Lecture 8, 9, and 10 Flashcards
Antibiotics?
(Chemicals produced by microorganisms)
-Inhibit growth of or kill other microorganisms
-Can be natural products as well as synthetic drugs
-Selective toxicity
Selective Toxicity?
Kill or damage a microbe without damage to the host
How to Achieve Selective Toxicity?
Antibiotics target cellular differences between host and pathogenic microbe
How to Achieve Selective Toxicity?
Antibiotics target cellular differences between host and pathogenic microbe
Therapeutic Index?
Ratio of the toxic dose to the effective dose of the drug
TI?
(Therapeutic Index)
Cidal?
KILL (lysis of cell wall to cause death)
Static?
INHIBIT (stop bacteria from growing (does not kill))
Human Body have natural defense to Bacteria?
1) Barriers: ex. skin and mucous membranes
2) Responses: antibodies, complement system, etc.
Human body naturally kills?
Pathogenic Microbes
Antimicrobials are used when?
Natural Defenses are overwhelmed or damaged
Bacteriostatic?
Inhibit bacterial cell replication but do not kill the organism at clinically achieved concentrations
Bacteriostatic Drugs?
(STATEC)
-Tetracyclines
-Erythromycin
-Chloramphenicol
Bactericidal?
Causes microbial cell death and lysis at clinically achieved concentrations
Bactericidal Drugs?
(PACS A PUNCH)
-Penicillins
-Aminoglycosides (Gentamycin, Tobramycin)
-Cephalosporins
Sulfonamides?
Either -cidal or -static according to composition of the environment
Sulfonamides Examples?
-Blood
-Pus
-Urine
Bactericidal drugs at low concentrations can behave as?
Bacteriostatic
Bacteriostasis if continued long enough will?
Decrease bacterial viability
Distinction between -cidal and -static antimicrobials can be important in?
Selection of therapy, especially in patients with a compromised immune system
Cell Wall Synthesis?
-Penicillin (G, Ampicillin)
-Cephalosporin (Ceftriaxone, Ceftaroline)
-Carbapenems (Imipenam)
-Monobactams (Aztreonam)
-Vancomycin (Tricyclic Glycopeptide)
DNA –> RNA?
-Quinolones (DNA gyros, Replication (Ciprofloxacin, Levofloxacin))
-Rifampin (RNA Polymerase)
-Metronidazole (Damage DNA)
Protein Synthesis?
-Tetracyclines (Doxycycline)
-Aminoglycosides (Gentamycin, Tobramycin)
-Chloramphenicol
-Macrolides: Azithromycin, Erythromycin
Cell Membrane?
-Polymyxins
-Daptomycin
Folic Acid?
-Trimethoprim
-Sulfonamides (Sulfamethoxazole)
“Please Come C My Vehicle”?
(Cell Wall Synthesis)
-Penicillin (G, Ampicillin)
-Cephalosporin (Ceftriaxone, Ceftaroline)
-Carbapenems (Imipenam)
-Monobactams (Aztreonam)
-Vancomycin (Tricyclic Glycopeptide)
“MR. Q”?
(DNA –> RNA)
-Quinolones (DNA gyros, Replication (Ciprofloxacin, Levofloxacin))
-Rifampin (RNA Polymerase)
-Metronidazole (Damage DNA)
“MCAT”?
-Tetracyclines (Doxycycline)
-Aminoglycosides (Gentamycin, Tobramycin)
-Chloramphenicol
-Macrolides: Azithromycin, Erythromycin
Determinants of Bacterial Response to Therapy?
(Reasons why a patient may NOT respond to therapy with antibacterials)
1) Misdiagnosis
2) No Infection
3) Do not complete full length of therapy
4) Patient self-treatment of infections with antimicrobials that were not prescribed for them
A virus is not?
A bacteria
Factors to consider when treating an infection?
1) Sensitivity of organism to drug (drug resistance)
2) Appropriate dosage (adult vs. neonatal)
3) Route of administration (PO vs. IV)
4) Duration of therapy (7 days vs. 14 days)
5) Special patient features (ex. immune system, age, renal function)
All drugs are excreted through the kidneys except?
Doxycycline
Indigenous Microbial Flora serve to?
Control growth of potentially pathogenic microbes
Use of an antimicrobial agent might disturb?
Ecologically balance leading to overgrowth of pathogenic microbes which are inherently resistant to antimicrobial agent (Superinfection)
Examples of IMF?
-C. Diff
-C. Albicans
(Use Vancomycin)
Vancomycin is used for?
C. Diff
Burns?
(SSP)
-Staph
-Strep
-Pseudo aeru
Skin Infections?
(SSH)
-Staph
-Strep
-Herpes