Good For Flashcards
Natural Penicillins
Penicillin G, V
Good for
Syphilis
- particularly neurosyphilis
- penicillin G is drug of choice
Susceptible streptococcal infections
- pharyngitis
- endocarditis
Antistaphylococcal Penicillins Good for
Infections caused by MSSA
- endocarditis
- skin/soft-tissue infections
Aminopenicillins
Amoxicillin, Ampicillin
Good for
Ampicillin is drug of choice for susceptible Enterococci:
- E. faecalis (almost always susceptible)
- E. faecium (often resistant)
Any beta-lactam has to be combined with an aminoglycoside to achieve bactericidal activity against Enterococci
-should be done in serious infections like endocarditis
Alternative regimen for UTIs in pregnant women because eliminated renally
- category B
- resistance to E. coli very high (perform susceptibility testing)
- always perform follow-up cultures (asymptomatic bacteruria dangerous for pregnant women)
Infections caused by susceptible:
- GNRs
- Enterococci
- Streptococci
Used infrequently in complicated nosocomial infections
-resistance among GNRs is prevalent
Amoxicillin frequently prescribed for infections of upper respiratory tract:
- Streptococcal pharyngitis (strep throat)
- Otitis media (ear infection)
Penicillin/BL-inhibitor Combos
Good For
Empiric therapy of nosocomial infections
-particularly nosocomial pneumonia (not aminopenicillin combinations)
Have activity against aerobes and anaerobes so good empiric choice for mixed infections
- intra-abdominal infections
- diabetic ulcers
- aspiration pneumonia
Amoxicillin/Clavulanate
- upper and lower respiratory tract infections (when BL-producing organisms found/suspected)
- useful for UTIs (when resistance to other drugs seen; should not be given for a short 3 day course as with FQ or SMX/TMP
Sulbactam
- useful activity against A. baumannii (highly resistant GNR that causes nosocomial infections)
- high doses of ampicillin/sulbactam can be used
1G Cephalosporins
Good For
Skin and skin structure infections Surgical prophylaxis -most common indication in the hospital -no more than 1 dose Staphylococcal bloodstream infections Osteomyelitis Endocarditis -caused by MSSA
Should not be used in CNS infections
- may not cross the BBB
- Antistaphylococcal penicillins do cross BBB
2G Cephalosporins
Good For
Upper respiratory tract infections
Community acquired pneumonia
Gonorrhea
Do not cross the BBB
Cephamycins
- cefmetazole, cefotetan, cefoxitin
- active against many anaerobes in GI tract
- often used for surgical prophylaxis in abdominal surgery
- resistance increasing in B. fragilis group infections (limit duration after surgery; if infection develops, use BL-inhibitor combination or Gram negative agent + Metronidazole)
3G Cephalosporins
Good For
Lower respiratory tract infections Pyelonephritis Nosocomial infections -ceftazidime Lyme disease -ceftriaxone Meningitis Gonnorhea Skin and skin structure infections Febrile neutropenia -ceftazidime
Useful for treatment of CNS infections
- ceftriaxone, cefotaxime, ceftazidime cross the BBB
- ceftazidime poor choice for community acquired meningitis (S. pneumoniae predominates)
Gonorrhea
- ceftriaxone is drug of choice
- 250mg IM one time dose
- should receive azithromycin also (empiric therapy for chlamydia and may reduce emergence of ceftriaxone resistance)
Ceftriaxone
- effective for UTIs (has dual elimination: renal (does not need to be adjusted for renal dysfunction) and biliary)
- higher doses for MSSA (2-4 grams per day), particularly invasive infections
- once daily except for meningitis (2g IV q12H) and vancomycin +/- ampicillin
4G Cephalosporins
Cefepime
Good For
Febrile neutropenia
Nosocomial pneumonia
Postneurosurgical meningitis
Other nosocomial infections
Although indicated for UTIs and LRTIs, it is overkill for most community acquired sources of these infections
Ceftaroline
Good for
Approved for:
- complicated skin and soft tissue infections
- community acquired pneumonia
Successful in case series and retrospective studies for:
