Valaciclovir


Concise Prescribing Info
Indications/Uses
Listed in Dosage.
Dosage/Direction for Use
Adult : PO Herpes zoster (shingles); Herpes zoster ophthalmicus Immunocompetent patients: 1,000 mg tid for 7 days. Immunocompromised patients: 1,000 mg tid for at least 7 days and for 2 days after crusting of lesions.  Herpes simplex infections of skin and mucous membranes; Genital herpes Immunocompetent patients: 500 mg bid for 3-5 days for recurrent episodes or for up to 10 days for initial episodes. Immunocompromised patients: 1,000 mg bid for at least 5 days for recurrent episodes or for up to 10 days for initial episodes. Treatment duration is based on severity of clinical condition and patient’s immunological status. Herpes labialis 2,000 mg 12 hourly for 1 day. Suppression of recurrent herpes simplex Immunocompetent patients: 500 mg once daily. Patient with ≥10 relapses a year: 250 mg bid. Immunocompromised patients: 500 mg bid. Re-evaluate treatment after 6-12 months of therapy. Prophylaxis of cytomegaloviral infections in immunocompromised patients Patient following solid organ transplantation: 2,000 mg 4 times daily, usually for 90 days according to patient response.
Dosage Details
Oral
Genital herpes, Herpes simplex infections of skin and mucous membranes
Adult: Immunocompetent patients: 500 mg bid for 3-5 days for recurrent episodes or for up to 10 days for initial episodes. Immunocompromised patients: 1,000 mg bid for at least 5 days for recurrent episodes or for up to 10 days for initial episodes. Treatment duration is based on severity of clinical condition and immunological status.
Child: ≥12 years Same as adult dose.

Oral
Herpes zoster (shingles), Herpes zoster ophthalmicus
Adult: Immunocompetent patients: 1,000 mg tid for 7 days. Immunocompromised patients: 1,000 mg tid for at least 7 days and for 2 days after crusting of lesions.

Oral
Herpes labialis
Adult: 2,000 mg 12 hourly for 1 day.
Child: ≥12 years Same as adult dose.

Oral
Prophylaxis of cytomegaloviral infections in immunocompromised patients
Adult: Patient following solid organ transplantation: 2,000 mg 4 times daily, usually for 90 days according to patient response.
Child: ≥12 years Same as adult dose.

Oral
Suppression of recurrent herpes simplex
Adult: Immunocompetent patients: 500 mg once daily. Patient with ≥10 relapses a year: 250 mg bid. Immunocompromised patients: 500 mg bid. Re-evaluate treatment after 6-12 months of therapy.
Child: ≥12 years Same as adult dose.
Renal Impairment
Herpes zoster (shingles); Herpes zoster ophthalmicus
Patient on haemodialysis: Lowest recommended dose after the dialysis session.
CrCl (mL/min) Dosage
30-49 Immunocompetent and immunocompromised patients: 1,000 mg bid.
10-29 Immunocompetent and immunocompromised patients: 1,000 mg once daily.
<10 Immunocompetent and immunocompromised patients: 500 mg once daily.
               
Herpes simplex infections of skin and mucous membranes; Genital herpes
Patient on haemodialysis: Lowest recommended dose after the dialysis session.
CrCl (mL/min) Dosage
≥30 Immunocompetent patients: 500 mg bid. Immunocompromised patients: 1,000 mg bid.
<30 Immunocompetent patients: 500 mg once daily. Immunocompromised patients: 1,000 mg once daily.
               
Herpes labialis:
Patient on haemodialysis: Lowest recommended dose after the dialysis session.
CrCl (mL/min) Dosage
30-49 1,000 mg 12 hourly for 1 day.
10-29 500 mg 12 hourly for 1 day.
<10 500 mg as a single dose. 

Suppression of recurrent herpes simplex:
CrCl (mL/min) Dosage
≥30
Immunocompetent patients: 500 mg once daily; Patient with ≥10 relapses a year: 250 mg bid; Immunocompromised patients: 500 mg bid.
<30
Immunocompetent patients: 250 mg once daily. Immunocompromised patients: 500 mg once daily.

Prophylaxis of cytomegaloviral infections in immunocompromised patients:
Patient on haemodialysis: 1,500 mg once daily.
CrCl (mL/min)
Dosage
50-74
1,500 mg 4 times daily.
25-49
1,500 mg tid.
10-24
1,500 mg bid.
<10
1,500 mg once daily.
               
