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)
Sulfamethoxazole + Trimethoprim, Co-trimoxazole, TMP-SMX (Bactrim) : SPECTRUM
- Bacteristatic or cidal?
a. When is it the other one? - What do Sulfa Drugs INHIBIT (What organisms)
- generally BACTERIOSTATIC
a. In the URINARY TRACT, a BACTERICIDAL CONCENTRATION can be reached! - G+ AND G-!
Sulfamethoxazole + Trimethoprim, Co-trimoxazole, TMP-SMX (Bactrim)
- DOC for what INFECTIONS?
- Prophylaxis Tx for what?
- for UTI INFECTIONS (first attack) (Co-trimoxazole)
2. PNEUMOCYSTIS JIROVECI infections in CHILDREN and in AIDS Pts.
Sulfamethoxazole + Trimethoprim, Co-trimoxazole, TMP-SMX (Bactrim): PHARMACOKINETICS
- How is it taken?
- Metabolized where?
- Freely cross what?
- ORAL (absorption is FAST). (Co-Trimoxazole is available for IV use but ONLY use in EXTREME SITUATIONS!)
- MAINLY in the LIVER as ACETYLATED PRODUCTS and Excreted mainly thru the KIDNEY!
- the Placenta and BBB
Toxicities of SULFA Drugs!
- High rate of what? (2nd to what class of drugs)?
- Other MAJOR SIDE EFFECT?
- SULFA DRUGS SHOULD NOT be GIVEN to whom?!
a. WHY?
- DRUG SENSITIVITY!: so ALLERGY. (PENICILLINS)
- STEVENS-JOHNSON SYNDROME
- to INFANTS less than 2 MONTHS of AGE; AVOID use near term or in nursing premature or jaundiced infants!
a. Due to KERNICTERUS (Sulfonamides compete w/binding of BILIRUBIN to PLASMA PROTEINS)
* NEONATES/Newborns: Dont use this and Phenicol (carbphenicol??maybe..)
Sulfamethoxazole + Trimethoprim, Co-trimoxazole, TMP-SMX (Bactrim)
RESISTANCE
- 3 places (think of mechanisms)
- Increased production of essential Metabolite or Drug Antagonist (PABA)
- Active Efflux or Decreased permeability
- Alternate Metabolic Pathway for Synthesis of Essential Metabolite (PLASMID)
Lipopeptide Antibiotics
- DAPTOMYCIN (CUBICIN)
a. Type of Protein?
b. Do they penetrate the BACTERIAL CYTOPLASM?
c. What does it do? (MOA)
- a. CYCLIC Lipoprotein
b. NO!
c. Binds to BACTERIAL MEMBRANES and CAUSE a RAPID DEPOLARIZATION of the MEMBRANE POTENTIAL (leads to loss of membrane potential causing inhibition of Protein, DNA, and RNA synthesis –> Cell Death)
Lipopeptide Antibiotics
- Daptomycin (Cubicin)
a. Forms what kind of channels?
b. What does this do?
- a. Transmembrane Channels
b. Leaks intracellular Ions and Depolarization to inhibit DNA, RNA, and Protein Synthesis!
Lipopeptide Antibiotics
- Daptomycin: SPECTRUM
a. Bacteriostatic or Cidal?
b. Work against what bacteria types?
c. Does resistance occur? - Drugs of first choice before using Daptomycin?
- a. Bactericidal
b. G+ (MRSA and MSSA: Concentration dependent); AEROBIC and ANAEROBIC
c. RARE. No mechanism of resistance to Daptomycin has been identified.
* NEVER A DRUG OF FIRST CHOICE due to its effects against MRSA and MSSA - Penicillin (ase resistance) for STAPH, if that doesnt work, then Vancomycin, if that doesnt work, then Ceptaroline, Benozalid (sp? last lecture) and Daptomycin
Lipopeptide Antibiotics
- Daptomycin: Pharmacokinetics
a. How is it given?
b. Half Life?
c. How does the body get rid of it?
2. Use is suitable when?
- a. IV
b. 8-9 hrs so only need ONCE DAILY DOSING!
c. Kidneys. - for EMPIRIC THERAPY in patients with SERIOUS G+ INFECTIONS (alternate to Vancomycin!)
Lipopeptide Antibiotics: Mupirocin (Bactroban)
- Made from what?
a. What does it INHIBIT?
b. How?
- When is it given frequently?
- Pseudomonas Fluorescens
a. PROTEIN and RNA SYNTHESIS!
b. Reversible binding to Bacterial Isoleucyl-t-RNA SYNTHETASE! (Affecting TRANSLATION!!) - BEFORE SURGERY (20% of peeps carry MRSA in their nose)
Lipopeptide Antibiotics: Mupirocin (Bactroban)
- Spectrum
a. Good against what?
b. Bacteriostatic/cidal?
c. How is it GIVEN?
- a. Good against G+ and some G-
b. Bacteriostatic at LOW CONCENTRATIONS and Bactericidal at HIGH CONCENTRATIONS
c. TOPICALLY to the skin or the nares
Lipopeptide Antibiotics: Mupirocin (Bactroban)
- Tx
a. Tx of what? This is caused by what?
b. INTRANASAL APPLICATION to patients who carry what?
c. Unique Mechanism, so it has little chance for what?
- a. IMPETIGO: S. Aureus, B-hemolytic Streptococci (including Streptococcus Pyogenes)
b. MRSA
c. for Cross-resistance with other Antibiotics
Polypeptide Antibiotics
- What 2 did we talk about?
- They’re MOSTLY USED for what infections?
- MOA
a. Polymyxin B binds to what? This binding does what?
b. Is it Bacteriostatic/cidal?
i. Exceptions?
c. NO EFFECT on what?
- Polymyxin B (know!) and Polymixin E
- G- INFECTIONS
- a. G- Bacterial CELL MEMBRANE PHOSPHOLIPIDS (Lipid A of ENDOTOXIN); it INCREASES permeability of the cell membrane causing LOSS of metabolites needed for bacterial existence
b. Bactericidal against MOST G- BACILLI!
i. Proteus and Neisseria Species
c. in G+ (dont have ENDOTOXIN)
Polypeptide Antibiotics
- Pharmacokinetics
a. No use how?
b. Binds very well to what?
c. Excretion thru Kidney is what? - Toxicity:
a. BIG ONE! - Use: How?
- a. No GI absorption (no oral use); Poor Parenteral use
b. to Plasma Proteins
c. SLOW - a. NEPHROTOXICITY: so ONLY USE it TOPICALLY!!
- Topical in combination with Neomycin and Bacitracin; and topical application to Wounds, burns, etc (Pseudomonas Infections) and the Eye.