What is the prophylactic dose of Aciclovir (acyclovir) in a patient undergoing chemotherapy?

From the Guidelines

Acyclovir prophylaxis for patients undergoing chemotherapy should be administered at a dose of 200 mg by mouth three times daily or 400 mg every 12 hours, as recommended by the guidelines for preventing opportunistic infections among HIV-infected persons 1.

Key Considerations

• The dose may need to be adjusted for patients with renal impairment, with reductions based on creatinine clearance, as outlined in the guidelines 1.
• Acyclovir prophylaxis is particularly important for patients with a history of herpes simplex virus (HSV) or varicella-zoster virus (VZV) infections, as chemotherapy-induced immunosuppression can lead to viral reactivation.
• The medication works by inhibiting viral DNA polymerase, preventing viral replication in infected cells.
• Common side effects include nausea, headache, and diarrhea, while adequate hydration should be maintained to prevent crystalluria.
• Regular monitoring of renal function is recommended during treatment.

Additional Recommendations

• According to the antimicrobial prophylaxis for adult patients with cancer-related immunosuppression guidelines, herpes simplex virus–seropositive patients undergoing allogeneic HSCT or leukemia induction therapy should receive prophylaxis with a nucleoside analog (eg, acyclovir) 1.
• The guidelines also recommend yearly influenza vaccination with inactivated vaccine for all patients receiving chemotherapy for malignancy and all family and household contacts and health care providers 1.

From the Research

Aciclovir Prophylaxis Dose in Patients with Chemotherapy

• The dose of aciclovir prophylaxis in patients with chemotherapy is not directly stated in the provided studies, but valaciclovir, an aciclovir pro-drug, has been studied as an alternative 2, 3.
• Valaciclovir has improved bioavailability compared to aciclovir, with a mean absolute bioavailability of 54.2% after a single oral dose of 1,000 mg 2.
• In patients with leukemia, valaciclovir at doses of 500 mg or 1,000 mg orally every 8 hours has been shown to be effective in preventing herpes simplex virus reactivation during high-dose chemotherapy 3.
• The pharmacokinetic parameters of valaciclovir in patients with agranulocytosis following poly-chemotherapy are similar to those in healthy patients, suggesting that dose adjustment may not be necessary in this population 2.
• However, the dose of valaciclovir should be adapted to renal function, as exposure to aciclovir is enhanced in patients with impaired renal function 2.
• In terms of chemotherapy-related nephrotoxicity, conventional chemotherapies can cause kidney complications, including acute kidney injury and long-term kidney function loss 4.
• The use of prophylactic antibiotics during neutropenia to reduce the risk of infection has been investigated, and fluoroquinolone prophylaxis has been shown to be effective in reducing febrile neutropenia episodes and hospitalization for infection treatment 5.

Key Findings

• Valaciclovir is an effective alternative to aciclovir for prophylaxis against herpes simplex virus reactivation during chemotherapy 3.
• The dose of valaciclovir should be adapted to renal function, but not necessarily to chemotherapy-related agranulocytosis 2.
• Chemotherapy-related nephrotoxicity is a significant concern, and strategies for kidney risk mitigation are necessary 4.
• Prophylactic antibiotics, such as fluoroquinolones, may be effective in reducing the risk of infection during neutropenia, but their use should be guided by a secure evidence base 5.