Antibiotics Flashcards
Another name for penicillin
Beta-lactam antibiotics
Is penicillin bactericidal?
Yes, kills the bacteria
What is transpeptidase?
Enzyme that catalyzes linkage in peptidoglycan cell wall
How does penicillin work?
It binds to and competitively inhibits transpeptidase
What is needed for penicillin to be successful?
1) penetrate cell layers
2) keep beta lactam ring intact
3) bind to transpeptidase
Ways bacteria can become resistant to penicillin
1) gram negative adjust porin channel so penicillin can’t pass outer plasma membrane
2) beta lactamase cleaves bond in Batman lactam ring
3) alter transpeptidase so that antibiotic cannot bind
4) actively pump out beta lactam
What type of penicillins is MRSA resistant to?
All penicillins
What are the types of penicillins?
1) penicillin G
2) aminopenicillins
3) penicillinase- resistant penicillins
4) anti-pseudomonal penicillins
5) cepalosporins
6) carbapenems
what antibiotics are included in antipseudomonal penicillins
Carboxypenicillins
Ureidiopenicillins
Monobactams
Basic description of cephalosporins
- Beta lactam ring
- Resistant to beta lactamase
- Cover broad spectrum of gram positive and gram negative
Broadest spectrum beta lactam antibiotics
Carbapenems
What is penicillin G commonly used for?
Strep pneumo
Strep throat
What are the aminopenicillins?
Ampicillin and amoxicillin
What are ampicillin and amoxycillin best for?
One of few drugs effective against enterococcus
Listeria
Otitis media
Bronchitis
Sinusitis
What is amp-gent and what is it typically used for?
Ampicillin - gentamicin
More serious utis
Penicillinase resistant penicillins
Methecilin, nafacillin, oxacillin
Cloxacillin, dicloxacillin
What are penicillinase resistant penicillins best for?
Staph (other than MRSA) and gram positive skin infections
What are the antipseudomonal penicillins?
Carboxypenicillins and ureidopenicillins
What do the antipseudomonal penicillins work to trat?
Gram negatives, esp pseudomonas aeruginosa
Anaerobes
Examples of antipseudomonal penicillins
Ticarcillin, carbenicillin
Piperacillin, mezlocillin
What are beta lactamase inhibitors? Examples given in combo with other penicillins?
Inhibit beta lactamase
Examples:
1. Clavulanic acid (augmentin is amoxycilin + clavulanic acid)
2. Sulbactam (unasyn is ampicillin and sulbactam)
3. Tazobactam- zosy -Piperacillin and tazobactm
What organisms are resistant to cephalosporins?
- MRSA
- Enterococcus
Ceohalosporiniase producing organisms
Describe first generation ceohalosporins
Most effective against gram positive
Most have -ph in name
Cephalothib
Cephaprin
Cephradine
Ceophalexib
Exception cefazolin
Cefadroxil
Describe second gen cephalosporin
Okay at treating gram positives and gram negatives
Fam, fa, fur, fox, or tea in name
Cefamandole
Cefaclor
Cefuroxime
Cefoxitin
Cefotetan
Describe third generation cephalosporins
Beta lactam drugs
Better at treating gram negatives
T in name
Ceftriaxone
Ceftazidime
Cefotaxime
Ceftibuten
Describe fourth generation ceohalosporin
Great gram negative coverage and good gram positive coverage
Beta lactam ring
Cefeopime
How many generations of cephalosporins are there?
5
What antibiotics are often given as prophy before surgery?
First gen cephalosporins
Use for first generation cephalosporins
Pre surgery prophy
What are second generation cephalosporins typically used for?
Otitis media
Sinusitis
Anaerobic gut bacteria
Prophy GI tract surgery
What are the carbepenems?
Imipenem
Meropenem
Doripenem
Ertapenem
What are third generation cephalosporins used for?
