Anti-infective Pharmacology Flashcards
(36 cards)
What are antibiotics derived from?
Derived from microorganisms
Ex. Penicillin, cephalosporins
- All antibiotics are antibacterial, not all antibacterials are antibiotics
How are antibacterial agents made?
Synthetic- made in a lab
Ex. Sulfonamides
- All antibiotics are antibacterial, not all antibacterials are antibiotics
What does bactericidal mean?
- Have ability to kill bacteria
- Irriversible process
What does bacteriostatic mean?
- Have the ability to inhibit or retard the growth of bacteria
- Reversible process (able to grow and multiply again)
What does spectrum mean?
Range of anti-infective properties
- May be narrow (few organisms)
- May be wide or broad (many organisms)
What is resistance?
- Ability of an organism to be unaffected by an anti-infective agent
- May be natural or acquired
What is suprainfection (superinfection)?
- Appearance of a new infection w/ other than the original organism while the pt. is taking an antimicrobial agent
- Above and beyond the initial infection
- Ex. Candidiasis as a result of taking tetracycline
What is synergism?
Effect of two agents used together is greater
What is antagonism?
Effect of two agents together is lesser or negated
What is the etiology of dental infection in the early stages?
Gram-positive aerobes
What is the etiology of dental infection in the middle and later stages?
Gram-positive and gram-negative anaerobic organisms increase until they coalesce into an abscess
What are first-line treatments?
Penicillin VK
Amoxicillin
What is an alternative agent to Penicillin and amoxicillin? What also needs to be taken?
- Alternative agent: clindamycin
- Adjunctive agent: metronidazole
- The alternative agent does not always cover all gram (-) anaerobes so we add an adjunctive agent
What is a second-line treatment? Why would we want to avoid this?
- Azithromycin (Z-Pack)
- Can cause drug interactions and arrhythmias
What drug interaction can happen when an antibacterial agent is used in a pt. taking Coumadin (warfarin)?
- Antibiotics reduce gastrointestinal flora that make vitamin K which means no clotting factors
- Increases the effects of warfarin (bleeding)
Why should bacteriostatic and bactericidal antibiotics not be used togther?
They will miss the anaerobes because they have slowed down
What interaction can occur between antibacterial agents and oral contraceptives?
Reduced effectiveness
What is the mechanism of action of penicillin?
Bactericidal: inhibits cell wall synthesis
What are the types of Penicilins?
- Narrow- penicillin VK
- Broad- amoxicillin
- Penicillinase-resistant- methicillin and amoxicillin+clavulanate (Augmentin)- used to treat MRSA
What are the uses and adverse effects of penicillins?
Uses: Treatment of abscesses and endocarditis prophylaxis
Adverse effects: Rash, GI distress
What is the mechanism of action of clindamycin (Cleocin)?
Dose dependent: Bactericidal (large dose) or bacteriostatic (small dose)
- Inhibits bacterial protein synthesis
- Retards bacterial growth and reproduction
When would clindamycin be used?
If a patient has a penicillin allergy
Patient care considerations for clindamycin (Cleocin)
High risk of pseudomembranous colitis
- Severe, persistant diarrhea
- Do not use anti-diarrheals
- Discontinue drug
Mechanism of action of Metronidazole (Flagyl)
Bactericidal (will kill C. dif)
- Causes bacterial DNA to lose structure
(End in -azole, but not an anti-fungal)
