Antibiotic Slide Deck 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 +
Ex: staph aureus, strep pneumoniae, clostridium - stain purple
Which type of bacteria has a thin cell wall surrounded by a second lipid membrane?
Gram -
Ex: E. coli, pseudomonas, H. pylori, Neisseria, gonerrhea, salmonella - stain pink
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?
Are they narrow or broad-spectrum?
Narrow spectrum
Most effective against gram +
Mostly:
- S. pneumoniae, Group A strep (GABHS) –> bactericidal Pen V (oral) is best for group A beta-hemolytic strep - strep throat/pharyngitis
- syphilis infection (T. pallidum) –> Pen G (IV) best for
Amoxicillin and Augmentin (Amox/Clavulanic Acid) are active against what type of organisms?
Broad spectrum, bactericidal
Gram +/-
- Amoxicillin* - 1st line for AOM and sinusitis
- Augmentin* (Amox/Clavulanic acid) - 1st line fx for bites, UTI in pregnancy
PCNs Adverse Drug Reactions (ADR)
- serious allergic hx (anaphylaxis)
- Rash - Stevens-Johnson syndrome
- GI (N/V/D)
- possible C.Diff associated diarrhea (CDAD)
- Fungal overgrowth/candidiasis - Vaginitis
Cephalosporin MOA
- Inhibit mucopeptide synthesis in the bacterial cell wall Bactericidal
- 5 generation that is increasing in gram (-) coverage and less gm (+) coverage
Common Gm (+) and where the common infections they cause
•Staphylococcus aureus
- Commonly causes skin infections
- Can also cause endocarditis, sepsis, osteomyelitis, pneumonia
- -Methicillin-resistant (MRSA) and methicillin-sensitive (MSSA)*
•Streptococcus Groups A,B,C,F,G
–Pyogenes (pharyngitis [GAS], impetigo, cellulitis)
–Pneumoniae (pneumonia, meningitis, sepsis)
–Agalactiae (meningitis, vaginitis [GBS], UTI, endocarditis, skin infection)
– Significant Macrolide resistance
•Enterococcus faecalis
–Anaerobic
–Can cause UTI, prostatitis, intra-abdominal infections, cellulitis, endocarditis
•Bacilli
–Lactobacilli -present in the mouth, vagina
–C. difficile
•Listeria
Common Gm (-) organisms and the infections they cause
•Escherichia coli
–Found in the intestines of humans and animals
–Responsible for:
- f_ood-borne illness (traveler’s diarrhea)_
- UTI
- cholecystitis, 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 Pneumonia, UTI, sepsis
– Risks: ETOH use, DM
•Neisseria gonorrhoeae
•Haemophilus influenzae
–Pneumonia, bronchitis, otitis media, c_ellulitis, infectious arthritis_
How does the spectrum of activity differ between generations 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-associated infx in adults (Clostridioles)
- Hypersensitivity rx (most common) - cross rx PCN allergy (anaphylaxis, rash)
- Hemolytic anemia,
- Neutropenia, Leukopenia,
- Coagulation abnormalities (thrombocytopenia)
Cephalosporins cautions/CIs
- hx of PCN allergy with anaphylaxis or hypersensitivity rx
- -safe in pregnancy/lactation and pediatrics
- The stronger the drug (later generation)-the more chance of a C. Diff infection
What drug is in the glycopeptide class?
Vancomycin (PO)
Vancomycin MOA and indication
MOA: inhibits cell wall synthesis by binding to the D-A1a-D-A1a protein in the cell wall; narrow, only Gm+
- oral is not well absorbed so usually IV admin
- stays in the GI tract
- used for C. diff. infection (given only orally for C.diff)
- Corynebacterium, Listeria, Lactobicillus, Actinomyces, Clostridium
Vancomycin (oral) ADRs
- ototoxicity
- nephrotoxicity
** monitoring for hearing and renal function
Lincosamides Class (Clindamycin) active against/MOA
Clindamycin
narrow, Gm + , bacteriostatic
MOA: inhibits protein synthesis by binding to the 50S subunit of bacterial ribosome
Indications: MRSA skin infections, dental infections, acne (topical)
-Carries highest risk for C. Diff
Clindamycin: education
- take w/ full glass of water
- sit or stand for 30 minutes after dose
- call the clinic if diarrhea occurs