From the Guidelines
The recommended dose of aciclovir for prophylaxis in patients undergoing allogeneic stem cell transplantation is 800 mg bid, as stated in the most recent guidelines 1. This dose is recommended to start from lymphodepleting conditioning until 1-year post-CAR T-cell infusion AND until CD4+ count >0.2 10^9/l. The choice of aciclovir over other antiviral medications such as valacyclovir is based on its established efficacy in preventing herpes simplex virus (HSV) reactivation, which is a common complication in immunocompromised transplant recipients 1. Key points to consider when administering aciclovir for prophylaxis in this patient population include:
- Monitoring renal function, as aciclovir can cause nephrotoxicity, particularly when given intravenously or in dehydrated patients
- Adjusting the dose based on creatinine clearance in patients with renal impairment
- Being aware of potential side effects, including nausea, headache, and rarely, neurological symptoms
- Considering the duration of prophylaxis, which may be extended beyond day +30 post-transplant in patients receiving immunosuppressive therapy for graft-versus-host disease. It's worth noting that while valacyclovir is also effective in preventing HSV reactivation, the most recent guidelines recommend aciclovir 800 mg bid 1.
From the Research
Aciclovir Prophylaxis in Allogenic Stem Cell Transplantation
The recommended dose of aciclovir for prophylaxis in patients undergoing allogenic stem cell transplantation varies across studies.
- A study published in 2024 2 found that oral aciclovir 400 mg taken twice daily for prophylaxis in alloSCT recipients is both effective and well-tolerated, preventing HSV and VZV reactivation without compromising efficacy or patient safety.
- Another study from 2013 3 showed that low-dose acyclovir (200 mg/day) is effective for preventing HSV disease in the early phase after HSCT.
- However, a study from 2023 4 discussed the use of high-dose aciclovir in CMV infection prophylaxis after allogeneic HSCT, but did not provide a clear recommendation for the dose of aciclovir for prophylaxis in patients undergoing allogenic stem cell transplantation.
- It's worth noting that the studies 5, 6 discussed the use of valaciclovir and other antiviral agents for prophylaxis against herpesvirus infections in transplant recipients, but did not provide specific recommendations for the dose of aciclovir.
Key Findings
- The dose of aciclovir for prophylaxis in patients undergoing allogenic stem cell transplantation is not universally agreed upon, with different studies recommending different doses.
- Low-dose acyclovir (200-400 mg/day) may be effective for preventing HSV disease in the early phase after HSCT 2, 3.
- High-dose aciclovir may be effective for CMV infection prophylaxis after allogeneic HSCT, but more research is needed to determine the optimal dose 4.