Antibiotics Flashcards
Sub-classes of Beta lactams
- Penicillins,
- Cephalosporins,
3.Carbapenems, - Monobactams
Penicillins: Sub-classes & Coverage
1.NATURAL PENICILLINS: PENICILLIN G,(Benzylpenicillin)
PENICILLIN V (Phenoxymethylpenicillin)
(NARROW-SPECTRUM, GRAM-POSITIVE)
PENICILLIN G administration
Penicillin G - administered intravenously or intramuscularly due to its instability in the stomach
Penicillin V - administration
Penicillin V - orally as it is more stable in acidic environments.
Beta-lactams- aminopenicillins
AMOXICILLIN, AMPICILLIN (EXTENDED-SPECTRUM, SOME GRAM-
NEGATIVE)
Beta-lactams- Penicillinase resistant
OXACILLIN, NAFCILLIN (RESISTANT TO BETA-LACTAMASE ENZYMES
Beta-lactams- EXTENDED-SPECTRUM PENICILLINS
EXTENDED-SPECTRUM PENICILLINS: PIPERACILLIN
(ENHANCED GRAM-NEGATIVE, PSEUDOMONAS)
The main subgroups of Beta-lactams are
4
Cephalosporins generations
1st Gen: Cephalexin (Gram-positive, some Gram-negative)
2nd Gen: Cefuroxime (expanded Gram-negative)
3rd Gen: Ceftriaxone (broad Gram-negative, better CNS penetration)
4th Gen: Cefepime (Pseudomonas)
5th Gen: Ceftaroline (MRSA coverage)
5th Gen cephalosporins coverage
Ceftaroline (MRSA coverage)
3rd gen coverage
3rd Gen: Ceftriaxone (broad Gram-negative, better CNS penetration)
Glycopeptide coverage
Spectrum: Gram-positive, including MRSA and C. difficile
Aminoglycosides moa
INHIBIT PROTEIN SYNTHESIS BY BINDING TO THE 30S RIBOSOMAL SUBUNIT
Egs of Aminoglycosides
GENTAMICIN,
AMIKACIN,
TOBRAMYCIN
SPECTRUM of Aminoglycosides
GRAM-NEGATIVE,
ESPECIALLY PSEUDOMONAS
Aminoglycosides pharmacology
CONCENTRATION-DEPENDENT KILLING, SYNERGISTIC WITH BETA-
LACTAMS
Macrolides MOA
INHIBIT PROTEIN SYNTHESIS BY BINDING TO THE 50S RIBOSOMAL SUBUNIT
Coverage of Macrolides
GRAM-POSITIVE,
ATYPICAL BACTERIA (E.G.,
MYCOPLASMA, CHLAMYDIA)
Macrolides egs
ERYTHROMYCIN,
AZITHROMYCIN,
CLARITHROMYCIN
Tetracycline moa
Inhibit protein synthesis (bind to the 30S ribosomal subunit)
Egs of Tetracyclines
Doxycycline, Tetracycline, Minocycline
Fluroquinolones moa
Inhibit DNA gyrase and topoisomerase IV
First generation Fluroquinolones, example and coverage
Nalidixic Acid : • Limited to Gram-negative bacteria
uncomplicated urinary tract infections (UTIs)
2nd generation Fluroquinolones, example and coverage
Ciprofloxacin,
Ofloxacin
Coverage •Broad Gram-negative, including Pseudomonas; limited Gram-positive and atypical coverage
3rd generation Fluroquinolones, example and coverage
Example: Levofloxacin
Enhanced Gram-positive (including Streptococcus pneumoniae), moderate Gram-negative, atypicals
4th generation Fluroquinolones
Example: Moxifloxacin
Gram-positive (including Streptococcus pneumoniae), anaerobes,
atypicals; weaker Gram-negative
bacterial conjunctivitis
Best uses of Ciprofloxacin
UTIs,
GI infections,
anthrax,
bone/joint infections
Best use of Levofloxacin
Community-acquired pneumonia,
skin infections,
UTIs
Side effects of Fluroquinolones
Tendonitis and tendon rupture (Black Box Warning) mostly in children
• QT prolongation (risk of arrhythmias, especially with Moxifloxacin)
• CNS effects: Confusion, hallucinations (more common in elderly)
• Phototoxicity
Aminoglycosides SE
- Nephrotoxicity (dose-dependent),
ototoxicity (hearing loss, tinnitus, vertigo)
Neuromuscular blockade (in patients with pre-existing muscle conditions or when combined with certain anesthetics) serious
Common SE of vancomycin
Red man syndrome (flushing due to rapid infusion), nephrotoxicity
Metronidazole SE
Peripheral neuropathy (with prolonged use), seizures
Disulfiram-like reaction when taken with alcohol (flushing,
vomiting, headache)
Sodium Nitroprusside moa
Dilates bot venous and arterial vessels
Hydralazine moa
Direct vasodilator at the arterial smoth muscles reducing total peripheral resistance
Hydralazine is CI in ? Why?
CAD, because the reflexes tachycardia causes an increase in myocardial oxygen demand worsening ischemia
