The efficacy and pharmacokinetics of sodium salicylate in post-operative dental pain

Comparison of Pain Levels With Postoperative Intramuscular Administration of Single-Dose Ketoprofen Versus Diclofenac Sodium in Patients Undergoing Lower Third Molar Surgery

Background Third molar surgeries are commonly performed in oral and maxillofacial surgery practice. Pain associated with this procedure is usually a frequent reason for patient apprehension and discomfort. Oral analgesics, though effective, do not provide sufficient pain relief in the immediate postoperative period.  Aim To assess the postoperative effect on pain levels of single-dose administration of ketoprofen and diclofenac sodium as an injection in patients undergoing third molar removal surgeries.  Methods This study was conducted among 30 patients divided into two groups (n=15). Patients in Group K received injection ketoprofen 100 mg and Group D included patients receiving injection diclofenac sodium 75 mg, both intramuscularly postoperatively. The intensity of pain was assessed at 30 minutes, two, six, and eight hours post-surgical removal of the impacted tooth using the visual analogue scale (VAS). The statistical data was analyzed using SPSS for Windows version 23.0 (IBM Corp., Armonk, NY, USA). The comparative statistical test adopted to compare pain scores between the two groups was the Independent samples t-test. A p-value of <0.05 was considered to be statistically significant. Results Our study results revealed that Group K patient's VAS scores after two hours, six hours, and eight hours were 3.9 ± 2.7, 4.5 ± 3.23, 2.93 ± 2.27 respectively. In Group D patient's VAS scores after two hours, six hours, and eight hours were 4.83 ± 2.82, 5.03 ± 2.9, 3.73 ± 2.91 respectively. Patients who were administered ketoprofen had lower pain levels when compared to patients who were given diclofenac but the difference was not statistically significant at any time point (p=0.172 after eight hours). Our results depicted that the pain levels uniformly reached their maximal levels six hours after the procedure and thereafter steadily declined in both groups.  Conclusion It can be concluded from the study that both the drugs ketoprofen and diclofenac sodium analyzed in this study can be used interchangeably for the reduction of pain following lower third molar surgery.

Non-steroidal anti-inflammatory drugs and spinal nociceptive processing

Non-steroidal anti-inflammatory drugs have a direct action on spinal nociceptive processing in vivo with a relative order of potency which correlates with their capacity as inhibitors of cyclooxygenase activity. However, recent clinical surveys and new in vivo evidence strongly suggest that for some of these agents, centrally mediated analgesia may also be achieved by additional mechanisms, which are independent of prostaglandin synthesis inhibition. In this review we explore the likelihood for such mechanisms following an extensive survey of existing data. The implications of these mechanisms are discussed in the light of our current understanding of spinal nociceptive processing.

Comparison of Controlled-Release Ketoprofen and Diclofenac in the Control of Post-Surgical Dental Pain

Preoperative treatment with controlled-release ketoprofen or diclofenac was compared in 56 outpatients, for control of postoperative dental pain, following unilateral or bilateral surgical removal of lower third molars. Six patients were excluded due to non-compliance, leaving 50 evaluable patients.

Patients were assessed by the dental surgeon, on the day of the operation and one week later, prior to removal of sutures. Additionally, patients completed a daily diary during the postoperative week. Following surgery, scores for graded dental pain, consumption of paracetamol, incidence of dental bleeding, dysphagia, sleep disturbance and trismus were similar for the two treatment groups. However, median pain scores were consistently elevated in the diclofenac group over those seen with the ketoprofen group. The four adverse events reported were all minor and posed no problem to patient management.

The efficacy of benorylate in postoperative dental pain

The efficacy of a single pre-operative dose of benorylate (4 g) was determined in a double-blind, randomized, placebo-controlled parallel study in patients undergoing removal of a single impacted lower third molar. Patients treated with benorylate 4 g reported significantly less pain between 3-6 h after dosage than those treated with placebo. Overall pain scores at 6 h were significantly less in the benorylate group than the placebo group. However, overall pain scores at 12 h did not differ significantly between treatment groups. It is concluded from this study that a single dose of benorylate 4 g given immediately prior to the removal of an impacted lower third molar provides limited pain control during the postoperative period.

Measurement of the analgesic effects of aspirin with a new experimental algesimetric procedure

Using controlled long lasting noxious squeeze stimuli applied to the interdigital webs we have tried to develop experimental methods allowing us to measure the effects of peripherally acting analgesics. In the present double-blind cross-over study with 12 subjects we tested the effects of aspirin (1000 and 1500 mg) vs. placebo on subjective pain induced by alternately applied 12 N (Newton) and 8 N stimuli. During the sessions blood samples were taken in regular intervals to measure acetylsalicylate (ASA)- and salicylate (SA)-plasma levels. Analyses of variance were computed with several psychophysical parameters. Both the '12 N' and the '8 N' ratings discriminated between placebo and aspirin, however, only the ratings obtained from the stronger stimuli discriminated between two doses of aspirin. Subsequently we computed analyses of covariance with the ASA- and SA-plasma levels as covariates. Significant (negative) correlations of pain ratings and SA-plasma levels were found for the high dose of aspirin, but there were no significant correlations of ASA levels and ratings.

