From the FDA Drug Label
The recommended dosage of VALTREX for treatment of herpes zoster is 1 gram 3 times daily for 7 days Therapy should be initiated at the earliest sign or symptom of herpes zoster and is most effective when started within 48 hours of the onset of rash.
The recommended dosing of Valtrex (valacyclovir) for the treatment of shingles rash is 1 gram 3 times daily for 7 days. Therapy should be initiated at the earliest sign or symptom of herpes zoster and is most effective when started within 48 hours of the onset of rash 1.
- Key points:
- Dosage: 1 gram 3 times daily
- Duration: 7 days
- Initiation: at the earliest sign or symptom of herpes zoster
- Timing: most effective when started within 48 hours of the onset of rash
From the Research
For the treatment of shingles rash, the recommended dosage of Valtrex (valacyclovir) is 1.5 g taken orally twice daily for 7 days, as this dosing schedule has been shown to be safe and effective in immunocompetent patients over 18 years of age 2.
Key Considerations
- Treatment should be started as soon as possible after diagnosis, ideally within 72 hours of rash onset, to achieve the best outcomes.
- The medication should be taken with or without food, and patients should complete the full course even if symptoms improve before the 7 days are finished.
- Adequate hydration should be maintained while taking Valtrex.
- For patients with kidney impairment, dose adjustment may be necessary, but the provided evidence does not specify the exact adjustments for valacyclovir 1.5 g twice daily.
Mechanism and Side Effects
- Valtrex works by converting to acyclovir in the body, which inhibits viral DNA synthesis and replication of the varicella-zoster virus that causes shingles.
- Common side effects may include headache, nausea, and dizziness, but these are generally mild and transient.
Comparison with Other Studies
- Other studies have compared valacyclovir with acyclovir and famciclovir, showing that valacyclovir is at least as effective and has a simpler dosing regimen 3, 4, 5.
- However, the study with the most recent and highest quality evidence for the specific dosing of valacyclovir 1.5 g twice daily is the 2007 study 2.