initial therapy - mc microb - antib Flashcards
Meningitis, bacterial,
community-acquired
Streptococcus pneumoniae
(pneumococcus),1 Neisseria
meningitidis
(meningococcus)
Cefotaxime,2 2–3 g intravenously every 6 hours or ceftriaxone, 2 g
intravenously every 12 hours; plus vancomycin, 15 mg/kg intravenously
every 8 hours
Meningitis, bacterial, age > 50,
community-acquired
Pneumococcus, meningococcus,
Listeria monocytogenes,3
gram-negative bacilli, group B
streptococcus
Ampicillin, 2 g intravenously every 4 hours, plus cefotaxime, 2–3 g
intravenously every 6 hours or ceftriaxone, 2 g intravenously
every 12 hours, plus vancomycin, 15 mg/kg intravenously every
8 hours
Meningitis, postoperative
(or posttraumatic)4
S aureus, gram-negative bacilli, coagulase-negative staphylococci, diphtheroids (eg, Propionibacterium acnes) (uncommon) pneumococcus (in posttraumatic) Vancomycin4, 15 mg/kg intravenously every 8 hours, plus cefepime, 3 g intravenously every 8 hours
Brain abscess Mixed anaerobes, pneumococci,
streptococci
Penicillin G, 4 million units intravenously every 4 hours, plus metronidazole,
500 mg orally every 8 hours; or cefotaxime, 2–3 g intravenously
every 6 hours or ceftriaxone, 2 g intravenously every
12 hours plus metronidazole, 500 mg orally every 8 hours
Pneumonia, acute, communityacquired,
non-ICU hospital
admission
Pneumococci, M pneumoniae,
Legionella, C pneumoniae
Cefotaxime, 2 g intravenously every 8 hours (or ceftriaxone, 1 g
intravenously every 24 hours or ampicillin 2 g intravenously every
6 hours) plus azithromycin 500 mg intravenously every 24 hours;
or a fluoroquinolone5 alone
Endocarditis, acute (including
injection drug user)
S aureus, E faecalis, gram-negative aerobic bacteria, viridans streptococci Vancomycin, 15 mg/kg intravenously every 12 hours, plus gentamicin, 1 mg/kg every 8 hours
Septic thrombophlebitis eg, IV tubing, IV shunts)
S aureus, gram-negative aerobic
bacteria
Vancomycin, 15 mg/kg intravenously every 12 hours, plus ceftriaxone,
1 g intravenously every 24 hours
Osteomyelitis
S aureus Nafcillin, 2 g intravenously every 4 hours; or cefazolin, 2 g intravenously
every 8 hours
Septic arthritis
S aureus, N gonorrhoeae Ceftriaxone, 1–2 g intravenously every 24 hours
Pyelonephritis with flank pain and
fever (recurrent urinary tract
infection
E coli, Klebsiella, Enterobacter,
Pseudomonas
Ceftriaxone, 1 g intravenously every 24 hours; or ciprofloxacin,
400 mg intravenously every 12 hours (500 mg orally); or levofloxacin,
500 mg once daily (intravenously/orally)
Fever in neutropenic patient
receiving cancer chemotherapy
S aureus, Pseudomonas, Klebsiella, E coli Ceftazidime, 2 g intravenously every 8 hours; or cefepime, 2 g intravenously every 8 hours
Intra-abdominal sepsis (eg, postoperative,
peritonitis,
cholecystitis)
Gram-negative bacteria, Bacteroides, anaerobic bacteria, streptococci, clostridia Piperacillin-tazobactam, 4.5 g intravenously every 6 hours, or ertapenem, 1 g every 24 hours
Erysipelas, impetigo,
cellulitis,
ascending
lymphangitis
Group A streptococcus Phenoxymethyl penicillin,
0.5 g orally four times daily
for 7–10 days
Cephalexin, 0.5 g orally four times daily for
7–10 days; or azithromycin, 500 mg on
day 1 and 250 mg on days 2–5
Furuncle with
surrounding
cellulitis
Staphylococcus aureus Dicloxacillin, 0.5 g orally four times daily for 7–10 days for MSSA. However, in many areas of the United States, CA-MRSA has become predominant; TMP-SMZ two double-strength tablets twice daily for 7–10 days; or clindamycin 0.3 g orally four times daily for 7–10 days Cephalexin, 0.5 g orally four times daily for 7–10 days for MSSA. For CA-MRSA, tetracyclines, but not fluoroquinolones, are reasonable alternatives
Pharyngitis
Group A streptococcus Phenoxymethyl penicillin, 0.5 g
orally four times daily, or amoxicillin,
0.5–1 g orally three times
daily, for 10 days
For patients with history of non-anaphylactic
penicillin allergy, cephalexin, 0.5 g orally
four times daily for 10 days; for patients
