Encephalitis Treatment Guidelines

Initial Management

The Infectious Diseases Society of America recommends starting acyclovir within 6 hours of admission if encephalitis is suspected, even while awaiting diagnostic test results, as early treatment significantly reduces mortality from 70% to 8-30% 1, 4, 5
For adults and children with normal renal function, the American Academy of Neurology suggests administering acyclovir 10 mg/kg intravenously every 8 hours 1, 2
For neonates, the American Academy of Pediatrics recommends using higher-dose acyclovir at 20 mg/kg intravenously every 8 hours, which has reduced mortality to 5% 6
The Centers for Disease Control and Prevention advises reducing acyclovir dose in patients with pre-existing renal impairment to prevent crystalluria and obstructive nephropathy 4, 5

The Infectious Diseases Society of America recommends continuing intravenous acyclovir for 14-21 days in confirmed HSV encephalitis 5
The American Academy of Neurology suggests considering repeating lumbar puncture at the end of treatment to confirm CSF is negative for HSV by PCR 5
The Centers for Disease Control and Prevention advises monitoring renal function throughout treatment, as acyclovir-induced nephropathy can affect up to 20% of patients, typically after 4 days of IV therapy 4, 5

The American Academy of Neurology recommends acyclovir as the treatment of choice for HSV encephalitis 1
Predictors of poor outcome include age >30 years, Glasgow coma score <6, and treatment delay >4 days after symptom onset 6

The Infectious Diseases Society of America recommends using combination therapy with ganciclovir (5 mg/kg IV every 12h) and foscarnet (60 mg/kg IV every 8h or 90 mg/kg IV every 12h) for 3 weeks for CMV encephalitis 6
This combination has shown improvement or stabilization in 74% of patients with CMV encephalitis 6

The American Academy of Neurology advises that acyclovir has limited benefit for EBV encephalitis and is not recommended 6
The Infectious Diseases Society of America suggests that corticosteroids may be beneficial in selected patients with EBV-associated neurologic complications 7

The Infectious Diseases Society of America recommends that immunocompromised patients may require longer courses of therapy and closer monitoring 3

The American Academy of Neurology advises that delaying acyclovir treatment beyond 48 hours after hospital admission significantly worsens outcomes 1, 3
The Centers for Disease Control and Prevention recommends avoiding empirical use of antimicrobials without thorough diagnostic workup, as it can lead to missed alternative diagnoses 5
The Infectious Diseases Society of America suggests that inadequate hydration during acyclovir treatment increases risk of nephropathy 4, 5