From the Guidelines
Valacyclovir is recommended as antiviral prophylaxis for multiple myeloma patients receiving proteasome inhibitors, with a standard prophylactic dose of 500 mg orally once daily. This recommendation is based on the increased risk of herpes zoster reactivation in multiple myeloma patients, particularly those on proteasome inhibitors which impair T-cell immunity, as noted in the study by 1. The use of valacyclovir as prophylaxis is supported by its better bioavailability and less frequent dosing compared to acyclovir.
Key Considerations
- Prophylaxis should begin with proteasome inhibitor therapy and continue for the duration of treatment, typically extending 4-6 weeks after discontinuation.
- For patients with renal impairment, dose adjustment is necessary: 500 mg every 48 hours for creatinine clearance 10-29 mL/min and 500 mg every 72 hours for clearance below 10 mL/min.
- Alternative options include acyclovir 400 mg twice daily or famciclovir 250 mg daily if valacyclovir is unavailable or not tolerated.
- The recommendation for valacyclovir prophylaxis is also supported by guidelines from the European Myeloma Network, as seen in 2, which emphasize the importance of preventing infections in multiple myeloma patients.
Rationale
The rationale for using valacyclovir as antiviral prophylaxis in multiple myeloma patients is to prevent herpes zoster reactivation, which can occur at a higher rate in these patients due to impaired T-cell immunity. By preventing herpes zoster reactivation, valacyclovir can help reduce the risk of complications and improve quality of life for multiple myeloma patients. This is in line with the goal of minimizing morbidity, mortality, and improving quality of life, as prioritized in clinical decision-making.
Additional Guidance
It's worth noting that while valacyclovir is the preferred antiviral prophylaxis, other options like acyclovir or famciclovir may be considered based on patient-specific factors or availability. However, the choice of antiviral prophylaxis should always prioritize the prevention of herpes zoster reactivation and its associated complications. As indicated by 3, the management of multiple myeloma-related complications, including infections, is crucial for improving patient outcomes.
From the Research
Valacyclovir in Multiple Myeloma
- Valacyclovir is used as a prophylactic measure to prevent Varicella zoster virus (VZV) reactivation in multiple myeloma patients receiving bortezomib therapy 4, 5.
- A study found that daily 500 mg valacyclovir is effective for prevention of VZV reactivation in patients with multiple myeloma treated with bortezomib, with only one patient developing VZV reactivation during valacyclovir prophylaxis 5.
- Another study used valacyclovir as an alternative to acyclovir, with a dose of 250/500 mg administered daily, and found no episodes of herpes zoster during the treatment period 4.
Efficacy and Safety
- Valacyclovir at a dose of 500 mg daily appears to be effective at preventing VZV reactivation and was well-tolerated by patients with multiple myeloma who received bortezomib 5.
- No adverse effects were noted that could be definitely attributed to valacyclovir in the studies 4, 5.
- The use of antiviral agents, including valacyclovir, is a predictive factor for varicella-zoster virus reactivation, and prophylaxis is essential for treating newly diagnosed multiple myeloma patients 6.
Comparison with Other Antiviral Agents
- Valacyclovir has been compared to acyclovir and famciclovir in terms of efficacy and safety, with similar protective effects observed 6, 7.
- Intermittent famciclovir prophylaxis has been found to be effective and safe in preventing herpes zoster development, and can markedly reduce the duration of oral medicine treatment compared with continuous acyclovir prophylaxis 7.