What it's for (Indications)
- Valacyclovir is used for the treatment of Herpes Zoster (shingles), Herpes Simplex infections of the skin and mucous membranes (e.
- g.
- , cold sores, ocular infections), and initial and recurrent genital herpes.
- It is also indicated for the suppression of recurrent genital herpes infections, reduction of transmission of genital herpes, and treatment of chickenpox in pediatric patients.
Dosage Information
| Type | Guideline |
|---|---|
| Standard | Valacyclovir tablets may be administered without regard to meals. An oral suspension (25 mg/mL or 50 mg/mL) can be extemporaneously prepared from 500-mg tablets for pediatric patients unable to take a solid dosage form. Adult Dosage: - Cold Sores: 2 grams every 12 hours for 1 day. - Genital Herpes (Initial Episode): 1 gram twice daily for 10 days. - Genital Herpes (Recurrent Episodes): 500 mg twice daily for 3 days. - Genital Herpes (Suppressive Therapy, Immunocompetent Patients): 1 gram once daily, or an alternate dose of 500 mg once daily for patients with ≤ 9 recurrences/year. - Genital Herpes (Suppressive Therapy, HIV-1–infected Patients): 500 mg twice daily. - Reduction of Transmission of Genital Herpes: 500 mg once daily. - Herpes Zoster: 1 gram 3 times daily for 7 days. Pediatric Dosage: - Cold Sores (aged ≥ 12 years): 2 grams every 12 hours for 1 day. - Chickenpox (aged 2 to < 18 years): 20 mg/kg 3 times daily for 5 days, not to exceed 1 gram 3 times daily. |
Safety & Warnings
Common Side Effects
- Common adverse reactions include headache, nausea, gastrointestinal disturbances (such as abdominal pain), and skin reactions.
- More serious adverse reactions that have been reported include Thrombotic Thrombocytopenic Purpura/Hemolytic Uremic Syndrome, Acute Renal Failure, Central Nervous System Effects, and Severe Cutaneous Adverse Reactions.
Serious Warnings
- Black Box Warning: None
- Caution is advised in patients with renal (kidney) and hepatic (liver) impairment, those undergoing hemodialysis, and the elderly.
- The effects of valacyclovir during pregnancy and lactation are undetermined; therefore, consultation with a healthcare professional is advised before use in these populations.
- Patients should be monitored for serious adverse effects such as Thrombotic Thrombocytopenic Purpura/Hemolytic Uremic Syndrome, Acute Renal Failure, Central Nervous System Effects, and Severe Cutaneous Adverse Reactions.
How it Works (Mechanism of Action)
Valacyclovir is an antiviral drug active against α-herpes viruses. It is a deoxynucleoside analogue DNA polymerase inhibitor that is rapidly converted to acyclovir. Acyclovir, a synthetic purine deoxynucleoside, is phosphorylated intracellularly by viral thymidine kinase (TK) into acyclovir monophosphate, which is then further converted to diphosphate and triphosphate by cellular enzymes. Acyclovir triphosphate inhibits replication of α-herpes viral DNA by three primary mechanisms: competitive inhibition of viral DNA polymerase, incorporation into and termination of the growing viral DNA chain, and inactivation of the viral DNA polymerase.
Commercial Brands (Alternatives)
No other brands found for this formula.