Antibiotic Slide Deck - AGPC Flashcards
What are common causes of drug resistance?
- Overuse of broad-spectrum abx. - Over prescription of abx. for viral illnesses - Use of abx in animals that enter the food chain
Which type of bacteria has a cytoplasmic membrane surrounded by a touch rigid mesh cell wall?
Gram + organisms - Ex: staph aureus, strep pneumoniae, clostridium - stain purple
Which type of bacteria has a thin cell wall surrounded by a second lipid membrane?
Gram - organisms - Ex: E. coli, pseudomonas, H. pylori, Neisseria, gonerrhea, salmonella - stain pink
What type of organism needs oxygen to survive?
Obligate aerobes
What type of organism is poisoned by oxygen?
Obligate anaerobes
What type of organism can grow with or without oxygen because they can metabolize energy aerobically or anaerobically?
Facilitative anaerobes
What type of antibiotic stops the bacteria from growing but does not kill it?
Bacteriostatic
What type of antibiotic kills the bacteria?
Bactericidal - important to use this type in patients that are immunocompromised
Important factors to keep in mind when prescribing antibiotics:
- immune system function - renal and hepatic function - Age - Pregnancy/lactation - Risk for multi-drug-resistance organisms - Patient adherence: lowest frequency for the shortest duration - cost effective - for kids: taste good and most concentrated dose
What is the MOA of the penicillins?
Inhibit the biosynthesis of peptidoglycan bacterial cell wall
Penicillin V and Penicillin G Benzathine are active against what type of organisms?
Narrow spectrum - gram + mostly: S. pneumoniae, GABHS - bactericidal Pen V (oral) is best for group A beta-hemolytic strep - strep throat/pharyngitis Pen G (IV) best for syphilis infection (T. pallidum)
Amoxicillin and Augmentin (Amox/Clavulanic Acid) are active against what type of organisms?
More broad spectrum - Same gram + organisms as Pen V/Pen G but also some activity against gram - organisms - bactericidal Amoxicillin - 1st line for AOM and sinusitis Augmentin - 1st line fx for bites, UTI in pregnancy
PCNs ADRs
- serious allergic hx - Rash - GI (N/V/D) - Fungal overgrowth/candidiasis
Cephalosporin MOA
inhibit mucopeptide synthesis in the bacterial cell wall Bactericidal
Name common gram + organisms and where the common infections they cause
•Staphylococcus aureus -Commonly causes skin infections
–Can also cause endocarditis, sepsis, osteomyelitis, pneumonia
•Streptococcus
–Pyogenes (pharyngitis [GAS], impetigo, cellulitis)
–Pneumoniae (pneumonia, meningitis, sepsis)
–Agalactiae: meningitis, vaginitis [GBS], UTI, endocarditis, skin infection
•Enterococcus
–Anaerobic
–Can cause UTI, prostatitis, intra-abdominal infections, cellulitis, endocarditis
•Bacilli
–Lactobacilli -present in the mouth, vagina
–C. difficile
Name common gram negative organisms and the infectiosn they cause
•Escherichia coli
–Found in the intestines of humans and animals
–Responsible for food-borne illness and UTI
–Can also cause cholecystitis, traveler’s diarrhea and sepsis
•Pseudomonas aeruginosa
–Most common in hospitalized patients
–Can cause otitis externa, Pneumonia, wound infection, UTI, sepsis
•Klebsiella pneumoniae
–Colonizes the human mouth and gut
–Commonly causes Pnuemonia, UTI, sepsis
- Neisseria gonorrhoeae
- Haemophilus influenzae
–Pneumonia bronchitis, otitis media, cellulitis, infectious arthritis
How does spectrum of activity differ between classes of cephalosporins?
Earlier generations have good gram + coverage and less gram - coverage
Later generations have better gram - coverage and less gram + coverage
Cephalosporins ADRs
C. diff, hypersensitivity rx, hemolytic anemia, neutropenia, leukopenia, coagulation abnormalities
Cephalosporins cautions/CIs
- hx of PCN allergy with anaphylaxis or hypersensitivity rx - safe in pregnancy/lactation and pediatrics
The stronger the drug (5th generation is strongest; 1st generation is weakest) - the more chance of a C. Diff infection
What drug is in the glycopeptide class?
Vancomycin (PO)
Vancomycin MOA and indication
- inhibits cell wall synthesis by binding to the D-A1a-D-A1a protein in the cell wall - oral is not well absorbed - stays in the GI tract - used for C. diff. infection
Vancomycin (oral) ADRs
- ototoxicity - nephrotoxicity ** monitoring for hearing and renal function
Lincosamides active against/MOA
Clindamycin - Gram + organisms - bacteriostatic - MRSA skin infections, dental infections, acne (topical) - inhibits protein synthesis by binding to the 50S subunit of bacterial ribosome
High risk for C. Diff
Clindamycin pt education
- take w/ full glass of water - sit or stand for 30 minutes after dose - call clinic if diarrhea occurs
