What is the dose of acyclovir (antiviral medication) for viral meningitis in a 14-year-old male patient weighing 40 kilograms?

From the Guidelines

For a 14-year-old boy weighing 40 kg with meningitis, the recommended dose of acyclovir is 10 mg/kg intravenously every 8 hours until resolution of fever and headache, followed by valacyclovir 1 g TID to complete a 14-day course, as suggested by the most recent evidence 1.

Key Considerations

• The dose of acyclovir should be calculated based on the patient's weight, which in this case is 40 kg, resulting in a dose of approximately 400 mg per dose, administered three times daily.
• The medication should be infused over 1 hour to avoid renal toxicity, and adequate hydration should be maintained throughout treatment to protect kidney function.
• Acyclovir works by inhibiting viral DNA synthesis, particularly effective against herpes simplex virus (HSV) and varicella-zoster virus (VZV), which are common causes of viral meningitis.
• Renal function should be monitored during treatment, and dose adjustments may be necessary if kidney function becomes impaired.
• Treatment should begin as soon as viral meningitis is suspected, as early intervention improves outcomes.

Important Distinctions

• It is essential to distinguish cases of HSV encephalitis from HSV meningitis, as HSV encephalitis is a much more severe infection with high neurologic morbidity and mortality, and should be treated with 14–21 days of IV acyclovir 1.
• The recommended dose and treatment duration may vary depending on the specific diagnosis and clinical presentation, and should be guided by the most recent and highest-quality evidence available.

Clinical Application

• In clinical practice, the treatment of viral meningitis should be individualized based on the patient's specific needs and circumstances, taking into account factors such as renal function, hydration status, and potential drug interactions.
• The use of valacyclovir as an alternative to acyclovir may be considered in certain cases, such as recurrent HSV-2 meningitis, but the dose and treatment duration should be guided by the most recent evidence 1.

From the FDA Drug Label

Herpes Simplex Encephalitis Sixty-two patients ages 6 months to 79 years with brain biopsy-proven herpes simplex encephalitis were randomized to receive either acyclovir (10 mg/kg every 8 hours) or vidarabine (15 mg/kg/day) for 10 days

• The dose of acyclovir for a 14-year-old boy weighing 40 kg with meningitis is 10 mg/kg every 8 hours.
• This dose is based on the treatment of herpes simplex encephalitis, which is a similar condition to meningitis.
• The patient's weight is 40 kg, so the dose would be 400 mg every 8 hours 2.

From the Research

Acyclovir Dosage for Meningitis

The dosage of acyclovir for a 14-year-old boy weighing 40 kg with meningitis is not explicitly stated in the provided studies.

Relevant Studies

• The study 3 compared empiric antibiotic and acyclovir usage before and after the introduction of an on-site FilmArray Meningitis/Encephalitis Panel in a pediatric hospital, but it does not provide information on the dosage of acyclovir.
• The study 4 reviewed the clinical and cost implications of Biofire FilmArray® meningitis/encephalitis panel testing, but it also does not provide information on the dosage of acyclovir.
• The study 5 reviewed empiric acyclovir prescribing practices for suspected viral central nervous system infections, but it does not provide information on the dosage of acyclovir.
• The study 6 evaluated the role of viral polymerase chain reaction testing in patients with aseptic meningitis, but it does not provide information on the dosage of acyclovir.
• The study 7 studied the impact of a 24/7 multiplex-PCR on the management of patients with confirmed viral meningitis, but it does not provide information on the dosage of acyclovir.

Key Points

• None of the provided studies mention the specific dosage of acyclovir for a 14-year-old boy weighing 40 kg with meningitis.
• The studies focus on the usage, duration, and reduction of acyclovir treatment in patients with suspected or confirmed meningitis, but do not provide dosage information.
• To determine the appropriate dosage of acyclovir, it is recommended to consult a medical professional or refer to established clinical guidelines.