Pharm Week 3 Flashcards
How are antimicrobials different from other classes of drugs
The exert their action on bacteria infecting the host not the host itself
How can you prevent resistance
Dual therapy= using two drugs with different mechanisms of action
Ex: TB, pseudomonas aeruginosa, and enterococcal endocarditis
Things to avoid when prescribing antimicrobials
- misuse of anitbiotics
- overuse of broad spectrum antibiotics
- suprainfection (alterations of normal flora= yeast infection from too strong of an antibiotic)
Should you leave colonized flora in tact?
Yes
Pathogen
Organism causing active infection
Normal flora
Organisms normally found on the host: non pathogenic
Colonization
Presence of bacteria that are not causing disease
Do you culture otitis media, sinus infection, or UTI in otherwise healthy patients?
NO
How do you select your appropriate antimicrobial
- Spectrum of activity
- Effects on non-targeted microbial flora
- Appropriate dose
- Pharmacokinetic and pharmacodynamic properties
- ADR’s
- Drug interactions
- Cost
What is Empirical Therapy
An educated guess based on patient and antimicrobial specific factors: anatomical location, pathogens associated with presentation, potential for ADR’s, and antimicrobial spectrum of activity
What are patient specific considerations in antimicrobial selections?
- Recent previous antimicrobial exposure
- anatomical location
- Hx of drug allergies
- Organ dysfunction affecting drug clearance
- Immunosuppression
- Pregnancy
- Compliance
De-escalation
If you’re using a broad spectrum antimicrobial and you ID the pathogen with culture results, you narrow your antibiotic to something sensitive to the pathogen
What causes antimicrobial failure?
- Inadequate diagnosis
- Poor source control (removing catheters or draining an abscess)
- Development of new infection with resistant organism
- Non adherence
- Insufficient dosing
- Drug interactions
- Suprainfections
MIC
Minimal Inhibitory Concentration: you have to be above the MIC to effectively kill the pathogen
Gram positive
Has a cell wall and cell membrane, will hold the purple stain
Gram Negative
Has cell wall, cell membrane, and outer envelope which inhibits pink stain from sticking
Atypical
Possess uncommon qualities, colorless after staining, not a typical cell wall, can replicate, they ARE common
Anaerobic
Do not require O2 to live
What are the types of bacterial classification?
Gram Positive
Gram Negative
Anaerobic
Atypical
B-Lactam Antibiotics
Selectively interfere with the synthesis of the peptidoglycan bacterial cell wall. They are divided based on chemical structure and spectrum of activity
Why do you dose antimicrobials around the clock? q4h
antibiotics work best if the drug dosing trough concentration remains above the MIC throughout the entire dosing interval
Penicillin
Founded by Alexander Flemming on accident in 1929. It is the least toxic drug known, members of the family differ by a single side chain (R group)
Penicillin mechanism of action
interfere with bacterial wall synthesis by binding to PBP’s (penicillin binding proteins) disrupting the peptidoglycan layer
Penicillin therapeutic uses
treatment for bacterial pathogens
