RISK FACTORS: Immune compromise (brief as with occurrence of other illness or more chronic as with chemotherapy), Newborns - if exposed to actively infected mother birth canal or risk greatest for neonate of mother with active primary infection
* - Thirty to 60% of women receiving obstetric care have serologic evidence of past HSV infection. Although both HSV-1 and HSV-2 may cause neonatal herpes, HSV-2 is responsible for 70% of cases. Ninety percent of infections are perinatally transmitted as a result of acquisition of the virus in the birth canal. HSV acquired in this manner has a 70% risk of dissemination and is associated with skin lesions, encephalitis, and neurological disability. Approximately 10% of infections are congenital, usually a consequence of the mother acquiring HSV during pregnancy and the fetus acquiring the infection transplacentally or via an ascending infection from the cervix. This route of infection is associated with intrauterine growth restriction, preterm labor, and miscarriage (Brown, 1997; Covey, 2000). The risk of neonatal herpes and death is highest in infants born to mothers who have not seroconverted at the time of birth.
DRUG(S) OF CHOICE
o Acyclovir
? Primary herpes labialis: 15 mg/kg (up to 200 mg) po x 5 doses daily for 5 days
? Primary genital herpes: 400 mg po tid or 200 mg po x 5 doses daily for 7-10 days
? Recurrent genital herpes: 800 mg bid or 200 mg po x 5 doses daily for 5 days; for chronic suppression in
persons with frequent recurrences - 400 mg bid
? Neonatal herpes simplex or encephalitis: 20 mg/kg IV over 1 hour q8h x 14-21 days
? Primary herpes gingivostomatitis, recurrent herpes labialis and other HSV skin infections: 200 mg po q4h
x 5 doses daily for 10 days
o Penciclovir (Denavir)
? Oroherpes recurrence: 1% cream q2h while awake for 4 days
o Valacyclovir (Valtrex): better bioavailability orally than acyclovir, is converted to acyclovir
? Primary genital herpes: 1 gm po bid for 10 days
? Recurrent genital herpes: 500 mg po bid for 3 days; chronic suppression 1 g po q/day (10 or more
recurrences per year) or 500 mg po q/day (9 or less recurrences per year)
o Famciclovir (Famvir): is converted to penciclovir, with longer intracellular half-life and higher levels than
acyclovir
? Primary genital herpes: 250 mg po tid for 7-10 days
? Recurrent genital herpes: 125 mg po bid for 5 days; chronic suppression 250 mg po bid
Contraindications: Acyclovir, valacyclovir, or famciclovir: Hypersensitivity or intolerance
Precautions:
o Reduce dosage in renal insuffi ciency for acyclovir, valacyclovir and famciclovir
o Acyclovir may produce encephalopathic reactions, particularly in the elderly
o Valacyclovir: Thrombotic thrombocytopenia purpura/hemolytic uremic syndrome (TTP/HUS) reported in some immunocompromised persons in trials on high doses (8 grams daily) for CMV suppression
o Pregnancy - see Miscellaneous section Significant possible interactions: Probenecid with IV acyclovir, possibly probenecid with valacyclovir can reduce renal clearance and elevate antiviral drug levels
ALTERNATIVE DRUGS
o Foscarnet: Drug of choice for acyclovir-resistance in immunocompromised persons with systemic HSV; 40
mg/kg IV q8h (assume valacyclovir and famciclovir resistance also if acyclovir resistance occurs)
o Other topicals:
? Ophthalmic preparations for herpes keratoconjunctivitis: Acyclovir, vidarabine (Vira-A), idoxuridine and
trifl uorothymidine; refer to ophthalmologist
PATIENT MONITORING Observe for disappearance of lesions and resolution of systemic
manifestations
POSSIBLE COMPLICATIONS Herpes encephalitis - brain biopsy may be needed for diagnosis;
herpes pneumonia; aseptic meningitis; herpes viremia
EXPECTED COURSE/PROGNOSIS
Good for treatment of recurrent episodes. Expect frequent recurrences.
PREGNANCY
. May give acyclovir orally for fi rst episode genital herpes or severe recurrent herpes. Give IV for severe or
complicated disease.
. Risk of viral shedding at delivery from asymptomatic recurrent genital HSV low (.1.6%); not predicted by
monitoring cultures
. Attack rate for neonatal HSV is 30-50% if primary maternal genital HSV present at time of delivery and <1% for recurrent genital HSV at time of delivery. Avoid fetal scalp electrodes if maternal history of genital HSV.
. C-section and/or acyclovir indicated if any active genital lesions (or prodrome) present at time of delivery;
consider if primary genital herpes occurred within 4 wks of expected delivery
. Obtain HSV cultures (urine, stool, CSF, eyes, throat) of neonates exposed to primary maternal genital HSV
at delivery; treat with acyclovir if clinically ill, cultures positive, CSF abnormal
. Neonates with possible exposure to HSV with signs of infection: lethargy, poor feeding, fever, or lesions;
admit, culture; treat immediately with IV acyclovir if HSV illness suspected