Biochem drugs

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Biochem drugs
2013-05-06 16:46:22

post midterm
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  1. Methotrexate (function)
    inhibit dihydrofolate reductase 

    decreased tetrahydrofolate synthesis, which results in reduced DNA relication in mammalian cells due to less purines synthesized
  2. Methotrexate (definition)
    • Cancer drug (chemotherapeutic);
    • treat leukemias 
    • Competitive inhibitor, 
    • folic acid analog
    • useful for rapidly growing cancers, but toxic to all dividing cells (hair, GI tract, respiratory tract, RBCs)
  3. sulfonamides (function)
    • inhibit Dihydroptroate synthase in tetrahydrofolate synthesis. 
    • Only works on bacteria (microorganisms) 
    • DNA synthesis stops because cells cannot divide due to decreased nucelotide synthesis. (purine)
  4. sulfondamides (definition)
    • anti-bacterial, 
    • for THF synthesis: PABA (p-aminobenzoic acid) analog. 
    • Competitive inhibitor
  5. Trimethoprim (definition)
    anti-bacterial drug;
  6. Trimethoprim (mechanism)
    inhibits dihydrofolate reducatse on PROKARYOTES.  

    reduced purine synthesis --> reduced DNA synthesis and inhibits cell divisions.
  7. Mycophenolic acid (definition)
    • immunosurpressant drug
    • prevent graft rejection
  8. Mycophenolic acid
    reversible uncompetitive inhibitor of inosine monophosphate dehydrogenase ( GMP synthase) 

    deprives rapidly proliferating T and B cells of key components of nucleic aicds.
  9. Allopurinol (definition)
    • anti-gout drug or treat hyperurecemia 
    • also known as Zyloprim, generic
  10. Allopurinol (mechanism)
    • non-competitive inhibitor of xanthine oxidase
    • to treat gout or hyperurecimea

    Xanthine or hypoxanthine are excreted in urine

    they are more water soluble thus, it's easier to get excreted in urine
  11. Colchicine (definition and mechanism)
    gout treatment: microtubule inhibitor

    inhibits migration of white cells to join where uric acid cystals are phagocytized. 

    DOES NOT reduces serum uric acid levels.
  12. hydroxyurea (definition and mechanism)
    antineoplastic drug 

    • inhibits ribonucleotide diphosphate reductase 
    • decreased deoxyribonucleoside diphosphate synthesis --> decreased DNA synthesis 

    used for chemotherapy
  13. 5-fluorouracil (definition)
    • cancer drug; 
    • (5-fluorouracil-containing RNA is more detrimental to Cancer cells than to normal cells)

    but it is non-selective; thus rapidly growing normal cells will be affected 

    AraC is commonly used to treat cancer
  14. 5-fluorouracil (mechanism)
    in dTMP (thymidine) synthesis from dUMP, 

    gets converted to 5 fluorodeoxyridylic acid (dFUMP), which inhibits thymidylate synthase 

    fluorine groups are the same size as hydrogen atom --> uracil analog 

    larger groups on bromodeoxyuridine and trifluorothymidine make them thymidine analogs.
  15. salycylates & sulfoneamides (function and affect)
    dissociate albumin-bilirubin complex and form unconjugated bilirubin in blood. (Heme degradation step) 

    free bilirubin can cross the blood-brain-barrier and form deposits on the filter --> cause Kernicterus
  16. disulfiram (mechanism)
    • -if ethanol is ingested, the amounts of acetaldehyde can increase by 5-10 folds. 
    • -side effects ie. flushing, nausea, are meant to prevent from consuming alcohol. 
    • -inhibits most of the acetaldehyde dehydrogenase in mitochondria isozyme.
  17. disulfiram (definition)
    • -antabuse
    • -treatment of alcoholism
    • -causes nausea and vomiting if alcohol is ingested
  18. acetadote ( function and mechanism)
    • -scavenger for NAPQ1, toxic compound formed from acetaminophen (tyrenol) during chronic alcoholic
    • -contains cysteine and used for gultathione synthesis
    • -
  19. phenobarbital (function and mechanism)
    increases and stimulates CYP 450 by 3-4 fold. 