- bloodstream infections
- endocarditis
- meningitis
- osteomyelitis
- hospital acquired pneumonia
Cephalosporins/BL-inhibitor combinations
Good For
Both: Multidrug resistant Pseudomonas infections Mixed aerobic/anaerobic infections ESBL producing organisms Intra-abdominal infections
Ceftazidime/avibactam:
Carbapenem resistant Enterobacteriaceae infections
Avibactam has novel MOA
-works against many beta lactamases produced by K. pneumoniae and P. aeruginosa
Ceftolozane is 3G cephalosporin
-evades many resistance mechanisms of P. aeruginosa
Only ceftazidime/avibactam active against carbapenem resistant Klebsiella and other enteric GNRs
Substantial resistance to these agents among gut anaerobes (unlike penicillin based BL combinations)
-add metronidazole
Carbapenems
All
Good For
Mixed aerobic/anaerobic infections
ESBL producing organisms
Intra-abdominal infections
Carbapenems
Imipenem, Doripenem, Meropenem
Good For
Nosocomial pneumonia
Febrile neutropenia
Other nosocomial infections
Monobactams
Aztreonam
Good for
Gram- infections
-including Pseudomonas
Useful in patients with history of beta lactam allergy
- except patients who have specific allergy to ceftazidime
- ceftolozane also shares this side chain
Shares virtually same spectrum as ceftazidime
Can be administered via inhalation to prevent exacerbations of cystic fibrosis
Glycopeptides
and Short Acting Lipoglycopeptides
Vancomycin
Good for
Drug of choice for MRSA
-also empiric use when MRSA is concern (ex: nosocomial pneumonia)
Other Gram+ infections when patient has severe beta lactam allergy
Oral form
- absorbed very poorly
- only for C. difficile associated disease
- IV form does not reach high enough intracolonic concentrations to kill C. difficile
Does not kill MSSA as quickly as beta lactams
-use cefazolin or nafcillin instead
Glycopeptides
and Short Acting Lipoglycopeptides
Telavancin
Good for
Indicated for:
Skin and skin structure infections
Hospital acquired pneumonia
More rapidly bactericidal than vancomycin
-clinical evidence showing this as a benefit is currently lacking
Long Acting Glycopeptides
Dalbavancin, Oritavancin
Good For
Skin and skin structure infections
-Gram+ organism either known or highly suspected
Dosing:
Dalbavancin
-1000mg on day 1 then 500mg a week later
or
-1500mg once
Fluoroquinolones
Usage
Antipseudomonal doses Ciprofloxacin: -400mg IV q8h or -750mg PO q12h
Levofloxacin:
750mg IV/PO daily
Most FQ cleared renally and require dose reduction in renal dysfunction
- moxifloxacin not excreted into urine (not approved for UTIs)
- gemifloxacin has dual elimination (UTI usage not established; does require dose adjustment in renal failure)
Risks outweigh benefits for most cases of sinusitis, bronchitis, and uncomplicated UTIs unless other options not available due to rare but serious side effects
Fluoroquinolones
Ciprofloxacin
Indications
CAP, sinusitis, AECB: - UTI: + Intra-abdominal infection: + Systemic Gram- infections: + Skin/soft tissue infection: - Pseudomonas (+/- beta lactam): + Treatment/prophylaxis in bioterrorism scenario (active vs anthrax, plague, tularemia): +
Fluoroquinolones
Levofloxacin
Indications
CAP, sinusitis, AECB: + UTI: + Intra-abdominal infection: + Systemic Gram- infections: + Skin/soft tissue infection: + Pseudomonas (+/- beta lactam): + Treatment/prophylaxis in bioterrorism scenario (active vs anthrax, plague, tularemia): +
Fluoroquinolones
Moxifloxacin
Indications
CAP, sinusitis, AECB: + UTI: - Intra-abdominal infection: + Systemic Gram- infections: + Skin/soft tissue infection: + Pseudomonas (+/- beta lactam): - Treatment/prophylaxis in bioterrorism scenario (active vs anthrax, plague, tularemia): ?
Fluoroquinolones
Gemifloxacin
Indications
CAP, sinusitis, AECB: + UTI: ? Intra-abdominal infection: ? Systemic Gram- infections: ? Skin/soft tissue infection: + Pseudomonas (+/- beta lactam): - Treatment/prophylaxis in bioterrorism scenario (active vs anthrax, plague, tularemia): ?
