Zovirax

Tab: HSV infections of the skin & mucous membranes including initial & recurrent genital herpes. Suppression/prevention of recurrent herpes simplex infections in immune-competent patients. Prophylaxis of herpes simplex infections in immune-compromised patients. Varicella infections (chickenpox) & herpes zoster (shingles). Management of certain severely immunocompromised patients, w/ advanced HIV disease (CD4+ counts <200/mm³, including patients w/ AIDS or severe AIDS-related complex) or following bone marrow transplantation. Prophylaxis for herpes virus disease. Powd for IV infusion: Herpes simplex infections. Prophylaxis of herpes simplex infections in immune-compromised patients. Varicella zoster infections; herpes simplex infections in the neonate.

Tab Treatment of herpes simplex Adult 200 mg 5 times daily at approx every 4 hr intervals (omitting the nighttime dose) for 5 days. Severely immune-compromised adult (eg, after marrow transplant) or adult w/ impaired gut absorption Dose can be doubled to 400 mg or alternatively, IV dosing could be considered. Suppression of herpes simplex infection Immune-competent adult 200 mg qid at approx every 6-hr intervals or 400 mg bid at approx every 12-hr intervals. May titrate dose to 200 mg tid at approx every 8-hr intervals or 200 mg bid at approx every 12-hr intervals. Periodically interrupt therapy at 6-12 mth intervals. Prophylaxis of herpes simplex Immune-compromised adult 200 mg qid at approx every 6-hr intervals. Severely immune-compromised adult (eg, after marrow transplant) or adult w/ impaired gut absorption Dose can be doubled to 400 mg or alternatively, IV dosing could be considered. Treatment of varicella & herpes zoster Adult 800 mg 5 times daily at approx every 4-hr intervals (omitting the nighttime dose) for 7 days. Severely immune-compromised adult or adult w/ impaired gut absorption Consider IV dosing. Patient w/ moderate renal impairment (CrCl 10-25 mL/min) 800 mg tid at approx 8-hr intervals, severe renal impairment (CrCl <10 mL/min) 800 mg bid at approx 12-hr intervals. Management of severely immunocompromised patient Adult 800 mg qid at approx every 6-hr intervals. Patient w/ moderate renal impairment (CrCl 10-25 mL/min) 800 mg tid at approx 8-hr intervals, severe renal impairment (CrCl <10 mL/min) 800 mg bid at approx 12-hr intervals. Treatment & prophylaxis of herpes simplex Immune-compromised patient ≥2 yr Adult dose, <2 yr ½ the adult dose. Patient w/ severe renal impairment (CrCl <10 mL/min) 200 mg bid at approx every 12-hr intervals. Treatment of varicella infection Childn ≥6 yr 800 mg qid for 5 days, 2-<6 yr 400 mg qid for 5 days, <2 yr 200 mg qid or 20 mg/kg for 5 days. Max: 800 mg qid. Powd for IV infusion Herpes simplex Adult 5 mg/kg every 8 hr (except for herpes encephalitis). Infant & childn ≥3 mth 20 mg/kg every 8 hr for 21 days for herpes encephalitis, or for 14 days for disease limited to skin & mucous membrane. Herpes encephalitis Adult 10 mg/kg every 8 hr. Prophylaxis of herpes simplex Immune-compromised adult 5 mg/kg every 8 hr. Immune-compromised infant & childn 20 mg/kg every 8 hr for 21 days for herpes encephalitis, or for 14 days for disease limited to skin & mucous membrane. Varicella & herpes zoster Adult 5 mg/kg every 8 hr. Immune-compromised adult w/ varicella zoster 10 mg/kg every 8 hr. Infant & childn 20 mg/kg every 8 hr. Known or suspected neonatal herpes 20 mg/kg every 8 hr for 21 days for disseminated & CNS disease, or 14 days for disease limited to the skin & mucous membranes. HSV infection Adult & adolescent w/ renal impairment CrCl 25-50 mL/min 5 or 10 mg/kg every 12 hr, CrCl 10-25 mL/min 5 or 10 mg/kg every 24 hr, CrCl 0 (anuric)-10 mL/min 5 or 10 mg/kg halved & administered every 24 hr, on haemodialysis 5 or 10 mg/kg halved & administered every 24 hr & after dialysis. Neonate, infant & childn w/ renal impairment CrCl 25-50 mL/min 20 mg/kg bid, CrCl 10-25 mL/min 10 mg/kg bid, CrCl 0 (anuric)-10 mL/min 5 mg/kg bid, on haemodialysis 5 mg/kg bid after dialysis.

Tab: May be taken with or without food: May be taken w/ meals to reduce GI discomfort.

Hypersensitivity to acyclovir or valacyclovir.

Maintain adequate hydration in high dose therapy. Patients w/ renal impairment. Pregnancy & lactation. Elderly.

Nausea, vomiting; pruritus, rashes (including photosensitivity). Tab: Headache, dizziness; diarrhoea, abdominal pain; fatigue, fever. Powd for IV infusion: Phlebitis; reversible increases in liver-related enzymes; urticaria; increased blood urea & creatinine.

Increased plasma conc w/ any drugs competing w/ acyclovir elimination via active renal tubular secretion. Increased AUC & reduced renal clearance w/ probenecid & cimetidine. Increased plasma AUCs of acyclovir & inactive metabolite of mycophenolate mofetil when co-administered. Powd for IV infusion: Monitor for changes in renal function if co-administering w/ drugs which affect other aspects of renal physiology eg, cyclosporin & tacrolimus.

Antivirals

J05AB01 - aciclovir ; Belongs to the class of nucleosides and nucleotides excluding reverse transcriptase inhibitors. Used in the systemic treatment of viral infections.

Rx