Time-contingent dosing of an opioid analgesic after tonsillectomy does not increase moderate-to-severe side effects in children.

As part of a randomized clinical trial that compared three different analgesic dosing regimens ( Sutters et al., 2004 ), the purpose of this study, in children who underwent tonsillectomy, was to determine whether around-the-clock (ATC) dosing of acetaminophen with codeine, compared with as-needed (PRN) dosing, increased the frequency of moderate-to-severe opioid-related side effects (i.e., daytime sedation, lightheadedness, nightmares, nausea, vomiting, and constipation) in the first 3 days after surgery. Because no differences were found in pain intensity scores and in the amount of analgesic administered between the two ATC groups (i.e., with and without coaching), for these analyses, the two groups were combined ( n = 52) and compared with the PRN group ( n = 28). Each side effect was recoded into a dichotomous response (i.e., 0 = did not have symptoms or had slight symptoms; 1 = symptoms that were moderate, severe, or very severe) to provide an adequate sample size in each cell for the statistical analyses. No differences were found in the frequency of moderate-to-severe side effects between the ATC and PRN groups at any of the postoperative assessments. The number of children who reported moderate-to-severe daytime sedation decreased over time in both the PRN ( p = .02) and ATC groups ( p = .01). Children in the ATC groups reported a statistically significant decrease over time in vomiting ( p = .001) and feeling lightheaded or dizzy ( p = .003), and a significant increase in constipation ( p = .018). Except for daytime sedation, changes, over time, in the frequency of moderate-to-severe side effects were not observed in the PRN group.