ACYCLOVIR
(Zovirax)Standard Prescription
acyclovir __mg PO {IV} Q__H (__mg/kg/24 hr)
Dosages
Neonatal HSV (birth to 3 mo):
HSV Suppressive Therapy following Neonatal HSV infection:
HSV Encephalitis:
Children <= 3 mos: 20 mg/kg/dose IV Q8H x 21 days*
HSV (Mucocutaneous) Infection in Immunocompetent (>= 2 yo):
PO: 15-25 mg/kg/dose PO TID or 10-20 mg/kg/dose PO QID (40-80
mg/kg/24 hr PO div. TID to QID) x 5-7 days. Maximum 800 mg/dose PO TID.
Genital HSV Infection Treatment in Immunocompetent (Adolescents and Adults)
PO: 400 mg PO TID x 7-10 days or 200 mg 5 times a day x 7-10 days
IV: 5 mg/kg/dose IV Q8H x 5 days
Suppressive therapy: 400-800 mg PO BID
Chronic Suppressive Therapy for Recurrent Genital and Cutaneous HSV
Episodes.
HSV Infection in Immunocompromised (>= 2 yo):
PO: 200 mg PO five times daily or 1000 mg/24 hr in 3 to 5 divided doses x
7-14 days
IV: 10 mg/kg/dose IV Q8H x 7-14 day or 250 mg/ m2/dose IV Q8H x 7-14
HSV Prophylaxis in Transplant Patients:
HSV Prophylaxis in Immunocompromised Patients Who Are HSV Seropositive:
Varicella (chickenpox) Treatment in Immunocompetent:
PO: 20 mg/kg/dose PO QID x 5 days. Maximum: 800 mg/dose***.
Varicella (chickenpox) Treatment in Immunocompromised:
Zoster (shingles) Treatment in Immunocompetent:
> 12 yrs and adults: PO: 800 mg PO 5 times a day x 5-7 days
Zoster (shingles) Treatment in Immunocompromised:
20 mg/kg/dose IV Q8H x 14- 21 days*
300 mg/m2/dose PO TID x 6 months
Children <= 3 mos: 20 mg/kg/dose IV Q8H x 21 days*
Children > 3 mos: 10 mg/kg/dose IV Q8H x 21 days**
PO: 15-25 mg/kg/dose PO TID or 10-20 mg/kg/dose PO QID (40-80
mg/kg/24 hr PO div. TID to QID) x 5-7 days. Maximum 800 mg/dose PO TID.
IV: 5 mg/kg/dose IV Q8H x 5-7days
PO: 400 mg PO TID x 7-10 days or 200 mg 5 times a day x 7-10 days
IV: 5 mg/kg/dose IV Q8H x 5 days
Suppressive therapy: 400-800 mg PO BID
Episodic therapy: 400 mg PO TID x 5 days
Episodes.
15-25 mg/kg/dose PO TID. Maximum 400 mg/dose po TID.
PO: 200 mg PO five times daily or 1000 mg/24 hr in 3 to 5 divided doses x
7-14 days
IV: 10 mg/kg/dose IV Q8H x 7-14 day or 250 mg/ m2/dose IV Q8H x 7-14
days
IV: 250 mg/m2/dose IV Q12H in HSV sero-positive patients to day + 30
PO: 600-1000 mg/24hr in 3-5 div doses during risk period
PO: 20 mg/kg/dose PO QID x 5 days. Maximum: 800 mg/dose***.
IV: >= 2 yr: 10 mg/kg/dose IV Q8H x 7-10 days.
IV: 10 mg/kg/dose IV Q8H x 7-14 days.****
> 12 yrs and adults: PO: 800 mg PO 5 times a day x 5-7 days
IV: 10 mg/kg/dose IV div. Q8H x 7-10 days
IV: 10 mg/kg/dose IV Q8H x 7-10 days
VZV Prophylaxis in Transplant Patients with Previous Varicella Infection
PO: 30-45 mg/kg/dose PO BID or 20-30 mg/kg/dose PO TID. Maximum 800mg PO BID.
Mechanism of Action
Antiviral.
Forms Supplied
Tablet: 200 mg
Suspension: 40 mg/1 mL
Injection: 500 mg/vial
Suspension: 40 mg/1 mL
Injection: 500 mg/vial
Comments
Oral absorption is unpredictable (15 to 30%). Valacyclovir is an oral prodrug of acyclovir and offers improved bioavailability.
Keep well hydrated to prevent nephrotoxicity due to crystallization in renal tubules.
Minimum dilution for IV use is 10 mg/mL.
Dosage adjustment required in renal impairment.
In obese patients, calculate dosage using ideal body weight.
May cause nausea, vomiting, diarrhea, headache, dizziness, neurotoxicity, arthralgia, fatigue, rash, insomnia, fever.
May decrease clearance of methotrexate.
* If limited to skin, eye and mucous membrane HSV infection, treat for minimum 14 days. If disseminated or CNS disease, treat for minimum duration of 21 days.
** Doses up to 20 mg/kg/day are approved for children <12 yo. However, there is no evidence for increased efficacy, and higher doses may increase risk of nephrotoxicity.
*** Must be started within 24 hr of rash for clinical benefit.
**** Therapy should continue until no new lesions have appeared for 48 hours, which may be less than 7-10 days.
Keep well hydrated to prevent nephrotoxicity due to crystallization in renal tubules.
Minimum dilution for IV use is 10 mg/mL.
Dosage adjustment required in renal impairment.
In obese patients, calculate dosage using ideal body weight.
May cause nausea, vomiting, diarrhea, headache, dizziness, neurotoxicity, arthralgia, fatigue, rash, insomnia, fever.
May decrease clearance of methotrexate.
* If limited to skin, eye and mucous membrane HSV infection, treat for minimum 14 days. If disseminated or CNS disease, treat for minimum duration of 21 days.
** Doses up to 20 mg/kg/day are approved for children <12 yo. However, there is no evidence for increased efficacy, and higher doses may increase risk of nephrotoxicity.
*** Must be started within 24 hr of rash for clinical benefit.
**** Therapy should continue until no new lesions have appeared for 48 hours, which may be less than 7-10 days.
References
6, 44, 355, 356, 357, 358
Last Edited
2022-06-09 04:28:04