A placebo-controlled comparative evaluation of diclofenac dispersible versus ibuprofen in postoperative pain after third molar surgery.

The analgesic efficacy of single oral doses of drinkable diclofenac dispersible 50 mg was compared with that of ibuprofen 400 mg and placebo in a randomized, double-blind, parallel-group trial in 257 adult patients (245 valid for efficacy) with severe postoperative pain after extraction of an impacted lower third molar. In this study, pain intensity (on a 100-mm visual analog scale) and pain relief from baseline (using a five-point verbal rating scale) were assessed serially during an observation period of 6 hours. Intake of rescue analgesic was permitted in case of insufficient therapeutic effect; however at least 1 hour should have elapsed after test drug consumption. On the main efficacy variable, namely, reduction in the pain intensity score, both diclofenac dispersible (n = 83) and ibuprofen (n = 80) were statistically significantly (P < .01) superior to placebo (n = 82) starting at 20 and 40 minutes, respectively, after drug intake. The active medications were also significantly (P < .01) better than placebo for the secondary efficacy parameters viz. summed pain relief scores over 6 hours (TOTPAR-6); frequency of remedication with a rescue analgesic in the three treatment groups (diclofenac, 24%; ibuprofen, 28%; placebo, 65%); mean time to remedication; and global evaluation. All the treatments were well tolerated. Thus assay sensitivity of this trial (ibuprofen significantly better than placebo) has been demonstrated; in addition, diclofenac as a dispersible formulation has been shown to be an effective analgesic for the treatment of post-surgical dental pain.

Pharmacokinetics of diclofenac and five metabolites after single doses in healthy volunteers and after repeated doses in patients.

1. The kinetics of diclofenac (I) and five of its metabolites (II-VI) were investigated in three healthy volunteers and in six patients. Compounds I-VI were measured by capillary column gas chromatography in plasma and urine. 2. After a single 100 mg dose of diclofenac sodium to volunteers, the drug was absorbed rapidly and showed peak plasma levels of 10-12 nmol/g. The maximum concentrations of five metabolites were comparatively low (0.36-2.94 nmol/g). The mono- and dihydroxy metabolites (II-V) had apparent terminal half-lives similar to that of I (1-3 h), but the hydroxymethoxy metabolite (VI) had a half-life of about 80 h. Renal elimination of VI within 96 h was about 1% of dose and that of I-VI was 36% (free plus conjugated). 3. Following daily treatment with 2 x 75 mg of an experimental sustained release formulation to patients for 6-10 months, steady-state trough concentrations of I-V in plasma were low (average values: 0.23-0.57 nmol/g). The mean trough concentration of VI was comparatively higher at 3.69 +/- 0.91 nmol/g presumably reflecting its accumulation. Despite this it is unlikely to contribute to the drug's therapeutic activity, since it has been shown in laboratory tests to be devoid of anti-inflammatory activity.