Antibiotics Flashcards
The gram positive bacterias usually end in US, OC, ER and UM (sound masculin) except which one?
- Listeria spp
- Nocardia spp
- Gemella spp
Gram negative bacterias usually end in A or ER except which one?
- Proteus spp
- Haemophilus spp
- Acinetobacter spp
- Bacteroides spp
- Vibrio spp
Which b-lactams cross the BBB appreciably?
–Penicillin IV (high dose)
–Ampicillin IV (high dose)
–Third generation cephalosporins IV (high dose)
–Cefepime
–Carbapenems
Adverse reactions of All b-lactams?
–GI upset
–Diarrhea (b-lactamase inhibitors; cefixime/Suprax)
–Drug induced neutropenia
–Seizures
–Anaphylaxis
Why are Carbapenems used?
BROAD SPECTRUM: Like BROAD SPECTRUM b-lactams/b-lactamase inhibitor combinations
- Gram-positives (MSSA), gram-negative, anaerobes
- Usually resistant to b-lactamases
Do Cephalosporins work against Gram-positive Enterococcus spp / Listeria spp?
Non
Which generation of Cephalosporins works againts gram-negative Pseudomonas spp / Campylobacter spp?
3rd (Only ceftazidime) and 4th
Penicillins and b-lactamase inhibitors are used against what bacteria?
- S. aureus
- Most gram-positive organisms including Enterococcus and Listeria spp
- Most gram-negative respiratory pathogens (Haemophilus and Moraxella spp)
- Most gram-negative enteric bacteria
- Most anaerobes (gram-positive and gram-negative)
What can you use against Pseudomonas spp?
Timentin and Pip/tazo (Penicillins and b-lactamase inhibitors)
S. aureus choice of antibiotic?
Cloxacillin
E Coli choice of antibiotic?
Ampicillin IV
Pseudomonas aeruginosa choice of antibiotic?
–Ticarcillin
–Piperacillin
Which type of antibiotic is time dependant?
- Beta-lactam group (Penicillins and their derivatives)
- Macrolides and ketolides
Type of antibiotic that is concentration dependant?
aminoglycosides
Which antibiotics have such good bioavailability that po = IV availability?
–Clindamycin po = IV
–Fluoroquinolones po = IV
–Septra po = IV
–Tetracyclines po = IV
–Metronidazole po = IV
–Linezolid po = IV
LIMITED BY GI TOLERANCE AND ABSORPTION
Which b-lactams have activity against MSSA?
–Cloxacillin po/IV (and methicillin)
– b-lactam/b-lactamase combinations (po/IV)
–1st and 2nd generation cephalosporins po/IV
•3rd generation IV NOT that good – just OK
–Cefepime
–Carbapenems
Which b-lactams have activity against Pseudomonas spp?
–Ticarcillin and Piperacillin (IV)
–Timentin and Pip/tazo (IV)
–Ceftazidime (IV)
–Cefepime (IV)
–Carbapenems (IV)
Which b-lactams have activity against anaerobes?
–Penicillin (po/IV)
–All b-lactam/b-lactamase combinations (po/IV)
–Carbapenems (IV)
What is the Antibacterial spectrum of Vancomycin?
Gram-positive including anaerobic gram-positive
Very good activity against Clostridium difficile (oral treatment)
Pharmacological key points of Vancomycin?
- BBB penetration, mainly with inflammation
- Need higher levels to penetrate BBB, bone and cartilage, heart tissue
- Need higher levels when dealing with MRSA
Adverse reactions of Vancomycin?
Nephrotoxicity: Usually with accumulation (high trough levels)
When administered over short period (<1 hr): Histamine release (Red-man syndrome)
What is the antibacterial spectrum of Macrolides/Ketolides?
Gram-positives
- S. pneumoniae (if S)
- Group A Streptococcus (if S)
Gram-negatives
- Campylobacter spp
- Bordetella pertussis
Atypical bacteria
- Mycoplasma spp, Chlamydia spp, Clamydophila spp
Non-tuberculous mycobacteria
- Clarithromycin, azithromycin
Do macrolides cross the BBB?
Non
What is the Antibacterial spectrum of Aminoglycosides?
GRAM-NEGATIVE
Adverses effects of Aminoglycosides?
- Renal toxicity (high accumulated levels)
- Vestibular and cochlear toxicity (long period, irreversible)
- Muscular blockade (never give if NMD)
What are the 3 important types of Fluoroquinolones?
