200-400 mg PO 5 times per day x 5 days
Genital (primary or nonprimary episode):
200 mg PO 5 times per day x 5-10 days
Recurrent Genital Lesions:
200 mg PO 5 times per day x 5 days
800 mg PO TID x 2 days
Initiate at onset of symptoms
Unable to take oral or severe mucocutaneous infection: 5 mg/kg IV Q8H
(Switch to oral once improved).
(e.g. CNS and Disseminated): 10mg/kg IV q8h
Chicken Pox in Adulthood:
800mg PO QID x 5 days
800 mg 5 times per day x 7-10 days
(e.g. CNS and Disseminated)
10-15 mg/kg IV q8h (higher doses typically reserved in HIV/immune compromise - see full guidelines or consult ID for details)
Prophylaxis dosing varies by indication refer to specific treatment guidelines.
See Canadian Guidelines on Sexually Transmitted Infections for full management recommendations for HSV.
Manufacturer recommends dosing using IBW (ideal body weight) but can consider adjusted body weight (IBW + 0.4x[TBW-IBW]) for severe (CNS or other) infections.
CrCl Greater Than 50 mL/minCrCl 25-49 mL/minCrCl 10-24 mL/minCrCl Less Than 10 mL/minUsual dosingReduce dosing to q12hReduce doing to q24h50% dose q24h
|CrCl Greater Than 50 mL/minCrCl 25-49 mL/minCrCl 10-24 mL/minCrCl Less Than 10 mL/minNo dose adjustment requiredNo dose adjustment requiredIf dose was||Reduce to|
|800 mg 5x/day||800 mg TID|
|800 mg QID||800 mg TID|
|800 mg TID||800 mg TID|
|400 mg 5x/day||400 mg TID|
|200 mg 5x/day||No adjustment|
|800 mg 5x/day||800 mg BID|
|800 mg QID||800 mg BID|
|800 mg TID||800 mg BID|
|400 mg 5x/day||400 mg BID|
|200 mg 5x/day||200 mg BID|
Follow SCr as appropriate.
Check urine for crystals if AKI suspected.
AKI from crystal nephropathy
Mycophenolate can increase the acyclovir concentration.
May diminish efficacy of zoster or varicella vaccine.
For oral indications, valacyclovir is the pro-drug, which is more bioavailable with more convenient dosing.
Antimicrobial class: Antiviral. Nucleoside analogue.
Pregnancy category: B
Average serum half life: 3 hours, longer if renal dysfunction
CSF penetration: Therapeutic
Urine penetration: Therapeutic
Therapy for herpesviral infections (HSV and VZV) including encephalitis.
Prophylaxis of herpesviral infections if recurrent disease or immunocompromised.