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2010-03-31 17:03:03
2 2_Pharm overview

2.2 Pharm review
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  1. Q: What are the four important questions to answer before prescribing an antibiotic?
    A: 1. Disorder is caused by infection. 2. Infection is a threat to patient. 3. Infection is sensetive to drug. 4. Appropriate route of administration.
  2. Q: What four characteristics are important when proposing a drug:
    A: 1. effectiveness. 2. toxicity 3. spectrum 4. expense.
  3. Q: Patient factors to consider when prescribing a drug?
    A: 1. History of clinical illness. 2. Ongoing pathologies. 3. Immune system status.
  4. Q: What are two exceptions to the rule that one should wait for organism culture before beginning antibiotic therapy?
    A: 1. Gross appearance of infection is sufficient to diagnose. 2. Serious infection.
  5. Q: Should one always culture as a backup, even if one has begun broad-spectrum therapy?
    A: Yes, always culture as a backup.
  6. Q: What does MIC stand for?
    A: Minimum Inhibitory Concentration, important in determining drug sensitivities of the organism.
  7. Q: Should "overkill" drug concentrations be used in therapy?
    A: Yes, because actual MIC at site of infection is unknown, high concentrations are bacteriocidal rather than bacteriostatic, and it discourages resistance.
  8. Q: How is antibiotic treatment initiated?
    A: ASAP and at the largest possible dose.
  9. Q: How long after infection symptoms end should a patient continue treatment?
    A: At least two days.
  10. Q: For what two reasons should one monitor drug concentrations?
    A: 1. As a guide to dose. 2. To mimimize intoxication.
  11. Q: What two distribution principles should be considered in relation to the blood brain barrier?
    A: 1. Lipid solubility of the drug. 2. Active transport out to the CSF.
  12. Q: What two distribution principles should be considered in relation to urine?
    A: Resorption and active transport, both of which can concentrate drugs in the urine up to one thousand times.
  13. Q: How does an ideal antimicrobial drug effect microorganisms versus host?
    A: An ideal antimicrobial drug ONLY effects the microorganism, not the host.
  14. Q: What is meant by the term broad spectrum antibiotic?
    A: Drugs that are active against a large number of pathogens of many different types.
  15. Q: Is a drug's spectrum of action the same as its useful therapeutic range?
    A: No.
  16. Q: Give 5 reasons why we use a therapeutic agents in combination.
    A: 1. To improve efficacy. 2. Initial treatment of serious infection. 3. Treatment of mixed infections. 4. Allows use of lower, less toxic doses. 5. Prevent resistance.
  17. Q: When might one consider prophylactic antimicrobial therapy?
    A: Surgery, travel in undeveloped countries, and epidemics.
  18. Q: What justifies prophylactic antimicrobial therapy?
    A: 1. Probability of infection is greater than 5 percent. 2. Drug has high therapeutic index. 3. History of prophylactic succes with drug.
  19. Q: What are the four sources of drug resistance mutations and genes?
    A: 1. spontaneous mutation. 2. transformation. 3. transduction (significant). 4. Conjugation (very significant).
  20. Q: How can you reduce the frequency of drug resistant strains?
    A: Decrease overall frequency of use of drugs.
  21. Q: What is cross resistance?
    A: When a drug resistance mechanism makes an organism resistant to many drugs within a class and possibly across classes.
  22. Q: Where is drug resistance most common?
    A: In the hospital setting.
  23. Q: Can hospitals reduce drug resistance by implementing controls through protocol?
    A: Yes.
  24. Q: What are 4 common adverse effects of antimicrobial action?
    A: 1. Superinfection. 2. Hypovitaminosis. 3. Surge of microbial toxin release. 4. Diarrhea.
  25. Q: What type of antibiotic is more likely to result in a superinfection?
    A: A broad spectrum antibiotic is more likely to result in superinfection than a narrow spectrum.
  26. Q: What are two adverse effects of antimicrobial drugs that are independent of drug mechanism?
    A: Irritation and allergy.
  27. Q: How is Isoniazid used therapeutically?
    A: Primary drug in all regimens, also prophylaxis.
  28. Q: How is Rifampin used therapeutically?
    A: Excellent tuberculicidal drug, most rapid acting. Also useful for other bacterial infections.
  29. Q: How is Ethambutol used therapeutically?
    A: Very effective with Isoniazid.
  30. Q: How are Pyrazinamide and Streptomycin used therapeutically?
    A: Used when organism is resistant to Isoniazid, Rifampicin, and Ethambutol.
  31. Q: What are some of the difficulties with tuberculosis therapy?
    A: Immunosuppressed patients, long therapy (6-24 months), organism grows slowly, rapid development of resistance, and all useful drugs possess toxicity problems.
  32. Q: What is the mechanism of action of Isonizid?
    A: Inhibit synthesis of mycolic acid and DNA synthesis.
  33. Q: Is Isoniazid bacteriostatic or bacteriocidal?
    A: Static is bacilli are resting, cidal if bacilli are growing.
  34. Q: What are the toxicities associated with Isoniazid?
    A: Peripheral neuritis, hepatitis, and hypersensitivity reactions.
  35. Q: What is the mechanism of action of Rifampin?
    A: inhibits RNA polymerase.
  36. Q: What are the toxicities associated with Rifampin?
    A: Jaundice, tears and urine turn red-orange, induces hepatic metabolism of other drugs, GI distress, diarrhea.
  37. Q: What is the mechanism of action of Ethambutol?
    A: Tuberculostatic, so never used alone.
  38. Q: What are the toxicities associated with Ethambutol?
    A: Decreased visual acuity, impaired ability to perceive green, and may precipitate gout.
  39. Q: What is the mechanism of action of Streptomycin?
    A: Aminoglycoside (same limited distribution and toxicities), must be administered parenterally.
  40. Q: What are the toxicities associated with Streptomycin?
    A: Ototoxicity, vestibular toxicity, and nephrotoxicity.
  41. Q: What is the mechanism of action of Pyrazinamide?
    A: Bactericidal
  42. Q: When is Pyrazinamide used?
    A: When resistance problems require a third drug.
  43. Q: What are the toxicities associated with Pyrazinamide?
    A: Liver necrosis, hyperuricemia, nausea, and vomitting.