    Phenobarbital needs heme group; administering this drug to patients with AIP will worsen the condition since it would stimulate more heme synthesis and results in increase of ALA ( GABA analog)
  20. Orlistat (function)
    • -Gastric& pancreatic lipase inhibitor
    • -inhibits the digestion of dietary fats (TAGs) 
    • -reduces dietary TAG absorption
  21. Sibutramine (function)
    an appetitie suppressant (increases the feeling of fullness) 

    helps to manage obesity
  22. Slow reacting substances of Anaphylaxis (SRS-A) (function)
    • -cysteinyl-leukotrienes (LTC, LTD, LTE) are components of SRS-A 
    • -more potent than histamine 
    • -increase vascular permeability 
    • -could also lead to severe bronchoconstriction, vasoconstriction and lung edema 
    • -LTC4 = + GSH
    • -LTD4 = - Glu
    • -LTE4 = -Gly 
    • -LTF4 = + Glu
  23. isoniazide (definition and use)
    a drug for tuberculosis 

    depletes PLP so needs to supply with vitamin B6 for patients.
  24. Non-steroidal anti-inflammatory drugs (NSAIDS) ( function)
    • - inhibit both COX-1 and COX-2
    • reduce inflammation 
    • -
  25. Aspirin (definition and function)
    • -NSAIDs 
    • -inhibit both COX-1 and COX-2 Irreviersibly by  acetylation of a serine residue (active site) 
    • -low dose of aspirin can act as anti-coagulant agent ( decrease clotting) 
    • -favors prostacyclin produced by COX-2 in endothelial cells while COX-1 in platelets cannot synthesize new enzymes
  26. Cortisol ( function in eicosanoids)
    • -glucocordico-steroids 
    • -inhibit PLA2 and COX-2 
    • -inhibits all prostacyclin, thoromboxane, and leukotriene synthesis
  27. Benoxaprofen (definition and function)
    • -anti-inflammatory drug
    • -inhibits 5-lipoxyogenase
  28. Zileuton (definition and function)
    • -anti-inflammatory drug
    • -inhibits 5-lipoxygenase
  29. Phenylbutazone (function and definition)
    • -inhibit COX-1 & COX-2 
    • -reversible inhibitor 
    • -NSAIDs
  30. Dazoxiben (function and definition)
    • -anti-coagulant drug
    • -inhibits thromboxane synthase
  31. Dipyridamole (definition and function)
    • -anti-coagulant drug
    • -inhibit thromboxane synthase
  32. Indomethacin (definition and function)
    • -NSAIDs
    • -inhibit COX-1 and COX-2
  33. Asthma Treatment (3 options)
    • 1. inhibit PLA2 
    • 2. inhibit 5-lipoxygenase 
    • 3. inhibit receptors for cysteinyl-leukotriene
  34. Zocor (definition and function)
    • Statin drugs
    • -inhibit HMG CoA reductase
    • -reduce cholesterol synthesis 
    • -competitive inhibitor, structurally analog to HMG CoA
  35. Lipitor (definition and function)
    • -Statin drug
    • -inhibit HMG CoA reductase
    • -reduce cholesterol synthesis 
    • -competitive inhibitor, structurally analog to HMG CoA
  36. Neomycin (function and definition)
    • -treatment for acquired hyperammonemia 
    • -reduction of bacterial urease in the gut
    • -
  37. lactulose (function and definition)
    • -treatment for acquired hyperammonia 
    • -digested by bacteria in colon to form Lactic acid to neutralize and excrete ammonia
  38. Paroxonase and PAF acetylhydrolase (not drugs, but enzyme) (function, definition)
    • -found in HDL
    • -enzymes that reduces LDL oxidation
  39. bile acid sequestering drugs
    • -bind to bile acids or bile salts in the intestine--> less dietary lipid digestion
    • -bile acids/salts get excreted in feces
    • -liver has to use new free cholesterol to resynthesize primary bile acids
    • -helps to reduce free cholesterol level in the liver. 
    • -increases hepatic LDL-receptor
