Phenazone versus placebo: effects on post-operative course.

In a double-blind crossover study essentially the same operation was performed twice in 24 patients who required surgical removal of bilateral "identically" impacted wisdom teeth. On one occasion they were given phenazone (1.0 g X 4 for 2 days, then 0.5 g X 4 for the next 2 days), on the other placebo tablets. Several objective and subjective assessments were recorded to permit paired comparison of the post-operative courses. Swelling on the 3rd day after the operation when phenazone was given averaged 82% of that when placebo was used (p > 0.10). The local temperature increase was somewhat reduced with phenazone (0.72 vs 1.10 degrees C) and there was a smaller reduction in mouth-opening ability (29 vs 41%), but there was a tendency towards a slightly greater post-operative bleeding score with the drug. Significant pain relief was obtained with phenazone according to assessment both by fixed interval scores and a visual analogue scale. Although nausea was experienced by some of the patients when given phenazone (possibly related to the rather high dose), the preference scores were clearly in favour of the drug. Compared to results previously obtained in this model, phenazone may be preferable to acetylsalicylic acid in oral surgery, but phenazone does not compare favourably with the results obtained with paracetamol.