exam 1 Flashcards
What are antimicrobials used for?
To treat infectious diseases
What is the definition of an antibiotic?
A chemical produced by one microbe that can harm other microbes
What is an antimicrobial agent?
Any agent that can kill or suppress microorganisms
What does selective toxicity refer to?
Toxic to microbes but harmless to the host
What are the two commonly used classification systems for antimicrobial drugs?
- Classification by susceptible organism
- Classification by mechanism of action
What are the two types of spectrum in antibiotic classification?
- Narrow spectrum
- Broad spectrum
What is the difference between bactericidal and bacteriostatic drugs?
- Bactericidal: Directly lethal to bacteria
- Bacteriostatic: Slows bacterial growth without causing cell death
What is acquired resistance to antimicrobial drugs?
When organisms develop resistance over time to one or more drugs
Name some organisms with microbial drug resistance.
- Enterococcus faecium
- Staphylococcus aureus
- Enterobacter species
- Klebsiella species
- Pseudomonas aeruginosa
- Acinetobacter baumannii
- Clostridium difficile
What is a superinfection?
A new infection that appears during the course of treatment for a primary infection
What are some strategies to delay the emergence of drug resistance?
- Promote adherence to appropriate prescribing guidelines
- Reduce demand for antibiotics among healthy adults
- Emphasize adherence to prescribed antibiotic regimens
What factors are considered in the selection of antibiotics?
- Identify organism
- Drug sensitivity
- Host factors
What is empiric therapy?
Antibiotic therapy for patients before the causative organism is positively identified
What must be ensured about antibiotics regarding dosage and duration?
Antibiotic must be present at the site of infection for a sufficient length of time
What is prophylactic use of antimicrobials?
Agents given to prevent infection rather than to treat an established infection
What is a principal adverse effect of penicillins?
Allergic reaction
What structural feature do penicillins have?
A beta-lactam ring
What is the mechanism of action of penicillins?
Weakens the cell wall, causing bacteria to take up excessive water and rupture
What are broad-spectrum penicillins also known as?
Aminopenicillins
Name two broad-spectrum penicillins.
- Ampicillin
- Amoxicillin
What are beta-lactamase inhibitors?
Agents that extend antimicrobial spectrum when combined with penicillinase-sensitive antibiotics
What is the therapeutic use of vancomycin?
Severe infections only, including MRSA and Clostridium difficile
What are the adverse effects of vancomycin?
- Ototoxicity
- ‘Red man’ syndrome
- Thrombophlebitis
- Thrombocytopenia
What are tetracyclines used to treat?
- Infectious disease
- Acne
- Peptic ulcer disease
- Periodontal disease
- Rheumatoid arthritis
- Mycoplasma pneumonia
- Lyme disease
- Anthrax
- Helicobacter pylori