Community acquired pneumonia, meningitis,pyelonephritis, meningitis, pseudomonas
Describe carbapenems
-Beta lactam antibiotics
-Resistant tibeta- lactamase (including EBSL)
-broadest antibacterial activity of any anyibiotic
What antibiotic is a monobactams?
Aztreonam
Describe monobactam
- gram negative, aeerobic (only)
- beta lactam ring
What are monobactams used for?
- Hospital acquired aerobic gram negatives (ex pseudomonas)
- used in combo with antibiotics that kill gram positives
What are the anti-ribosomal antibiotics
CLEAN TAG
C- choloramphenicol and clindamycin
L- linezoid
E- erythromycin
T- tetracycline and tigecycline
AG- aminoglycosides
What conditions does clindamycin cover
Anaerobes
Bacterial vaginosis
Toxic shock syndrome from GAS or staph
Lung abscess
What is the concern with clindamycin?
Can cause c. Diff, but most c. Diff cases from penicillins
What are linezoid and tedizolos used for
Resistant bugs (MRSA, VRE
HAP
What are the macrolides?
Erythromycin, azithromycin, clarithromycin, telithromycin
What are macrolides typically used for?
-Atypical and community acquired pneumonia
- upper respiratory infections
What is doxy used for?
- chlamydia
- walking pneumonia due to mycoplasma pneumonia
- brucellosis
- rickettsial diseases
- acne
- anthrax
Describe aminoglycosides
-Kill aerobic gram-negative enteric organisms
- usually paired with penicillin to help pass through cell wall
Rule to remember which antibiotics are aminoglycosides?
- like macrolides they end in -mycin (streptomycin, gentamicin…etc
- amikacin
What are the first line drugs for TB
Isoniazid*
Rifampin*
Pyrazinamide
Ethambutol
Streptomycin
Treatment for active TB
6 months rifampin regimen
- 4 drugs 2 months, then 2 drugs 4 months (second phase rifampin and isoniazid increases to 7 months of sputum culture still positive after first 2 months)
Treatment for latent TB
9 months isoniazid
4 months rifampin
Complication for TB treatment
Hepatotixicity
Treat the following patients if the PPD is >= 5 mm
- Persons with HIV infection
- Persons with fibrotic changes in chest x-ray compatible with old healed tuberculosis
- Close contacts of persons with newly diagnosed active tuberculosis
- Patience with organ transplants and other immunosuppressed patients
Treeat the following moderate risk patients if PPD is greater than 10 mm
- Persons with medical conditions that lower the immune system, like diabetes, prolonged steroid or immunosuppressive treatment, renal failure, and others
- Recent arrivals within the past 5 years from countries with a high prevalence of tuberculosis
- Persons who inject drugs
- Residence and employees of high risk settings, so just homeless shelters, long-term care facilities, prisons, and other healthcare facilities
- Recent PPD conversions within a two year period
- Healthcare workers
What method of medication administration is required for tuberculosis
Direct observation therapy
Describe fluoroquinolone
- oral
- penetrate tissues well
- inhibit DNA gyrase
- high drug level in target tissue
What is the common ending of all fluoroquinolones
-floxacin
Example- ciprofloxacin
What are fluoroquinolones (cipro) best for?
Gram negatives (pseudomonas, enterics, complicated UTIs, facultative intracellular pathogens (because concentrated in cells)
Describe vancomycin
-Covers all gram positives
-Inhibits peptidoglycan production
-IV most of the time (not absorbed orally) oral for c. Diff
- increasing resistance
What are the glycopeptide antibiotics?
- vancomycin
- telavancin
- dalbavancin
- orotavancin
Newer antibiotic that kills gram positive bacteria, including VRE
Daptomycin
Antimetabolite antibiotics that act synergistically to kill many gram positive and gram negative bacteria by inhibiting TH4 production
Trimethoprim and sulfamethoxazole
What is the sulfa drug tmp-smp primarily used for?
Gram positive and gram negative aerobes
UTIs
Respiratory illness
Enterics
Preventative for Pneumocystis jirovechii when CD4 counts below 200
