A double-blind, single-dose comparison of the analgesic efficacy of tramadol/acetaminophen combination tablets, hydrocodone/acetaminophen combination tablets, and placebo after oral surgery

Abstract

Background: Improved clinical outcomes have been documented with combinations of oral analgesic agents, particularly those with complementary activities. However, because not all combinations or dose ratios lead to enhanced analgesia or reduced adverse events (AEs), each combination and dose ratio must be evaluated individually in carefully designed preclinical and clinical trials.Objective: The goal of the study was to compare the efficacy and safety of 37.5 mg tramadol/325 mg acetaminophen tablets (T/APAP), 10 mg hydrocodone bitartrate/ 650 mg acetaminophen tablets (HC/APAP), and placebo in the treatment of postoperative dental pain.Methods: This was a single-center, double-blind, parallel-group, placebo- and active-controlled study in adults with at least moderate pain (score ≥50 on a 100-mm pain visual analog scale) after extraction of ≥2 impacted third molars. Patients were randomized to receive 1 or 2 T/APAP tablets, 1 HC/APAP tablet, or placebo. Scores for hourly pain relief (PAR), pain intensity difference (PID), and combined PAR and PID (PRID) were based on reported pain at 30 minutes and each successive hour for 8 hours. Primary efficacy measures were summary pain intensity and pain relief scores (total pain relief [TOTPAR], sum of pain intensity differences [SPID], and sum of pain relief and pain intensity differences [SPRID]) for 0 to 4 hours, 4 to 8 hours, and 0 to 8 hours. Secondary efficacy measures were hourly PAR, PID, and PRID scores; onset and duration of pain relief; time to remedication with a supplemental analgesic agent; and patients' overall assessment of medication.Results: Two hundred adults took part in the study (50 per treatment group) and were included in the efficacy and safety analyses. T/APAP 75/650 mg and HC/APAP were statistically superior to placebo on the primary efficacy measures of TOTPAR, SPID, and SPRID (P ≤ 0.024), as well as on hourly PAR, PID, and PRID over 6 hours (P ≤ 0.045). All active treatments were statistically superior to placebo in terms of onset of pain relief (P ≤ 0.001), duration of pain relief (P ≤ 0.024), time to remedication (P < 0.001), and patients' overall assessment of medication (P < 0.001). A statistically significant dose response with T/APAP (2 tablets > 1 tablet > placebo) was seen for TOTPAR, SPID, and SPRID (all, P ≤ 0.018). The median time to on-set of pain relief was ∼34.0 minutes with 2 T/APAP tablets and 25.4 minutes with HC/APAP. Although the median time to onset of pain relief was shorter with HC/APAP, two T/APAP tablets had comparable efficacy to HC/APAP. The median time to remedication with a supplemental analgesic agent was 169.0 minutes in the T/APAP 75/650 mg group and 204.0 minutes in the HC/APAP group. However, the duration of pain relief, as defined by time to remedication, was not significantly different between these 2 groups. The overall incidence of AEs was lower with T/APAP (0% treatment-related AEs) than with HC/APAP (4%) or placebo (10%). The incidence of nausea (18% T/APAP, 36% HC/APAP) and vomiting (12% T/APAP, 30% HC/APAP) was ∼50% lower with 2 T/APAP tablets than with HC/APAP (P < 0.05).Conclusions: T/APAP tablets provided effective, rapid (≤34 minutes), dose-dependent analgesia for the treatment of postoperative dental pain. Two T/APAP tablets provided analgesia comparable to that provided by HC/APAP with better tolerability.