monoamine oxidase type B
    • methylimidazole acetic acid
  9. Slowly turning over pool of histamine is found in ____ and ____.
    • mast cells
    • basophils
  10. Rapidly turning over pool of histamine is found in ____ and ____.
    • gastric ECL cells
    • histaminergic CNS neurons
  11. Extcretion of histamine
    • very little excreted unchanged
    • mostly metabolized by MAO B
  12. Neoplasms associaded with increased # of mast cells or basophils or with increased excretion of histamine and its metabolites
    • systemic mastycytosis
    • urticaria pigmentosa
    • gastric carcinoid
    • myelogenous leukemia
  13. Much lower concentrations of histamine are found in
    • ECL cells
    • neurons
  14. Location of histamine
    • practically all tissues
    • high amounts in lung, skin, GI tract
    • Brain
    • high concentrations in mast cells and basophils
  15. Ros of histamine in the CNS
    • pain transmission
    • arousal
    • hormone release
    • energy metabolism
    • sexual behavior
    • analgesia
  16. Histamine is a component of
    • venoms
    • insect stings
  17. Drugs that stimulate histamine release
    • reserpine
    • codeine
    • meperidine
    • morphine
    • D-tubocurarine
    • papaverine
    • Hydralazine
  18. Histamine release in the brain and other sites involves ______ . It is induced by ___ and dependent upon _____.
    • exocytosis
    • K+
    • Ca2+
  19. Histamine release from mast cells
    not released by K+ induced depolarization or by reserpine
  20. Other stimuli that release histamine from tissues
    • destruction of cells
    • cold
    • bacterial toxins
    • bee sting venoms
    • trauma
    • Allergies/anaphylaxis
  21. Diagnostic uses of histamine
    • pheochromocytoma (increases release of catecholamines)
    • bronchial hyper-reactivity
    • pernicious anemia (lack of acid release indicates achlorydia)
  22. Histamine exerts is effects bin binding these receptors
    • H1, H2, H3 and H4
    • all G-protein coupled receptors
  23. In the brain H1 and H2 are located
    post-synaptic
  24. In the brain H3 are located
    presynaptic
  25. H3 and H4 have ____% homology
    40%
  26. H1 receptors are present in these tissues
    • smooth muslce
    • endothelium
    • brain
  27. H1 Post receptor mechanism
    increase IP3 and DAG
  28. Partial H1 Agonist
    2-m-fluophenyl-histamine
  29. Partial H1 antagonist
    mepyramine
  30. H2 receptor tissue distribution
    • Gastric mucosa
    • cardiac mucle
    • mast cells
    • brain
  31. H2 Post receptor mechanism
    • stimulatory
    • increase cAMP
  32. Partial H2 agonist
    Impromidine
  33. Partial H2 Antagonist
    • Cimetidine
    • Ranitidine
  34. H3 tissue distribution
    • Presynaptic
    • brain
    • myenteric plexus
    • other neurons
  35. H3 Post receptor mechanism
    • inhibitory
    • decrease cAMP
  36. H3 partial agonist
    alpha-Methylhistamine
  37. H3 partial antagonist
    • thioperamide
    • clobenpropit
  38. H4 tissue distribution
    • eosinophils
    • neutrophils
  39. H4 post receptor mechanism
    • decrease cAMP
    • inhibitory
  40. H4 partial agonist
    • clozapine
    • clobenpropit
  41. H4 Partial antagonist
    thioperamide
  42. Gastric secretagogues
    • acetylcholine
    • histamine
    • gastrin
  43. Action of acetylcholine blocked by
    atropine
  44. Action of histamine blocked by
    • cimetidine
    • burimamide
    • metiamide
  45. Antagonist for gastrin
    no specific antagonist
  46. Histmaine action in the peripheral nervous system
    • capilary dialation and increased permeability
    • bronchoconstriction and GI contraction
    • stimulation of chromaffin cells
    • stimulation of sensory nerve endings causing pain
    • vasodilation, tachycardia, headache
    • stimulation of lung and gastric secretions
  47. H1 & H2 receptors in the cardiovascular system
    • lower peripheral resistance
    • positive chronotropism
    • positive inotropism
  48. Antihistamine mechanism of action
    • competitively block histamine receptors
