Valacyclovir in Pain Management of Acute Apical Abscesses: A Randomized Placebo-Controlled Double-Blind Pilot Study.

Introduction: The acute (symptomatic) apical abscess is characterized by pulp necrosis, rapid onset, spontaneous pain, percussion pain, pus formation, and tissue swelling. The etiopathology of acute apical abscesses includes active (lytic) herpesviruses and gram-negative anaerobic bacteria. The present study examined the potential of valacyclovir, an anti-herpesvirus agent, and systemic amoxicillin to manage the pain of acute apical abscesses.

Methods: Twenty emergency patients with moderate to severe apical abscess pain received randomly either amoxicillin (1 g immediate dose followed by 500 mg, 4 times a day, totally 7 days) + valacyclovir (2 g immediate dose followed by 500 mg, twice a day, totally 3 days) ("valacyclovir" group, 10 patients) OR amoxicillin (1 g immediate dose followed by 500 mg, 4 times a day, totally 7 days) + placebo ("placebo" group, 10 patients). Daily telephone calls during the 6-day follow-up period assessed pain level on a numeric rating scale and analgesic intake. The Mann-Whitney and the Friedman statistical tests analyzed the outcome data.

Results: At the baseline examination, all 10 valacyclovir and 9 placebo patients exhibited moderate to severe pain and 18 patients needed pain medication. On the first day after baseline, the valacyclovir group showed 2 patients with moderate/severe pain and 1 patient on pain medication, but the placebo group revealed as many as 8 patients with moderate/severe pain and 9 patients on pain medication. The difference in pain level and analgesic usage between the valacyclovir and the placebo group remained statistically significant during the entire post-baseline study period (P < .05).

Conclusion: The present study points to valacyclovir as a promising adjunctive agent in pain control with acute apical abscesses.