    • -decreases serum LDL level
  40. Ezetimibe (definition and function)
    • -a new drug that blocks a transporter protein. 
    • -reduces cholesterol absorption
  41. Plant Stanols and Sterols (definition and function)
    • -treatment for hypercholesterolemias (type II and III)
    • -instead of using statin will inhibit dolichol and CoQ enzyme synthesis
    • -sterols and stanols will displace cholesterol from micelles during absorption into intestinal mucosal cells. 
    • -found in margarine or by pills.
  42. nitroglycerin (function)
    • -used in treatment of myocardial ischemia 
    • -coverted to NO --> vasodilation of coronary blood vessels
  43. sapropterin (definition and function)
    • -treatment of PKU
    • -synthetic form of BH4
    • -typically prescribed for mild forms of the disease
    • -patients with enzymes that has low affinity for the cofactor
  44. Phencyclidine (PCP) (definition and function)
    • antagonist to the NMDA (glutamate) receptor 
    • tranquilizer in animals 
    • hallucinogen in human
  45. cyanocobalamin (function)
    • -treatment for Pernicious anemia 
    • -B12 deficiency due to autoimmune destruction of pareital cells 
    • -prietal cells produces intrinsic factor, which helps to absorb B12
  46. Benzodiazepines (definition and function)
    • treatment for epilepsy (repeated seizures)
    • anxiety reducer (ie. valium)
    • bind to the GABA receptor
    • potentiates GABA
  47. diazotized sulfanilic acid (function and defition)
    • used for detecting bilirubin
    • (Van den Bergh rxn)
    • bilirubin reacts with diazo reagents- form red or purple colored complex
  48. Phenobarbital (in bilirubin)
    • -treatment for Criggler-Najjar syndrome type II 
    • -80 % of UDP-glucuronyl transferase is gone
    • -induces the synthesis of this enzyme to make more conjugate bilirubin
  49. Warferin
    • slow acting anti-coaggulant 
    • inhibits Vitamin K by blocking exposide reductase
    • Vitamin K is necessary cofactor for gamma-carboxylase, which carboxylates clotting factor II, VII, IX, X --> needed for better binding with platelet phospholipids
  50. Streptokinase (function)
    • -activate plasminogen 
    • -cleaves hard clot of fibrin and dissolute the clotting
    • (urokinase also breaks it down)
  51. Fomepizole (definition and function)
    • competitive inhibitor drug, EtOH derivative, for alcohol dehydrogenase
    • treat patients with methanol poisoning
    • when methanol is digested, it forms formaldehyde (toxin in brain and visual disturbance) 
    • the alcohol dehydrogenase has higher affinity for ethanol than methanol.
    • upon administration, treat them with sodium bicarb to neutralize the accumulated lactic acid (patients will have metabolic acidosis if just give them high EtOH) 
  52. Metformin (function)
    • decreases glucose output by liver
    • increase glucose utilization by muscle (insulin resistance is improved)
  53. Sulfonylurea (function)
    increase insulin secretion from pancreas
  54. tamoxifen (definition and function)
    • breast cancer drug
    • avoid consuming with grapefruit
    • grapefruit inhibit CYP3A4 --> enzyme necessary for digesting tamoxifen 
    • without this enzyme, tamoxifen is less effective
  55. Avidin (definition and function)
    • substance in white raw egg
    • inhibits biotin absorption
  56. Menaquinone (defition)
    • vitamine K 
    • formed by bacteria in intestine
  57. Phylloquinone (definition)
    Vitamin K- dietary source
  58. Statin drugs (3 kinds)
    • -Simvastatin (Zocov)
    • -Pravastatin (Pravacol)
    • -Lovastatin (Mevacor)