Administration
May be taken with or without food. May be taken w/ meals to reduce GI discomfort.
Contraindications
Hypersensitivity.
Special Precautions
Patients inadequately hydrated or at risk of dehydration; immunocompromised patients. Concomitant use with nephrotoxic agents. Renal and hepatic impairment. Elderly. Pregnancy and lactation.
Adverse Reactions
Significant: Acute renal failure, CNS effects (e.g. agitation, hallucination, confusion, delirium, seizures, encephalopathy).
Blood and lymphatic system disorders: Thrombocytopenia, leucopenia.
Gastrointestinal disorders: Nausea, abdominal pain, vomiting, diarrhoea.
General disorders and admin site conditions: Fatigue, ataxia, fever.
Immune system disorders: Urticaria. Rarely, anaphylaxis, angioedema.
Investigations: Elevated liver enzymes.
Metabolism and nutrition disorders: Dehydration.
Musculoskeletal and connective tissue disorders: Arthralgia.
Nervous system disorders: Headache, dizziness, decreased consciousness, tremor.
Psychiatric disorders: Dysarthria.
Renal and urinary disorders: Renal pain, haematuria.
Reproductive system and breast disorders: Dysmenorrhoea.
Respiratory, thoracic and mediastinal disorders: Nasopharyngitis, dyspnoea.
Skin and subcutaneous tissue disorders: Rashes, pruritus, photosensitivity.
Potentially Fatal: In patients with advanced HIV infection receiving high doses (8,000 mg daily) for prolonged period: Thrombotic thrombocytopenic purpura, haemolytic uremic syndrome.
Patient Counseling Information
This drug does not reduce your risk of passing genital herpes through sexual contact, if symptoms are present, avoid sexual intercourse or use safer sex practices.
MonitoringParameters
Monitor LFTs, CBC, BUN, serum creatinine and urinalysis regularly during treatment. Assess for signs of CNS changes.
Overdosage
Symptoms: Acute renal failure, nausea, vomiting, confusion, agitation, hallucinations, decreased consciousness, and coma. Management: May consider haemodialysis to enhance removal of aciclovir from the blood.
Drug Interactions
Increased risk of renal impairment with nephrotoxic drugs (e.g. aminoglycosides, organoplatinum compounds, iodinated contrast media, methotrexate, pentamidine, foscarnet, ciclosporin, tacrolimus). Probenecid and cimetidine may reduce renal clearance of aciclovir.
Action
Description: Valaciclovir is rapidly and almost completely converted via hepatic and intestinal metabolism to aciclovir, then converted to aciclovir monophosphate by virus-specific thymidine kinase, then further converted to aciclovir triphosphate by other cellular enzymes. Aciclovir triphosphate inhibits DNA synthesis and viral replication by competing with deoxyguanosine triphosphate for viral DNA polymerase and being incorporated into viral DNA.
Pharmacokinetics:
Absorption: Rapidly absorbed from the gastrointestinal tract. Bioavailability: Approx 54% (aciclovir). Time to peak plasma concentration: Approx 1-2 hours.
Distribution: Widely distributed into body organs, muscle, uterus, vagina and CSF. Enters breast milk (aciclovir). Plasma protein binding: Approx 14-18%.
Metabolism: Converted to aciclovir and L-valine via first-pass intestinal and/or hepatic metabolism. Aciclovir is converted to a small extent by aldehyde oxidase and by alcohol and aldehyde dehydroxegenase to its inactive metabolites.
Excretion: Mainly via urine (89% as aciclovir; <1% as unchanged drug); faeces (46% as non-absorbed drug). Elimination half-life: Approx 30 minutes (valaciclovir); 2.5-3.3 hours (aciclovir). End-stage renal disease: 14-20 hours (aciclovir); During hemodialysis: 4 hours.
Chemical Structure

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Storage
Store between 15-25°C.
MIMS Class
ATC Classification
J05AB11 - valaciclovir ; Belongs to the class of nucleosides and nucleotides excluding reverse transcriptase inhibitors. Used in the systemic treatment of viral infections.
Disclaimer: This information is independently developed by MIMS based on Valaciclovir from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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