Severity of baseline pain and degree of analgesia in the third molar post-extraction dental pain model

The purpose of this study was to determine whether different levels of pain would respond similarly to analgesia. We compared the analgesic response to ibuprofen in subjects with moderate versus severe baseline pain in clinical trials using the third molar post-extraction dental pain model. We performed a pooled raw data analysis of 517 subjects included in the ibuprofen treatment arm of 11 similar studies submitted to the Food and Drug Administration. The inclusion and exclusion criteria were similar in all studies. All studies used the same metrics and recorded pain at the same times. As expected, the well established analgesic effect of ibuprofen was confirmed. More intense baseline pain was initially associated with a larger decrease and greater fractional decreasing in pain intensity after medication. A larger percentage of those with milder baseline pain obtained relief compared with those with severe baseline pain. Reduction in pain intensity occurred mainly in the first 2 h. At later time points, the association of baseline conditions with a reduction in pain level diminished. We conclude that the intensity of initial pain is not correlated with the need for larger doses of analgesic.