The efficacy and safety of 50 mg penicillin G potassium troches for recurrent aphthous ulcers

Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2003 Dec;96(6):685-94. doi: 10.1016/j.tripleo.2003.08.024.


Purpose: To determine both the efficacy and safety of the topical application of 50 mg penicillin G potassium troches (Cankercillin) in the treatment of minor recurrent aphthous stomatitis (RAS).

Study design: The investigation used a phase 2 double-blind, randomized placebo-controlled trial with a no-treatment arm. Subjects with minor aphthous ulcers of duration <48 hours were followed for 1 week. The primary endpoint for efficacy was time (days) to complete ulcer resolution, and the secondary endpoint was time (days) to complete pain relief.

Results: Thirty-one, 33, and 36 subjects were randomized to the active treatment, placebo, and no-treatment arms, respectively. Baseline findings were heterogeneous across arms. Subjects who received penicillin G treatment had complete ulcer healing and pain relief significantly earlier than those in the placebo and no-treatment arms. No allergic reactions were observed.

Conclusions: Topical penicillin G, by mechanisms which remain unclear, reduces the time of healing and pain relief of minor aphthous ulcers with minimal safety concerns. Larger phase 3 studies are necessary to confirm these findings.

Publication types

  • Clinical Trial
  • Clinical Trial, Phase II
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Topical
  • Adolescent
  • Adult
  • Analysis of Variance
  • Anti-Bacterial Agents / administration & dosage
  • Anti-Bacterial Agents / therapeutic use*
  • Double-Blind Method
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Pain Measurement
  • Penicillin G / administration & dosage
  • Penicillin G / therapeutic use*
  • Placebos
  • Proportional Hazards Models
  • Recurrence
  • Safety
  • Stomatitis, Aphthous / drug therapy*
  • Stomatitis, Aphthous / prevention & control
  • Treatment Outcome
  • Wound Healing / drug effects


  • Anti-Bacterial Agents
  • Placebos
  • Penicillin G