- Ciprofloxacin po/IV (Cipro)
- Levofloxacin po/IV (Levaquin): “The respiratory quinolone”
- Moxifloxacin po (Avelox)
What is the Antibacterial spectrum of Fluoroquinolones?
À PARTIR DE LA DEUXIÈME GÉNÉRATION
- S. pneumoniae
- MSSA
- Enteric gram negative rods
- Pseudomonas spp
- Atypicals
What is the Antibacterial spectrum of Sulfonamides?
Gram-positive and gram-negative:
- Enterobacteriaceae
- Shigella
- S.maltophilia (PARASITE)
- B.cepacia
- Chlamydia
- Nocardia
- Pneumocystis jeroveci
- Toxoplasma
** NOT ENTEROCOCCUS
What is the Antibacterial spectrum of Cyclines?
- Minocycline: topical for acne
- Tetracyclines: gram-negative enteric rods, anaerobes, atypical bacteria
- Tigecycline: gram-negative enteric rods, gram-positive, anaerobes, atypical
What is the mechanisms of action of Clindamycin?
- Inhibition of protein synthesis
- Bacteriostatic time-dependent activity
What is the Antibacterial spectrum of Clindamycin?
ONLY gram-positive:
- S.pneumoniae
- S aureus
What are the Adverse reactions of Clindamycin?
- May cause moderate diarrhea
- Associated with C.difficile colitis
What is the Antibacterial spectrum of Metronidazole (Flagyl)?
- ANAEROBES: vaginosis
- parasites
- anti-inflammatory in bowel
Why is used Rifamycins?
- TB
- Post-exposure prophylaxis:
- N. meningitides (meningitis and/or meningococcemia)
- H. influenzae (meningitis)
What is the adverse effect of Rifamycins?
- MAJOR drug interactions between Rifampin and Rifabutin: both are metabolized in the liver and induce CYP-450 enzymes
- Coloration of fluids
What is the antibiotic of choice for non-complicated cystitis treatment and UTI prophylaxis?
Nitrofurantoin
What are the antibiotics specifically used for multiresistant gram-positive bacteria?
- Oxazolidinones: Linezolid
- Streptogramins: Quinipristin/Dalfopristin
- Daptomycin
- Ceftaroline for MRSA
What are the adverse reaction sof Linezolid?
- Risk of thrombocytopenia
- Inhibitor of monoamine oxydase
What should absolutely be avoided when using Flagyl antibiotic?
ALCOHOL
What are the empiric antibiotics for a febrile neonate?
Ampicillin IV + Gentamicin IV
± third generation cephalosporin for meningitis (Cefotaxime IV)
What are the empiric antibiotics for a febrile baby (1-3 months old)
Ampicillin IV + Gentamicin IV
Ampicillin IV + Vancomycin IV + third generation cephalosporin for meningitis (Ceftriaxone IV)
What is the treatment of Cystitis UTI?
TMP/SMX (Septra) for 3 days
OR
Quinolone (Cipro) also for 3 days
What is the treatment of Pyelonephritis UTI?
Ampicillin (to cover possible enterococcus) and aminoglycoside (To cover gram negatives: Genta/Tobra)
Oral of IV depending of severity
What is the treatment of Gonorrhoeae?
Combination:
- Ceftriaxone (intra-muscular) x 1 dose, or Cefixime (by mouth) x 1 dose
- Azithromycin x 1 dose
What is the treatment of Chlamydia?
Azithromycin (oral) x 1 dose or doxycycline
What is the treatment of Trichomonas vaginalis (flagella)?
Metronidazole (Flagyl)
What is the treatment of Syphilis?
- Primary, Secondary or early latent: Penicillin IM x 1
- Late latent or latent of unknown duration; teritary: Penicillin IM weekly x 3 doses
- Neurosyphilis: Penicillin IV for 10-14 days
What is the antibiotic of choice against Enterococcus anaerobes?
Fluroquinolones 4th generation
Best treatment of endocarditis?
- Nafcillin (beta lactam)
- Aminoglycoside
Best treatment of endocarditis with prostethic valve infection?
- Nafcillin (beta lactam)
- Aminoglycoside
- Vancomycin
Treatment of choice of S. Aureus osteomyelitis?
Cloxacilin or Cefazolin
OR VANCOMYCIN IF METHICILLIN RESISTANT
