What is the first antimicrobial agent that should be administered to a 17-day-old neonate showing symptoms consistent with herpes simplex virus (HSV) encephalitis?

Administering Acyclovir as an IV infusion over 60 minutes is the appropriate choice for a 17-day-old neonate exhibiting symptoms suggestive of herpes simplex virus (HSV) encephalitis. Acyclovir is an antiviral medication specifically used to treat infections caused by certain types of viruses, including HSV. In neonates, prompt administration of Acyclovir is crucial because neonatal HSV infections can lead to serious complications, including neurological damage or death if not treated promptly.

The recommended dosing for Acyclovir in neonates is based on weight and is given as a prolonged infusion to minimize the risk of nephrotoxicity and ensure adequate plasma levels of the drug. The 60-minute infusion allows for better tolerance of the medication and maximizes efficacy against the virus.

In this clinical scenario, the other options do not provide effective treatment for suspected HSV encephalitis. For instance, Gentamicin and Ampicillin are antibiotics that target bacterial infections, which are not suitable for a viral infection like HSV. Moreover, while the IV push with Acyclovir might seem effective, the rapid administration over 5 minutes does not align with the best practices for neonatal dosing where infusion over a longer time frame is recommended to avoid potential side effects and to improve