Viral Meningitis / Encephalitis

First Line

Aciclovir 10mg/kg IV every 8 hours - Use ideal body weight if obese

IV route necessary to ensure adequate tissue levels

Adjust dose in renal impairment


If intravenous aciclovir is not available – alternative options are:

PO valaciclovir 1g  8 hourly

(n.b Not available as suspension. Tablets are hard, do not disperse easily, are difficult to crush and the powder does not suspend well. Rinse crushing device and plastic container to ensure full dose given)


IV foscarnet 60mg/kg  8 hourly (ensure adequate patient hydration and monitor renal function)


IV ganciclovir 5mg/kg  12 hourly  (associated with bone marrow suppression – avoid if low Hb, WCC, platelets)


Viral meningitis (including HSV and VZV) is commonly a self-limiting illness. Antiviral treatment should be used where there are clinical features of encephalitis or in systemically unwell immunocomprimised patient (i.e. possible viraemia)