Recommended Treatments for Common Infections

Abbreviations and definitions
Augmentin	= Amoxacillin / clavulanate
Cotrimox	= co-trimoxazole = trimethoprim / sulfamethoxazole
H. Flu	= Haemophilus influenza
Unasyn	= Ampicillin/sulbactam
Zosyn	= piperacillin / tazobactam

Community Pneumonia Hospital Pneumonia Fungal Gastrointestinal Genitourinary

Skin/Soft Tissue Bone & Joint CNS Head and Neck STD

 

Community Acquired Pneumonia
Evaluation of community-acquired pneumonia (for details and addtional tests see ISDA Guidelines) Baseline assessment Chest x-ray to confirm diagnosis of pneumonia and assess severity of disease. For Ambulatory pts: Sputum Gram stain and culture may be useful. For Hospitalized pts Complete blood cell and differential counts Scr/BUN, glucose, electrolyte, and liver function indeces HIV serological status for pts aged 15-55 years Arterial blood gases and O2 for selected pts Blood cultures (×2; before the start of empiric antimicrobial therapy) Sputum Gram stain and culture. Acid-fast bacilli staining and culture in selected pts to test for Mycobacterium tuberculosis Test for Legionella in selected patients (seriously ill patients without an alternative diagnosis, especially if aged >40 years, immunocompromised, or nonresponsive to ß-lactam antibiotics, if clinical features are suggestive of this diagnosis, or in outbreak settings Thoracentesis for pleural fluid stain, culture, pH, and WBC count differential Antimicrobial therapy: When empiric therapy is deemed necessary, the choice of the antimicrobial agent is based on the severity of illness, the most likely pathogens, and the known resistance patterns of Strep pneumoniae, the most commonly implicated pathogen. When the pathogen involved is established, pathogen-specific antiinfective therapy should be started. The antiinfective agent chosen should be the most cost-effective, least toxic, and most narrow in antimicrobial spectrum.
Infection	Therapy	Comments
Unknown pathogen	Cefotaxime or ceftriaxone	If cephalosporin allergic, substitute erythromycin or clarithromycin
Influenza A	Ceftriaxone or ceftizoxime plus Amantidine or rimantidine
Mycoplasma or Chlamydia	Ceftriaxone or ceftizoxime plus Erythromycin or azithromycin
Legionella	Ceftriaxone or ceftizoxime plus Erythromycin	Substitute azithromycin if erythromycin not tolerated
See ISDA recommendations for the treatment of community-aquired pneumonia
Aspiration Pneumonia
G-negative, Anaerobes, and G-positive organisms	Cefotaxime plus Clindamycin or Zosyn or Unasyn
Hospital Acquired Pneumonia
G-negatives: E. coli, Enterobacter, Pseudomonas, and Klebsiella	Zosyn plus tobramycin or Clindamycin plus Ceftazidime or Imipenem with or without an aminoglycosides.	>60% of nosocomial pneumonias are G-negative in origin, 15% involve Staph
Staphylococcus aureus	Nafcillin	If MRSA suspected, add Vancomycin
Fungal Infections
Blastomycosis Histoplasmosis	Itraconazole for non-life threatening, non-meningeal infections Amphotericin B for serious infections	Itraconazole requires acid pH for absorption. Avoid antacids, H2 blockers, proton-pump inhibitors Amphotericin should be reserved for life threatening or CNS disease
Cryptococcus	Amphotericin B ± 5-Flucytocine	Ampho B is the agent of choice for rapidly progressing life-threatening disease Fluconazole is used for chronic suppression or prophylaxis in immunocompromised patients
Candida Albicans - superficial / mucosal	Fluconazole, Miconazole, Clotrimazole, and Ketoconazole	For candida esophagitis, fluconazole is the preferred agent
Candida albicans -deep seated / disseminated	Fluconazole or Amphotericin B	Amphotericin is the agent of choice for rapidly progressing life-threatening disease Prophylaxis with fluconazole in immunocompromised patients
Non-albicans candidiasis(Torulopsis glabrata, Candida krusei), deep seated, disseminated	Amphotericin B	Fluconazole is not very effective against these species
Candida lusetaniae	Fluconazole	Candida lusetaniae is resistant to Amphotericin
Gastrointestinal Infections
Cholecystitis Coliforms and enterococci	Cefotetan or Zosyn (or Unasyn) + Gentamicin	Cefotetan is used for mild-moderate infections
Cholangitis Enterics; Enterococci; Anaerobes	Zosyn (or Unasyn) + Gentamicin
Diverticulitis Enterics; Anaerobes	Cefotetan; Clindamycin + ofloxacin (or Ceftazidime); Zosyn (or Unasyn) + Gentamicin	Cefotetan is reserved for mild-moderate infections