A double-blind, randomized study of naproxen and acetylsalicylic acid after surgical removal of impacted lower third molars

100 patients had an impacted lower 3rd molar surgically removed in a double-blind study. Naproxen (500 mg b.i.d.) or acetylsalicylic acid (ASA) (1 g t.i.d.) were administered to the patients. Paracetamol was allowed as escape medication. 49 patients received naproxen and 51 ASA. 4 patients from each group were excluded because they took other analgesics, took too few tablets, were lost to follow-up or had misunderstood the instructions. There was a significantly better over all analgesic effect of naproxen than ASA (p = 0.004). More patients in the naproxen group than in the ASA group (p less than 0.01) would accept treatment with the same drug again. 4 patients, all from the ASA group, complained spontaneously about side effects.

Aspirin and related derivatives of salicylic acid

After almost 90 years of clinical use, aspirin remains one of the world's most extensively used 'over-the-counter' drugs, and it is still recognised as the standard analgesic/antipyretic/anti-inflammatory agent by which newer drugs are assessed. However, its pre-eminent position as the analgesic of choice for mild to moderate pain has been seriously challenged with the introduction of many 'new' non-steroidal non-narcotic analgesic drugs. Indeed, there is convincing scientific evidence that many of the 'newer' non-steroidal drugs such as diflunisal, ibuprofen, flurbiprofen etc. are significantly superior analgesics and, in many cases, have a longer duration of action. In recent years the salicylates, aspirin in particular, have been the focus of much attention regarding their side effect profiles. At usual dosages for relief of pain and during occasional use, aspirin is well tolerated by the vast majority of patients. Adverse reactions, of which there is a wide spectrum, most frequently accompany anti-inflammatory doses of aspirin, or may be the result of accidental overdosing (particularly in children and the elderly)--probably a reflection of the lay population's acceptability of aspirin's presumed safety. As with other non-steroidal analgesic drugs, gastrointestinal complaints are the most commonly reported side effects. The existence of many shared clinical, adverse and toxic effects of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) is thought to be accounted for by a common mechanism--inhibition of the ubiquitous cyclo-oxygenase enzyme. Thus, suppression of prostaglandin biosynthesis is widely considered to explain the common properties of NSAIDS, although further research is still necessary to clarify some inconsistencies and to complete our understanding of the processes involved. Aspirin and salicylates have been reported to have a wide range of drug interactions but only relatively few seem to be clinically important. Many of the interactions are pharmacokinetic in nature. Drugs considered to produce the most significant interactions with salicylates include anticoagulants and thrombolytic agents, uricosuric agents, corticosteroids, methotrexate and sulphonylurea hypoglycaemic agents.

Clinical significance of esterases in man

Esterases, hydrolases which split ester bonds, hydrolyse a number of compounds used as drugs in humans. The enzymes involved are classified broadly as cholinesterases (including acetylcholinesterase), carboxylesterases, and arylesterases, but apart from acetylcholinesterase, their biological function is unknown. The acetylcholinesterase present in nerve endings involved in neurotransmission is inhibited by anticholinesterase drugs, e.g. neostigmine, and by organophosphorous compounds (mainly insecticides). Cholinesterases are primarily involved in drug hydrolysis in the plasma, arylesterases in the plasma and red blood cells, and carboxylesterases in the liver, gut and other tissues. The esterases exhibit specificities for certain substrates and inhibitors but a drug is often hydrolysed by more than one esterase at different sites. Aspirin (acetylsalicylic acid), for example, is hydrolysed to salicylate by carboxylesterases in the liver during the first-pass. Only 60% of an oral dose reaches the systemic circulation where it is hydrolysed by plasma cholinesterases and albumin and red blood cell arylesterases. Thus, the concentration of aspirin relative to salicylate in the circulation may be affected by individual variation in esterase levels and the relative roles of the different esterases, and this may influence the overall pharmacological effect. Other drugs have been less extensively investigated than aspirin and these include heroin (diacetylmorphine), suxamethonium (succinylcholine), clofibrate, carbimazole, procaine and other local anaesthetics. Ester prodrugs are widely used to improve absorption of drugs and in depot preparations. The active drug is released by hydrolysis by tissue carboxylesterases. Individual differences in esterase activity may be genetically determined, as is the case with atypical cholinesterases and the polymorphic distribution of serum paraoxonase and red blood cell esterase D. Disease states may also alter esterase activity.

Use of analgesics in postoperative dental pain: a review

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Aspirin metabolism and efficacy in postoperative dental pain

Aspirin 1200 mg was compared with placebo in a randomised, double-blind, crossover study in 15 patients with postoperative pain after removal of impacted lower third molars. Over a 5 h investigation period, patients reported significantly less pain (P less than 0.01) after treatment with aspirin, than after treatment with placebo. Peak concentrations of aspirin occurred at 15 min after dosage. Significant negative correlations were observed between plasma aspirin esterase activity and both AUC aspirin (r = -0.904, P less than 0.001) and AUC analgesia (r = -0.91, P less than 0.001). Similarly, a significant correlation was observed between AUC aspirin and AUC analgesia (r = 0.96, P less than 0.001). Evidence from this study would suggest that an individual's pain relief in postoperative dental pain is determined by the rate of aspirin hydrolysis to salicylate.