Aminoglycosides
Usage
Relatively poor distribution to many tissues (including lungs and CNS)
-less than optimal as monotherapy for many severe infections
Base dose on ideal or adjusted body weight rather than total body weight
Differences in activity:
For Pseudomonas:
amikacin > tobramycin > gentamicin
For Klebsiella:
amikacin = gentamicin > tobramycin
Streptomycin has limited uses:
Enterococcus
Tuberculosis
Plague
Aminoglycosides
Good for
In combination with a beta lactam: Serious infections with documented or suspected Gram- pathogens -febrile neutropenia -sepsis -exacerbations of cystic fibrosis -ventilator associated pneumonia
Primarily gentamicin also used in combination with a beta lactam or glycopeptide for serious Gram+ infections
- endocarditis
- osteomyelitis
- sepsis
Streptomycin and Amikacin
-in combination with other antimycobacterial sided for drug resistant infections with Mycobacterium tuberculosis or other mycobacteria
Tetracyclines
Doxy/Mino/Tetracycline
Good for
Uncomplicated respiratory tract infections
- useful but not highly studied alternatives
- acute exacerbations of chronic bronchitis
- sinusitis
- community acquired pneumonia
Drugs of choice for many tick-borne diseases
Alternative for:
- skin or soft tissue infections
- syphilis
- pelvic inflammatory disease (with cefoxitin)
Alternative to ciprofloxacin in bioterrorism scenarios
- anthrax
- plague
- tularemia
Malaria
-prophylaxis and treatment
Doxycycline preferred in most situations over minocycline or tetracycline
Tetracycline eliminated renally
-should not be used in cases of renal insufficiency (can worsen renal dysfunction)
Doxycycline does not need to be adjusted in renal or hepatic dysfunction
Glycylcyclines
Tigecycline
Good for
May have a role in treatment of complicated polymicrobial infections
- intra-abdominal infections
- complicated skin and skin structure infections
Very large volume of distribution
- distributes highly into many tissues
- leads to low bloodstream concentrations (not ideal for treating primary bloodstream infections
Should not be used for UTIs
- eliminated hepatically
- achieves low urinary concentrations
Macrolides and Ketolides
Good for
Upper and lower respiratory tract infections Chlamydia Atypical mycobacterial infections Traveler's diarrhea -azithromycin
Macrolides are bacteriostatic drugs (should not be used when cidal activity is usually required
- meningitis
- endocarditis
- etc.
H. pylori induced GI ulcer disease
-Prevpac contains clarithromycin, lansoprazole, and amoxicillin
Their spectrum makes them ideal choice for community acquired pneumonia
-high resistance rate to S. pneumoniae makes them risky choices as monotherapy for infection worse than mild (treat with something else or add beta lactam active against S. pneumoniae)
Erythromycin used as prokinetic agent for impaired GI motility (GI stimulant)
Oxazolidinones
Linezolid, Tedizolid
Good for
Resistant Gram+ organisms
- MRSA
- VRE
Linezolid:
- pneumonia
- skin and skin structure infections
- UTIs
- other uses
Tedizolid:
- only indicated for skin and skin structure infections (studied as a 6 day therapy; comparable to 10 days of linezolid)
- may be useful for other types
Linezolid has dual hepatic and renal elimination
-do not need to adjust dose for renal or hepatic dysfunction
Tedizolid eliminated primarily by liver
-may not sufficiently concentrate in urine to treat UTIs
Nitroimidazoles
Metronidazole
Good for
Documented or suspected abdominal anaerobic bacteria
-add second drug for aerobic coverage if necessary
Vaginal trichomoniasis
GI infection caused by susceptible protozoa
- amebiasis
- giardiasis
- etc.
