Valacyclovir for Acute Apical Abscess Pain: A Randomized, Placebo-controlled, Double-blind Study

Acute apical abscesses are known for rapid-onset pain and swelling from pulp necrosis. While typically associated with polymicrobial infections, recent research suggests that active herpesvirus infections may also contribute. This randomized, double-blind, placebo-controlled trial aimed to evaluate if valacyclovir, when combined with amoxicillin, can consistently manage pain and how individual patients respond within a larger population.

This study enrolled 38 emergency patients with moderate to severe pain from acute apical abscesses, randomizing them into 2 treatment groups. Patients in the valacyclovir group (n = 21) received a 1g loading dose of amoxicillin (followed by 500 mg four times daily for 7 days) and a 2g loading dose of valacyclovir (followed by 500 mg twice daily for 3 days). The placebo group (n = 17) received the same amoxicillin regimen along with a placebo. Over a 6-day follow-up, we used daily phone calls to track pain levels with a numeric rating scale and monitor analgesic use. Outcome data were analyzed using the Mann-Whitney and Friedman statistical tests.

The valacyclovir group showed significantly lower mean pain scores on Days 1-3 (P < .05). They experienced a faster reduction in moderate/severe pain and a higher rate of reporting no pain (numeric rating scale= 0) throughout the study. Analgesic use dropped sharply in the valacyclovir group, with only 28.6% using analgesics on Day 1 compared to 82.4% in the placebo group. This consistently lower usage was maintained through Day 6.

Valacyclovir shows promise as an adjunctive therapy for early pain relief in patients with acute apical abscesses.