DRUG | SUPPLIED | DOSE | COMMENTS |
---|---|---|---|
ACYCLOVIR (Paeds) (Zovirax) Mechanism of action: Antiviral. Ref: 6, 44, 355, 356, 357, 358 Last update: 2022-06-09 |
Tablet: 200 mg Suspension: 40 mg/1 mL Injection: 500 mg/vial |
Neonatal HSV (birth to 3 mo): 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. |
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. Standard Prescription: acyclovir __mg PO {IV} Q__H (__mg/kg/24 hr) |