Intra-abdominal peritonitis or abscess Enterics; Anaerobes; Enterococci	Zosyn (or Unasyn) + Gentamicin; Clindamycin + ofloxacin (or ceftazidime); Imipenem
Genitourinary Infections - UTIs
Cystitis E. coli; Staph aprophyticus	Cotrimox; Cephalexin; Nitrofurantoin	Infection may resolve spontaneously without abx or a three-day course may be sufficient
Pyelonephritis - Community Aquired / uncomplicated E. coli; Proteus	Cotrimox; Aminoglycosides; Ceftriaxone; Ofloxacin (oral)	Oral abx therapy is appropriate for mild-moderate cases Enterococcus is an uncommon
Pyelonephritis - Nosocomial (underlying GU disease) E. coli; Pseudomonas; Enterococcus	Ampicillin + gentamicin or tobramycin; Zosyn + Tobramycin; Ofloxacin ± ampicillin	These drug combinations are for empiric coverage for Pseudomonas and Enterococcus Septic patients require double G-negative coverage
Acute Prostatitis Patient <40 yrs Neisseria gonorrhea;  Chlamydia	Ceftriaxone 125 mg IM single dose or Ofloxacin 400 mg PO single dose + Doxycycline 100 mg PO bid x 7 days
Acute Prostatitis Patient >40 yrs Enterobacteraciae	Cotrimox or Ofloxacin
Chronic Prostatitis Enterobacteraciae; Enterococcus	Cotrimox for 3 months or Oflox for one month	rule out prostatic calculi in case of treatment failure
Skin/Soft tissue Infections
Cellulitis (non-diabetic) Streptococcus; Staphylococcus	Nafcillin or oxacillin (oral dicloxacilin)	Penicillin G is the drug of choice for known Streptococcal infection In case of PCN allergy, may use clindamycin or cefazolin ( if PCN allergy is mild).
Decubitus ulcer / Diabetic ulcer Staphylococcus; Streptococcus; Anaerobes; G-negative organisms	Augmentin or Unasyn; Clindamycin + Ofloxacin; Zosyn ± Tobramycin	Augmentin and Unasyn are ineffective against Pseudomonas Surgical consultation should be part of routine management
Necrotizing fasciitis Streptococcus; Staphylococcus; G-negative aerobes; Anaerobes	Penicillin + Clindamycin + Aminoglycoside (or Ofloxacin); Unasyn + Aminoglycoside (or Ofloxacin); Imipenem	Mixed flora, including anaerobes (clostridia perfringens) may be involved. Broad spectrum coverage is recommended. Primary emphasis is on surgical reatment
Human/animal bites Pasteurella multocida; Streptococcus; Staphylococcus	Unasyn or Augmentin	Spectrum includes Pasteurella multocida, especially in cat bites Do not use oral 1st-gen cephalosporins for Pasteurella
Bone & Joint Infections
Acute Osteomyelitis (hematogenous) Staphylococcus aureus; G-negatives (less frequent)	Nafcillin ± Aminoglycoside	Appropriate cultures are essential; G-negative osteomyelitis may be associated with underlying GI or UTI Ceftriaxone may allow outpatient parenteral therapy Cefazolin or clindamycin may be options for PCN allergic pts
Diabetic foot or contiguous ulcer G-negatives; G-positives; Anaerobes	Ofloxacin (PO) + Clindamycin or Zosyn / Unasyn + Aminoglycoside	Establish bacteriology with appropriate cultures whenever possible Adequate surgical debridement is critical to overall success
Chronic osteomyelitis	Establishing microbiology is extremely important
Septic Arthritis in the sexually active young adult Gonococcus	Ceftriaxone 125 mg IM in a single dose or Ofloxacin 400 mg po in a single dose plus Doxycycline 100 mg po bid X 7 days
Septic Arthritis in older adults Staphylococcus aureus Group A; Streptococcus; G-negative aerobes	Nafcillin + gentamicin or Nafcillin + PO Ofloxacin	Microbiology needed; Orthopedic consultation required
Septic Arthritis with prosthesis Staphylococcus epidermidis; Staphylococcus aureus; G-negatives	Vancomycin + 3rd gen cephalosporin	Orthopedic consultation required
CNS Infections
Meningitis
Community- Aquired Meningitis Age18-50 yrs Streptococcal pneumonia;  N. meningitis;  Haemophilus influenza (<5%)	Cefotaxime	3rd gen cephalosporins are empiric drug of choice due to concerns of moderately resistant pneumococcus Penicillin may be used if organism is penicillin-sensitive Antimicrobial therapy should be initiated within 30-60 min of presentation Penicillin-allergic patients should receive chloramphenicol
Community- Aquired Meningitis Age >50 or Alcoholic or Debilitated G-negative aerobes; Strep. pneum.; Listeria	Ampicillin + ceftriaxone
Post-surgical Meningitis Staphy epidermis; MRSA; G-negative aerobes	Vancomycin + Ceftazidime	Infected catheters should be removed
