Bacterial infections

Use at a glance

• Treat only when bacterial infection is likely/confirmed

Safety / pitfalls

• Obtain cultures before antibiotics when this will not delay care

Practical pearls

• Site + severity determine empiric spectrum
• Source control is essential for abscess/obstruction/device disease

Choosing treatment

• Narrow therapy when microbiology permits

Other practical pearls

• Shortest effective duration reduces toxicity/resistance

Key points

• Treat empirically; culture/sensitivity → narrower agent; shorter courses favored (↓ resistance, AEs)
• Most pharyngitis/sinusitis/bronchitis viral → no antibiotics; GAS pharyngitis: penicillin ×10 d
• Bacterial sinusitis, AECB: amoxicillin/clavulanate; FQs last resort for uncomplicated sinusitis/bronchitis/cystitis (FDA: serious AEs)
• CAP: no macrolide monotherapy (>40% pneumococcal resistance); doxycycline, β-lactam + macrolide, or respiratory FQ
• Purulent SSTI/MRSA: TMP-SMX, doxycycline, clindamycin; IV vancomycin if hospitalized. Nonpurulent cellulitis: penicillin/1st-gen cephalosporin
• Uncomplicated cystitis: TMP-SMX, nitrofurantoin, single-dose fosfomycin; outpatient pyelonephritis: cipro/levo if FQ resistance <10%
• Avoid FQs for cystitis, nitrofurantoin/fosfomycin for pyelonephritis; clarithromycin ↑ cardiac events/death in CAD

Nonpharmacologic therapies

• Abscess incision and drainage
• Surgical debridement
• Nasal saline irrigation

Pearls

• Don't treat asymptomatic bacteriuria in nonpregnant women
• Negative rapid strep with high suspicion → culture
• One IV aminoglycoside dose can bridge pyelonephritis pending cultures
• Most skin infections: 5 days is enough
• Cystitis: 3 days TMP-SMX or 5 days nitrofurantoin

Self-check

• In which infections is source control essential?
  Abscess, obstruction or device disease.
• When should cultures precede antibiotics?
  When this will not delay care.

Drugs used for this (42)

All clinical uses · Open Bacterial infections in the interactive console ↗