    • do not affect formation or release of histamine
  49. Chromolyn Sodium
    degranulation of mast cells where histamine is stored
  50. 1st generation H1 receptor blockers
    • effective
    • inexpensive
    • high lipid solubility
    • significant anti-cholinergic effects
  51. 2nd generation H1 blockers
    • do not penetrate BBB
    • less CNS toxicity
  52. Ethanolamines
    • 1st generation
    • strong anti-cholinergic
    • available as injection
    • diphenhydramine
    • doxylamine
    • carbinoxamine
  53. Ethylamine diamines
    • 1st gen
    • mild anti-cholinergic
    • pyrilamine
    • tripelennamine
  54. Piperazines
    • 1st generation
    • no anti-cholinergic, injectable
    • cyclizine
    • meclizine
    • hydroxyzine
  55. Alkalamines
    • chlorpromazine
    • bromphenirmaine
    • mild-anticholinergic
    • injectable
    • 1st generation
  56. Phenothiazines
    • promethazine - strong anticholinergic
    • cyproheptadine - mild anticholinergic
    • injectable
    • 1st generation
  57. Piperidines
    • fexofenadine
    • loratadine
    • 2nd generation (non-sedating)
  58. Piperazines (2nd generation)
    • cetirizine
    • levocetirizine
  59. Alkylamines
    • 2nd generation
    • acrivastine
  60. Phthalazinones
    • azelastine
    • 2nd generation
    • nasal spray
  61. H1 blockers are useful in treating acute allergies cause by antigens actin on
    IgE antibody sensitized mast cells
  62. antihistamines are drug of choice in controlling symptoms of
    • allergic rhinitis
    • urticaria
  63. H1 receptor blockers are ineffective as monotherapy for
    • bronchial asthma
    • histamine is not the only cause
  64. H1 blockers used for motion sickness
    • diphenhydramine
    • meclizine
    • cyclizine
  65. Antihistamines diminish nausea and vomiting mediated by
    chemoreceptor and vestibular pathways
  66. Antiemetic action of antihistamines
    independant of antihistamine and other actions
  67. antihistamines used as somnifacients
    • diphenhydramine
    • doxylamine
    • may cause grogginess
  68. Pharmacokinetics of antihistamines
    • max serum levels w/in 1-2 hours
    • average t1/2 = 4-6 hours
    • majority of metabolism in the liver
    • metabolites excreted in the urine
  69. meclizine t1/2
    12-24 hours
  70. H1 receptor blockers (esp. 1st gen) may interact with
    • histamine receptors
    • muscarinic cholinergic receptors
    • alpha adrenergic receptors
    • serotonin receptors
  71. Adverse effects of antihistamines
    • sedation
    • dry mouth and nasal passages
  72. Drug interactions with antihistamines
    • potentiate effects of CNS depressants (alcohol)
    • MAOI can exacerbate anti-cholinergic effects
    • Erythromycin and clarithromycin interfere with metabolism of terfenadine and astemizole and may cause sever arrhythmias
  73. H1 recepor blockers do not interact with
    • dopamine receptors
    • beta adrenergic receptors
  74. Effective antidote for antihistamine poisoning that can reverse CNS excitement and convulsion
    diazepam
  75. Untreated antihistamine overdosage may result in
    • coma
    • respiratory collapse
  76. Major clinical use of H2 inhibitors
    inhibit gastric acid secretion for the treatment of ulcers
  77. 4 H2 blockers used in the US
    • cimetidine
    • ranitidine
    • famotidine
    • nizatidine
  78. H3 receptors are located
    • outside of the parietal cells
    • presyntaptically on cholinergic and noradrenergic noncholinergic neurons of the myenteric plexus where they inhibit release of neurotransmitters
  79. Potential applications of H3 agents have potential applications for
    • obesity
    • sleep disorders
    • psychiatric disorders
    • attention deficit disorders
  80. Tiprolisant
    • inverse H3 receptor agonist
    • decreases sleep cycles in narcolepsy
  81. H4 receptor blockers have potential use in
    • chronic inflammatory asthma
    • none avaiable for human use
  82. H1 selective blockers that show affinity for H4
    diphenhydramine

What would you like to do?

Home > Flashcards > Print Preview