Pharm: L29: Fluoroquinolones and Sulfonamides Flashcards
Fluoroquinolones (-oxacin)
- What 7
- CIPROFLOXACIN (P. AERUGINOSA!)
- Ofloxacin
- Norfloxacin
- Levofloxacin
- Moxifloxacin (Penicillin resistant S. Pneumoniae and ANAEROBES!)
- Gatifloxacin
- Gemifloxacin (Active against Penicillin Resistant S. Pneumoniae, ANAEROBES, and CAP)
Fluoroquinolones
- Medically important ones are SYNTHETIC FLUORINATED ANAOLOGS of what Acid?
- NALADIXIC ACID!
Fluoroquinolones: MOA
- What do they INHIBIT?
a. What does this prevent happening? - What else do they inhibit?
a. What does this interfere with?
- DNA GYRASE
a. Prevents relaxation of Positively Supercoiled DNA that’s needed for NORMAL TRANSCRIPTION and REPLICATION - TOPO IV
a. Separation of replicated chromosomes to Daughter cells
Fluoroquinolones: MOA (2)
- Bacteriostatic/cidal?
- Bactericidal!
Fluoroquinolones: Spectrum
- Work BEST against what?
a. They also have good coverage for what? - Antipseudomonal?
- It’s really good as a PROPHYLACTIC AGENT AGAINS WHAT?
a. Which is the DOC? - Not effective against what type of infections?
- AEROBIC G- RODS!
a. GOOD G+ (includes MRSA and Penicillin Resistant S. Pneumoniae (Moxi and Gemi-) - YES (Cipro-)
- ANTHRAX
a. CIPRO - ANAEROBIC INFECTIONS (except for Gemi-, Moxi-, and Trova- Floxacin)
Fluoroquinolones: Pharmacokinetics
- How do we take them?
a. Decreased absorption with what 3 minerals?
b. Distribution?
2. CNS Penetration?
- How does the body get rid of them?
a. Can be BLOCKED by what drug?
- ORAL
a. Calcium, Magnesium, Iron (DONT TAKE WITH FOOD!)
b. Wide. Good Tissue Penetration. (PROSTATITIS: NORFLOX/OFLOX)
2. POOR
- KIDNEY
a. by PROBENECID
Fluoroquinolones: Resistance
- Big thing (Think of mechanism)
- What else can happen?
- MUTATION (in DNA GYRASE Enzyme)
2. Decreased permeability of the Bacteria; Antibiotic Modification (Ciprofloxacin)
Fluoroquinolones: Adverse Effects
- BIG THING?
- What other 2 things are important to remember?
- CI in what?
- GI DISTURBANCES
- CARTILAGE EROSIONS, TENDON RUPTURE
- PREGGERS and CHILDREN (CARTILAGE DAMAGE) < 18 YEARS
Metronidazole: MOA
- Prodrug: What happens?
a. Only found in whom? - Metronidazole metabolites are taken up into what?
a. Bacteriostatic/cidal?
- Non-enzymatically reduced by reacting with REDUCED FERREDOXIN
a. FERREDOXIN only found in ANAEROBES! - BACTERIAL DNA (make unstable molecules)
a. Bacteriocidal!
Metronidazole: Spectrum
- WORKS REALLY WELL AGAINST WHAT type of Bacteria (aerobes or Anaerobes)?
a. What specifically? - Used best for Treatment of what?
- What else?
- ANAEROBES
a. G- and G+ BACILLI (anaerobes) - PSEUDOMEMBRANOUS COLITIS, abdominal infections (anaerobic or MIXED infections)
- H. Pylori eradication w/a multi-drug regimen
Metronidazole: Pharmacokinetics
- How is it taken?
- How does the body get rid of it?
- Oral, IV, Topical
2. Liver metabolism and Eliminated in the Urine
Metronidazole: Adverse RxNs
- What SUPERINFECTION?
- What else?
- Candida Superinfection!
2. GI, CNS and PNS toxicity, Hypersensitivity
Sulfonamides
- Oral, Parenteral drug?
- Topical? **
- Sulfamethoxazole + Trimethoprim, Co-trimoxazole, TMP-SMX (Bactrim)
- Silver Sulfadiazine (Burns) (Silvadene) (*JUST KNOW THAT ITS TOPICAL)
* Trimethoprim is not a sulfonamide.
Sulfonamides: (Antimetabolite)
- They’re Antimetabolites: They compete with what?
a. This is for incorporation into what?
b. Bacteriostatic/Cidal?
- PABA
a. into FOLIC ACID
b. Bacteriostatic
Sulfonamides:
- Sulfamethoxazole
a. What does it do? - Trimethoprim
a. Prevents REDUCTION of what?
b. It’s essential for what? - What’s the purpose of these 2 molecules?
- a. Competes with PABA in making Bacterial FOLIC ACID (unique step for BACTERIA)…we as humans have to get Folic Acid from our Diet
- a. of Dihydrofolate to Tetrahydrofolate
b. It’s ESSENTIAL for 1 Carbon Transfer - They have a SYNERGISTIC RELATIONSHIP!!
a. Sulfonamides Compete with PABA at Dihydropteroate Synthase
b. Triethoprim inhibits Dihydrofolate Reductase (or competes there to prevent Dihydrofolic Acid from being converted to Tetrahydrofolic Acid)