Is a component of therapy for H. pylori GI ulcer disease in combination
C. difficile
-mild to moderate disease
Metronidazole has ~100% bioavailability
-switch from IV to PO when possible
Tinidazole
- spectrum similar to metronidazole
- approved only for parasitic infections
Nitrofurans (nitrofurantoin)
and Fosfomycin
Good for
Uncomplicated cystitis
- only for infections of lower urinary tract
- in patients who have significant renal dysfunction (CrCL < 50mL/min), there may be insufficient accumulation of the drug in the urine for activity
Prophylaxis against recurrent uncomplicated lower UTI
-nitrofurantoin
Nitrofurantoin
-can be used for 5 days instead of traditional 7 day regimen
Fosfomycin
-single dose
Ineffective for infections outside of lower urinary tract
- only reach high concentrations in the urine due to PK limitations
- should not be used for more severe UTIs like pyelonephritis and urosepsis
Retain excellent activity against E. coli
>90% in most studies
-have adequate coverage of other common community acquired urinary tract pathogens
Streptogramins
Quinupristin/Dalfopristin
Good for
MRSA or E. faecium
-in patients not responding to or intolerant of other medications
E. faecalis is more common in most hospitals
- less likely to be VRE
- only use if species is known (linezolid and daptomycin do not have this issue)
No longer considered 1st line for VRE
-the indication was removed from labeling due to lack of follow up data after the initial approval
Must be mixed with D5W
-becomes insoluble and can crystallize when given with NS
Cyclic Lipopeptides
Daptomycin
Good for
Skin and skin structure infections -caused by resistant Gram+ organisms Staphylococcal bacteremia -including right sided endocarditis (few antibiotics have this indication) Enterococcal bacteremia -not indicated or as well studied
Cannot be used for pneumonia
- binds to human pulmonary surfactant (renders drug inactive)
- however it does penetrate lung tissue well
FDA approved dosing is 4-6mg/kg/day
- studies show higher doses may be more effective without causing substantially more toxicity
- may see up to 12mg/kg/day for difficult to treat infections
Folate Antagonists
Trimethoprim/Sulfamethoxazole
Good for
Uncomplicated lower UTIs -empirically only in areas with low resistance Prophylaxis against recurrent UTIs Listeria meningitis P. jirovecii pneumonia -treatment and prophylaxis Toxoplasma encephalitis
Alternative for: Bacterial prostatitis Typhoid fever MRSA -predominant outpatient strain likes to cause skin infections with often large abscesses (must drain abscess)
Used to be first line for acute uncomplicated cystitis in women
-in areas with E. coli resistance greater than 15-20%, use alternative (nitrofurantoin); in these cases at least don’t use as empiric therapy for complicated UTI (pyelonephritis or urosepsis)
TMP/SMX has excellent oral bioavailability
Fairly insoluble in IV solutions; relatively large volumes of diluent needed for it to go into solution
Other drugs in class used against parasitic/fungal infections: Dapsone Pyrimethamine Sulfafoxine Sulfadiazine -toxoplasmosis
Lincosamides
Clindamycin
Good for
Skin and soft tissue infections Infections of oral cavity Anaerobic intraabdominal infections Acne -applied topically P. jirovecii pneumonia -used second line -in combination with primaquine Malaria -in combination with other drugs Bacterial vaginosis Bacterial endocarditis -prophylaxis
Consider it a mix of vancomycin + metronidazole
- an alternative for Gram+ infections (such as beta lactam allergy)
- more variable activity against MRSA (more community acquired strains are susceptible to TMP/SMX than to clindamycin) and S. pyogenes
- higher level of resistance among Gram- anaerobes (B. fragilis)
- best used empirically for nonsevere infections of skin and oral cavity; or definitive therapy when susceptibilities known
Reasonable alternative for staphylococcal infections
-organisms that are clindamycin susceptible but erythromycin resistant harbor a gene that may lead to high level clindamycin resistance during therapy (these strains should be screened with a D-test: if positive, inducible clindamycin resistance is present)
Useful in necrotizing fasciitis and other toxin mediated diseases
- due to inhibition of protein synthesis and activity against organisms in stationary phase growth
- consider adding it onto beta lactam based therapy for these infections
Nearly 100% bioavailable
-oral doses usually lower than IV to improve GI tolerance
Polymixins
Colistin (colistimethate sodium); polymixin B
Good for
Multidrug resistant Gram- infections (poorly studied; other drugs should be used if pathogens susceptible)
- pneumonia
- bacteremia
- sepsis
- complicated UTIs
Give both drugs with loading dose
Polymixin B given in active form
- has more predictable PK
- not eliminated renally; should not be dose adjusted in renal dysfunction (unlikely successful in treating UTIs)
- 1mg = 10,000 units
Colistin given as renally eliminated prodrug
- colistimethate sodium converted to active colistin in the body
- 400mg colistimethate = 150mg colistin base activity
- European countries dose in international units (1mg CBA = 33,333 units rounded to 30,000); (1,000,000 IU = 80mg colistimethate = 30mg CBA); (1mg CBA = 2.7mg colistimethate = 30,000 units)
Oral form of colistin only for bowel decontamination
-such as before GI surgery
Aerosolized forms used to decrease colonization with Gram- bacteria (mainly Pseudomonas) in some patients
- especially in cystic fibrosis
- prepare just before administration
- some experts have used for pneumonia (not very strong evidence)
Fidaxomicin
Good for
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