Dosing Practices of Intravenous Acyclovir for Herpes Encephalitis in Obesity: Results of a Pharmacist Survey.

BACKGROUND

Dosing of intravenous acyclovir for herpes encephalitis in obese patients is recommended to be based on ideal body weight. However, limited data support this recommendation, and recent data suggest this may lead to underdosing.

OBJECTIVE

To determine national dosing practices of intravenous acyclovir across a range of patient weights.

METHODS

A survey was distributed to members of the American College of Clinical Pharmacy Critical Care and Infectious Diseases Practice & Research Networks listservs. Data collected included demographic information and dosing of acyclovir, given consistent patient cases with varying patient weight.

RESULTS

A total of 264 pharmacists participated in the survey, with 240 (90.9%) participants completing the survey. Participants were predominately clinical pharmacists. As patient weight increased, respondents were more apt to dose based on an adjusted body weight, with dosing in the obese and morbidly obese showing a clear lack of consistency.

CONCLUSIONS

Intravenous dosing of acyclovir for herpes encephalitis is variable, especially in obese patients, and does not reflect recommendations. Limited data provide conflicting recommendations for dosing in obese patients, and future studies are necessary to optimize patient outcomes and prevent toxicity.