From the Guidelines
For the treatment of HSV-2 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 three times daily to complete a 14-day course. This dose is suggested based on the most recent evidence from 2022, which emphasizes the importance of distinguishing between HSV meningitis and encephalitis, as the latter requires a longer treatment course of 14-21 days of IV acyclovir 1. The treatment regimen for HSV-2 meningitis is crucial in reducing morbidity and mortality, and improving quality of life. Key considerations in treatment include:
- Initiating treatment as soon as HSV meningitis is suspected to improve outcomes
- Monitoring renal function and maintaining adequate hydration during treatment to minimize the risk of nephrotoxicity
- Distinguishing between HSV meningitis and encephalitis to ensure appropriate treatment duration
- Using oral therapy for the entire course in persons with established recurrent HSV-2 meningitis, as IV therapy may not be necessary in these cases 1.
From the Research
Dose of Acyclovir for Meningitis
- The dose of acyclovir for meningitis is not uniformly defined, but studies provide some insight into the treatment regimens used 2, 3, 4.
- In one study, the daily dose of intravenous acyclovir ranged from 500 to 1,000 mg, with a total dose range from 500 mg q8h for 3 days to 800 mg q8h for 14 days for the first meningitic episode 2.
- For subsequent episodes, the duration of treatment with intravenous acyclovir ranged from less than 1 to 14 days, with a total dose range from 1,390 mg for 1 day to 900 mg q8h for 10 days 2.
- Another study reported the use of intravenous acyclovir, but did not specify the dose 3.
- A survey of infectious diseases specialists found that the median total duration of treatment was reported to be 7 days, regardless of antiviral regimen, with intravenous acyclovir followed by oral valacyclovir being the favored treatment in 61% of respondents 4.
Comparison with Other Antiviral Agents
- Valacyclovir has been studied as an alternative to acyclovir for the treatment of herpes simplex virus type 2 meningitis, with some studies suggesting that it may be effective in reducing the risk of recurrence 5.
- However, the optimal dose and duration of valacyclovir treatment are not well established, and one study found that suppressive treatment with 0.5 g of valacyclovir twice daily did not prohibit recurrent meningitis 5.
- Other antiviral agents, such as famciclovir, have also been studied for the treatment of herpes virus infections, but their use in meningitis is not well established 6.