with more severe penicillin allergy,
clindamycin, 300 mg orally four times
daily for 10 days; or azithromycin, 500 mg
on day 1 and 250 mg on days 2–5; or clarithromycin
or azithromycin for susceptible
isolates
Otitis media
Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis Amoxicillin, 0.5–1 g orally three times daily for 10 days Augmentin,2 0.875 g orally twice daily; or cefuroxime, 0.5 g orally twice daily; or cefpodoxime, 0.2–0.4 g daily; or doxycycline, 100 mg twice daily; or TMP-SMZ,1 one double-strength tablet twice daily (all regimens for 10 days)
Acute sinusitis
S pneumoniae, H influenzae, M catarrhalis Augmentin,2 0.875 g orally twice daily, For patients allergic to penicillin, doxycycline, 100 mg twice daily for 10 days, or some fluoroquinolones5 can be considered. Due to increasing resistance among pneumococci, monotherapy with a macrolide, a cephalosporin, or TMP-SMZ is not recommended
Aspiration
pneumonia
Mixed oropharyngeal flora, including anaerobes Clindamycin, 0.3 g orally four times daily for 10–14 days Phenoxymethyl penicillin, 0.5 g orally four times daily for 10–14 days
Pneumonia
S pneumoniae, Mycoplasma pneumoniae, Legionella pneumophila, Chlamydophila pneumoniae Doxycycline, 100 mg orally twice daily, or azithromycin (erythromycin, clarithromycin), 0.5 g orally on day 1 and 0.25 g on days 2–5 Amoxicillin, 0.5–1.0 g orally three times daily. Due to increasing resistance to doxycycline and macrolides among pneumococci, a fluoroquinolone5 for 10–14 days (or doxycycline plus amoxicillin)
Cystitis
Escherichia coli, Staphylococcus saprophyticus, Klebsiella pneumoniae, Proteus species, other gram-negative rods or enterococci Nitrofurantoin monohydrate macrocrystals 100 mg twice daily for 5–7 days (unless pregnant); fosfomycin 3 g orally as a single dose Cephalexin, 0.5 g orally four times daily for 7 days, for uncomplicated cystitis. Due to increasing resistance, TMP-SMZ and fluoroquinolones should not be used as first-line therapy for empiric treatment
Pyelonephritis
E coli, K pneumoniae, Proteus species, S saprophyticus Fluoroquinolones4 for 7 days if prevalence of resistance among uropathogens is
Gastroenteritis
Salmonella, Shigella,
Campylobacter,
Entamoeba histolytica
3The diagnosis should be confirmed by culture before therapy. Salmonella gastroenteritis does not require therapy. For susceptible Shigella
isolates, give ciprofloxacin, 0.5 g orally twice daily for 5 days; or TMP-SMZ double-strength tablets twice daily for 5 days; or ampicillin, 0.5 g
orally four times daily for 5 days. For Campylobacter infection, give azithromycin, 1 g orally times one dose, or ciprofloxacin, 0.5 g orally twice
daily for 5 days. For E histolytica infection, give metronidazole, 750 mg orally three times daily for 5–10 days, followed by diiodohydroxyquinoline,
600 mg orally three times daily for 3 weeks.
Urethritis,
epididymitis
Neisseria gonorrhoeae, Chlamydia trachomatis Ceftriaxone, 250 mg intramuscularly once plus azithromycin (or doxycycline) for N gonorrhoeae; azithromycin 1 g orally once, or doxycycline, 100 mg orally twice daily for 7 days, for C trachomatis Cefixime 400 mg orally once for N gonorrhoeae6
Pelvic inflammatory
disease
N gonorrhoeae, C trachomatis, anaerobes, gram-negative rods Levofloxacin 500 mg orally daily, or ofloxacin, 400 mg orally twice daily, for 14 days, plus metronidazole, 500 mg orally twice daily, for 14 days Cefoxitin, 2 g intramuscularly, with probenecid, 1 g orally, followed by doxycycline, 100 mg orally twice daily for 14 days; or ceftriaxone, 250 mg intramuscularly once, followed by doxycycline, 100 mg orally twice daily for 14 days
syphilis
Early syphilis (primary, secondary, or latent of 1 year’s duration or cardiovascular syphilis T pallidum Benzathine penicillin G, 2.4 million units intramuscularly once a week for 3 weeks (total: 7.2 million units) Doxycycline, 100 mg orally twice daily, for 4 weeks
Neurosyphilis T pallidum Aqueous penicillin G, 12–24 million
units/day intravenously
for 10–14 days
