Week 9 - Classification of Antimicrobial Drugs Flashcards
A susceptible organism can be killed by different spectrums of drugs. What is a narrow spectrum, and what is a broad spectrum drug?
Narrow - Active against a few specific organisms
Broad - Active against a wide variety of organisms (save life until we can identify organism)
What is the MOA of antimicrobial drugs? (5)
- Inhibit bacterial cell wall synthesis, or activates enzymes that disrupt the cell wall
- Increase cell membrane permeability
- Inhibits bacterial synthesis of DNA and RNA, or disrupts DNA function
- Antimetabolites
- Suppresses viral replication
What are bactericidal drugs?
- cause lethal inhibition of bacterial protein synthesis
What are bacteriostatic drugs?
cause nonlethal inhibition of protein synthesis
What is empiric therapy? (3)
- identify microorganism and drug that it is susceptible to (goal is to narrow spectrum drugs)
- Broad spectrum is used in emergencies, but C&S must be collected prior to treatment
– suppressed results leading to inapropriate drug therapy
What is prophylactic therapy? (4)
- surgery
- Bacterial endocarditis
- Neutropenia
- other (chronic issues) ie. UTI
What is neutropenia?
- low neutrophils
What are 3 factors that modify drug of choice, route, or dosage for infections?
- Host defenses
- Site of Infection
- Other - allergic reactions
What are host defenses? (2)
- A well-functioning immune system works together with antimicrobial treatment in order to cure infection
- immunocompromised hosts require more rapid bactericidal
Which site of infections should we be cautious about when choosing drugs? (2)
- BBB (non-ionized)
- foreign material (prosthetics)
Drug misuse is very common. Give reasons as to why we cannot give certain drugs for:
1) treatment of viral infection
2) Treatment of fever of unknown origin
1) cannot give antibacterial for viral infections
- mumps, chickenpox, common cold do not respond to antimicrobials
2) Only consideration to give medication is if the host is immunocompromised
What other medication misuse occurs? (3)
- improper dose
- Improper identification of organism
- Improper cleansing of foreign material, exudate, or necrosis
What can antimicrobial misuse, along with nonadherence to completion of treatment cause?
antimicrobial resistance
What occurs in antimicrobial resistance? (2)
- Organism becomes less susceptible or sensitive to drug (often from broad spectrum)
- Pt does not respond to treatment, leading to complications
Why are hospital associated infections high?
- they are sites of intensive antibiotic use
