What is the treatment for oral herpes (Herpes Simplex Virus, HSV) in a child using Acyclovir (antiviral medication)?

From the Guidelines

Acyclovir is recommended for the treatment of oral herpes in children, with a dosage of 20 mg/kg body weight (max 400 mg/dose) per dose orally 3 times daily for 5--10 days. This recommendation is based on the guidelines from the CDC, the National Institutes of Health, and other reputable organizations, as outlined in the study published in MMWR Recommendations and Reports 1.

Key Considerations

• The medication is most effective when started at the first sign of symptoms, and it works by inhibiting viral DNA replication, preventing the herpes simplex virus from multiplying.
• Common side effects may include nausea, vomiting, headache, or diarrhea, and children should be encouraged to stay well-hydrated while taking the medication.
• It is essential to practice good hygiene, such as avoiding sharing utensils, towels, or direct contact with the sores, to prevent spreading the infection.

Special Populations

• For children under 2 years, it is recommended to consult a pediatrician for appropriate dosing, as the study does not provide specific guidance for this age group.
• If the child has kidney problems or is taking other medications, it is crucial to inform the doctor before starting acyclovir, as this may affect the dosage or increase the risk of side effects.

Additional Management

• Over-the-counter pain relievers like acetaminophen or ibuprofen can help manage discomfort while the medication takes effect.
• For recurrent episodes, some children may benefit from prophylactic therapy, but this should be discussed with a healthcare provider, as the study does not provide clear guidance on this topic.

From the Research

Acyclovir for Oral Herpes in Children

• Acyclovir is approved for the treatment of herpes simplex virus (HSV) and varicella-zoster virus (VZV) infections in children by the intravenous and oral routes 2.
• The use of oral acyclovir in children younger than 2 years of age is limited due to a lack of pharmacokinetic data, but a study found that the proposed dosing regimen of 24 mg/kg of body weight three times a day for patients younger than 1 month of age or four times a day otherwise seems adequate for the treatment of HSV infections 2.
• For the treatment of VZV infections, a twofold increase in the dose seems necessary for children older than age 3 months 2.

Efficacy of Acyclovir in Treating Herpetic Gingivostomatitis

• A randomized double-blind placebo-controlled study found that aciclovir suspension shortened the duration of oral lesions, fever, eating and drinking difficulties, and viral shedding in children with herpetic gingivostomatitis 3.
• The study suggested that oral aciclovir treatment for herpetic gingivostomatitis, started within the first three days of onset, shortens the duration of all clinical manifestations and the infectivity of affected children 3.
• Another study recommended that treatment should be started only within the first 72 hours of symptom onset if substantial pain or dehydration are documented 4.

Pharmacokinetics of Acyclovir in Children

• A study found that the bioavailability of oral acyclovir was 0.12, and the elimination half-life decreased sharply during the first month after birth, from 10 to 15 h to 2.5 h 2.
• The volume of distribution was related to body weight, and the interindividual variability was less pronounced when the parameters were normalized with respect to body weight 2.
• Another study found that valacyclovir suspension at a dose of 20 mg/kg/dose every 8 hours cannot be recommended for use in a portion of the treatment course for neonatal HSV disease due to lower bioavailability and systemic acyclovir exposure compared to parenteral acyclovir 5.

Dosing Considerations for Oral Acyclovir

• A study described nine infants who were treated with doses of oral acyclovir chosen to achieve 2-h post-plasma concentrations of > or = 2 micrograms/ml, and found that plasma concentration of acyclovir > or = 2 micrograms/ml may be achieved with average oral doses of 1340 mg/m2/dose given at 12-h intervals 6.
• The study suggested that long-term acyclovir may be used to prevent recurrent Herpes simplex disease, and that renal and neurologic status should be routinely monitored for signs of acyclovir toxicity 6.