Meningitis in immunosuppressed host community- aquired pathogens; Listeria Monocytogenes; fungal; mycobacterial	Ampicillin + ceftriaxone	Initial Gram stain may provide clues for likely pathogen Need to rule out cryptococcus or other opportunistic infections
Viral Encephalitis / Meningioencephalitis Herpes simplex; Enteroviruses; Coxsackie	Acyclovir (for herpes) No therapy for the others	Early initiation of IV acyclovir is important for all patients suspected to have viral encephalitis Bacterial cerebritis expected if contiguous focus, ie., mastoiditis, sinusitis, otitis media Legionella or mycoplasma may present with encephalopathy
Encephalitis in immunosuppressed host
Herpes Simplex	Acyclovir	Need to rule out cryptococcus or toxoplasmosis before empiric therapy
Enteroviruses	No therapy
Coxsackie	No therapy
Cryptococcus	Amphotericin B
Toxoplasmosis	Pyrimethamine + sulfadiazine
Listeria	Ampicillin
Brain Abscess
Otogenic (temporal, parietal, cerebellar) Enterobacteraciae; Anaerobes; Strep. species	Ceftriaxone + metronidazole ± Penicillin G	If endocarditis (Staph aureus) is suspected, nafcillin should be used instead of Pen G.
Paranasal (frontal) Enterobacteraciae	Cefotaxime
Head and Neck Infections
Acute Sinusitis Strep. pneumoniae; H. influenza; Moraxella atarrhalis	Co-trimox; Cefpodoxime; Augmentin	Need to consider fungal etiology in certain patient populations (neutropenic, transplant, or IDDM)
Chronic Sinusitis Staph; Strep. pneumoniae; H. influenza; Moraxella atarrhalis; Anaerobes	Augmentin	Chronic sinusitis requires surgical drainage
Hospital-acquired Sinusitis Gram-negative aerobes; Staph. aureus; Anaerobes	See pneumonia treatment	Nasotracheal intubation and nasogastric tubes may increase risk of hospital-acquired sinusitis
Exudative Pharyngitis Group A strep	Penicillin G	Mononucleosis may present with exudative pharyngitis
Vesicular/Ulcerative Pharyngitis Coxsackie, Echo, or Herpes simplex virus	Acyclovir (for herpes simplex)
Membraneous Pharyngitis Mononucleosis; Diphtheriae	Erythromycin for Diphtheriae	Endotracheal intubation for maintenance of airway Steroids for impending airway obstruction There is no therapy for Mononucleosis
Epiglottitis Group A strep or Haemophilus influenza	Cefuroxime or ceftriaxone	Early elective endotracheal intubation
Periorbital/Orbital Cellulitis Strep species; Staph; Haemophilus influenza (adults); Anaerobes (if related to dental procedures)	Cefuroxime; Unasyn	R/O dental or sinus focus; If immunosuppressed, fungal etiology must be considered
Otitis media Strep. pneumoniae; H. influenza; Moraxella atarrhalis	Co-trimox; Cefpodoxime; Augmentin	Consider ENT pathology in adults with recurrent otitis media
Acute Mastoiditis Strep. pneumoniae; Strep. pyrogenes; Staph. aureus	Dicloxacillin; Cefuroxime	Surgery for abscess or osteomyelitis
Chronic Mastoiditis Polymicrobial, including Pseudomonas; Staph.aureus and anaerobes	Ceftazidime + Clindamycin;   Tobramycin + Zosyn	Surgery is required
Sexually Transmitted Diseases (STD )
Urethritis / Cervicitis / Prostatitis N. gonorrhaeae; Chlamydia	Ceftriaxone 125 mg IM single dose or Ofloxacin 400 mg PO single dose plus Doxycycline 100 mg PO bid x 7 days
Disseminated N. gonorrhaeae	Ceftriaxone 1 g q12 hrs for 4 doses then switch to Ofloxacin 400 mg PO qday for 7 days
Pelvic Inflammatory Disease (PID) Gonococcus;  Chlamydia;  Bacteroides;  Enteric G-negatives	Outpatient - Ceftriaxone 250 mg IM + doxycycline PO bid for 14 days Inpatient - Cefotetan 2 g q 12 IV + doxycycline bid for 14 days	Candidates for outpatient: temp <38 °C, WBC <11,000, no indication of peritonitis
Genital lesions
Herpes Simplex / HSV	Acyclovir
Chancroid Hemophilus ducreyi	Ceftriaxone 250 mg IM single dose or Azithromycin 1 g PO single dose
Lymphogranuloma venereum Chlamydia	Doxycycline 100 mg PO bid x 21 days	This disease is rare in the USA
Syphillis Primary / Secondary / Latent < 1 yr Treponema pallidum	Benzathine PCN 2.4 million units IM single dose	HIV patients and pregnant patients with syphilis should have infectious disease consults Benzathine PCN 2.4 million units dose should be divided in two injection sites
Syphillis Latent > 1 yr or unknown duration Treponema pallidum	Benzathine PCN 2.4 million units IM once a week x 3 doses
Neurosyphilis Treponema pallidum	Penicillin G 2 - 4 million units q 4 hrs x 14 days (2-4 mu q 4 hr)

Related Links
NFID Factsheets	ISDA practice guidelines

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