Antimicrobial treatment

  1. Types of drugs
    • Antibacterial- substance produced by a living organism (naturally produced) that inhibits the growth of bacteria
    • Antifungal
    • Antiviral
    • Antiparasites : anti-helminthics , antiprotists
  2. Targets of antibacterials
    • Action of the drug and chemical structures
    • Cell wall- inhibits cell wall synthesis (penicillin)
    • DNA- how DNA is replicated (rifamycin)
    • Protein syntheis- how proteins are made (tetracycline)
    • RNA- how RNA is made or wroked on
    • Metabolic distruption- interrupt normal metabolic processes (sulfanilamid)
    • Membrane function- (polymeric)
  3. Use of antibacterials
    • Selective toxicity- toxic to bacteria and not to us
    • Bacteriostatic- how they affect the bacterial cell- once you take the drug/ environment away, the bacteria will start replicating again
    • Bacteriocidal- how they affect the bacterial cell- don’t have to apply it for a very long time
    • Therapeutic index- a number that informs us how good/ effective a drug is, effects the minimum toxic dose to the patient /(over) the minimum effective dose to kill the microbe
    • Half-life- eliminatablity- drug sticks around in the body long enough to be effective but not to stick around forever, must be able to eliminate eventually
    • Drug interactions- administer a drug to fight infection, is it going to be effective where we want it to be
  4. Broad Spectrum vs. Narrow Spectrum
    • Narrow-spectrum- describes the target of the drug- effective against a limited number of organisms, in virtue of their genitic makeup/ cell wall type/ some characteristic
    • Broad-spectrum- describes the target of the drug- effective against a wide range of organisms
  5. Beta Lactams
    • Famalies of drugs that have been altered to change the compotition
    • makes the drug more effective or turns it into a broad spectrum
    • They interfere with the peptidoglycan cross links
    • ex- Penicillins and Cephalosporins
    • Cephalosporins- 1st generation- only gram +, 2nd generation- gram + and gram -, 3rd generation- pseudomonades and some gram - (shifted spectrum but did not grow it)
    • Penicillin G- effective against gram + cells, can't get into Gram - cells, not resistant to stomach acid, needs to be injected
    • Penicillin V- acid resistant
    • Ampicillin broad spectrum and acid resistant
    • Methicillin- penicillinase resistant- doesn’t react with the beta lactam ring
  6. Tetracylcines
    Broad spectrum drugs that interfere with ribosome function by sitting in the ribosome during translation
  7. Sulfa Drugs
    • inteferes with folic acid production
    • bacteria cells make their own folic acid which is PABA
    • sulfa drugs interfere with this becasue it looks like PABA
    • Ex- sulfanilamide
  8. Quinolones
    • interfere with DNA (gryase inhibitors)
    • gyrase- super coling of DNA
    • Without gyrase, the circular DNA will burst when trying to open it to replicate
    • Ex- Ciprofloxacin
  9. Antifungals
    • Antifungals- Amphotericin B- interferes with cell membrane of fungal cells
    • Antivirals- Acyclovir- interfere with viral nucleic acid function, used for herpes, Amantadine- blocking adherence of the virus to the target cell, used for influenza, Protease inhibitors- used for HIV, breaks the viral polypeptide
    • Antiparasitics- Chloroquine- reduces severity of outbreaks
  10. Drug Resistance
    • Acquisition of R plasmids- done by conjugation, transformation and transduction
    • Mutation of drug target- Ribosome changes, RNA polymerase changes, Multi drug pumps
  11. Reasons of drug resistance
    • Improper use of antimicrobials- Using antibiotics when you shouldn’t
    • Overuse of antimicrobials- Using to much of antibiotics
    • Not taking all of the given medication
  12. Proper use of antimicrobials
    • Proper drug choice- infectious agent isn't responding to antibiotic, change antibiotic
    • Proper dose- maintaining the dose in the body
    • Proper drug therapy- completion of treatment
    • Using prescribed drugs- not sharing drugs
    • Expiration dates- less effective dose after expiration date
  13. Super infections
    • Caused by improper use (overuse) of drugs
    • Development of drug resistant organisms that may develop into diseases
    • Loss of competition (of normal microbiota in the body)
    • Ex- Candida albicans- Fungal member of normal microbiota. Long term treatment for something with antibiotics will wipe out bacterial microbiota causing a fungal infection
Card Set
Antimicrobial treatment
final review