Pharm Chem Exam 1 Part 4

Home > Preview

The flashcards below were created by user crmozingo on FreezingBlue Flashcards.

  1. Histamine
    histamine is synthesized from the essential AA histidine through histidine decarboxylase
  2. Histamine (HA) receptor subtypes
    H1: mast cells store histamine in granules as heparin salts (sulfate)

    H2: enterochromafffin-like cells of gastric mucosa; activate protein pump which secretes HCl
  3. First generation antihistamines: H1-receptor antagonists
    see pharmacophore on page 33
  4. Diphenhydramine (NyQuil, Robitussin)
    • 1G antihistamine: H1 receptor antagonist
    • X=O
    • enthanolamine antihistamine
    • salt version: Benadryl (diphenhydramine chlorotheophyllinate) decreases drowsiness due to the stimulant effect of theophylline
    • chloro group of benadryl increases acidity salt and favors the salt conformation
  5. Pyrilamine (Midol)
    • 1G H1-receptor antagonists
    • X=N
    • ethylenediamine antihistamine
    • less anticholinergic SEs which can induce cough
  6. Chlorpheniramine
    • 1G H1-receptor antagonists
    • X=C
    • alkylamine antihistamine
    • reduced drowsiness
    • FYI: other examples: dimetapp, acetifed
  7. Hydroxyzine (Vistaril)
    • 1G H1-receptor antagonists
    • piperazine antihistamine
  8. Promethazine (Phenergan)
    • 1G H1-receptor antagonists
    • phenothiazine antihistamine
    • 10% as antidopaminergic as chlorpromazine
    • Tx: allegic rhinitis, N&V, muscarinic antagonist
  9. 2G H1-receptor antagonists
    • non-sedating
    • highly polar preventing penetration of BBB
  10. Terfenadine (Seldane)
    • 2G H1-receptor antagonists
    • victim drug
    • oxidized by 3A4 (DDIs!!!!!)
    • perpertrator drug
  11. Fexofenadine (Allegra)
    • 2G H1-receptor antagonists
    • %F unknown
    • fecal elimination
    • good Pgp substrate
    • no known DDIs
  12. Loratadine (Claritin)
    • 2G H1-receptor antagonist
    • shorter half life than parent drug desloratadine
    • metabolized by 2D6 and 3A4 DDIs: carbamate --- amine
    • went from Rx to OTC
  13. Desloratadine (Clarinex)
    • 2G H1-receptor antagonist
    • long half life
    • no 3A4 DDI or 2D6 polymorphism
    • premetabolized
    • BBB Pgp effluxes BBB --- non-sedative
  14. Cetirizine (Zyrtec)
    • 2G H1 receptor antagonist
    • metabolite of 1G hydroxyzine
    • COOH derivative so it does not cross BBB so much is excreted unchanged (typical of AA drugs) --- also decreases DDI
  15. Levocetirizine
    • racemic switch of cetirizine
    • claims of decreased sedation
  16. H2 receptor antagonists (blockers)
    Tx: gastric ulcers, GERD
  17. Cimitidine (Tagament)
    • H2 receptor antagonist
    • largely excreted unchanged
    • guanidine-like functional group
    • imidazole problem
    • binds to and inhibits a wide range of CYPs --- many DDIs
    • inhibits gastric alcohol dehydrogenase
  18. Ranitadine
    • H2 receptor antagonist
    • largely excreted unchanged
    • no imidazole ring --- only 10% as much CYP inhibition as cimitidine
    • "me better" drug of cimitidine
  19. Famotidine (Pepcid)
    • H2 receptor antagonist
    • no CYP inhibition
    • "me too" drug of cimitidine
  20. Nizatidine (Axid)
    • H2 receptor antagonist
    • 90% bioavailable
    • no CYP inhibition
    • "me too" drug of cimitidine
  21. Proton Pump Inhibitors (PPIs)
    • covalent binding to sulfhydryl group on parietal cells
    • targets proton and/or potassium pumps
  22. Omeprazole (Prilosec)
    • PPI
    • broad range of PD half life because it is a prototypic 2C19 inhibitor
    • 3A4 substrate
    • marketed as a racemic sulfoxide
    • enteric coated to prevent premature activation
  23. Tx: GERD
    PPI + amoxicillin + clarithromycin (H. Pylori)
  24. Esomeprazole (Nexium)
    • PPI
    • S-enantiomer eliminating 2C19 issues leading to predicatable plasma levels of parent drug and clarithromycin
    • dose: 2x of omeprazole
    • chiral center is at the S-sulfoxide group
  25. Lansoprazole (Prevacid)
  26. Pantoprazole (Protonix)
    • PPI
    • more acid stable so not affected by food stimulated acid production
  27. Rabeprazole (Aciphex)
    • PPI
    • sulfone group is acted on by 3A4 and the O-demethyl group is acted on by 2C19
  28. PPI PD:
    • irreversible long acting inhibitors of H+, K+ ATPase
    • forms cystine (disulfide) linkages with enzyme after prodrug is acid-activated to electrophilic sulfenamide
    • ion trapping effect at canaliculi
  29. Misoprostol (Cytotec)
    • Prostaglandin
    • Tx: anticulcer, NSAID-induced ulcers
    • opposes influence of HA on PP
  30. THC
    • marijuana
    • makes your hair grow --- Hippies!

Card Set Information

Pharm Chem Exam 1 Part 4
2012-01-27 22:04:44
Pharm Chem Exam Part

Pharm Chem Exam 1 Part 4
Show Answers:

What would you like to do?

Home > Flashcards > Print Preview