An investigation into the efficacy of intravenous diclofenac in post-operative dental pain

Single-dose intravenous diclofenac for acute postoperative pain in adults

BACKGROUND

Postoperative administration of non-steroidal anti-inflammatory drugs (NSAIDs) reduces patient opioid requirements and, in turn, reduces the incidence and severity of opioid-induced adverse events (AEs).

OBJECTIVES

To assess the analgesic efficacy and adverse effects of single-dose intravenous diclofenac, compared with placebo or an active comparator, for moderate to severe postoperative pain in adults.

SEARCH METHODS

We searched the following databases without language restrictions: the Cochrane Central Register of Controlled Trials (Cochrane Register of Studies Online), MEDLINE, and Embase on 22 May 2018. We checked clinical trials registers and reference lists of retrieved articles for additional studies.

SELECTION CRITERIA

We included randomized trials that compared a single postoperative dose of intravenous diclofenac with placebo or another active treatment, for treating acute postoperative pain in adults following any surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently considered trials for review inclusion, assessed risk of bias, and extracted data.Our primary outcome was the number of participants in each arm achieving at least 50% pain relief over a four- and six-hour period.Our secondary outcomes were time to, and number of participants using rescue medication; withdrawals due to lack of efficacy, AEs, and for any cause; and number of participants experiencing any AE, serious AEs (SAEs), and NSAID-related AEs. We performed a post hoc analysis of opioid-related AEs, to enable indirect comparisons with other analyses of postoperative analgesics.For subgroup analysis, we planned to analyze different doses and formulations of parenteral diclofenac separately.We assessed the overall quality of the evidence for each outcome using GRADE and created two 'Summary of findings' tables.

MAIN RESULTS

We included eight studies, involving 1756 participants undergoing various surgeries (dental, mixed minor, abdominal, and orthopedic), with 20 to 175 participants receiving intravenous diclofenac in each study. Mean study population ages ranged from 24.5 years to 54.5 years. Intravenous diclofenac doses varied among and within studies, ranging from 3.75 mg to 75 mg. Five studies assessed newer formulations of parenteral diclofenac that could be administered as an undiluted intravenous bolus. Most studies had an unclear risk of bias for several domains and a high risk of bias due to small sample size. The overall quality of evidence for each outcome was generally low for reasons including unclear risk of bias in studies, imprecision, and low event numbers.Primary outcomeThree studies (277 participants) produced a number needed to treat for an additional beneficial outcome (NNTB) for at least 50% of maximum pain relief versus placebo of 2.4 (95% confidence interval (CI) 1.9 to 3.1) over four hours (low-quality evidence). Four studies (436 participants) produced an NNTB of 3.8 versus placebo (95% CI 2.9 to 5.9) over six hours (low-quality evidence). No studies provided data for the comparison of intravenous diclofenac with another NSAID over four hours. At six hours there was no difference between intravenous diclofenac and another NSAID (low-quality evidence).Secondary outcomesFor secondary efficacy outcomes, intravenous diclofenac was generally superior to placebo and similar to other NSAIDs.For time to rescue medication, comparison of intravenous diclofenac versus placebo demonstrated a median of 226 minutes for diclofenac versus 80 minutes for placebo (5 studies, 542 participants, low-quality evidence). There were insufficient data for pooled analysis for comparisons of diclofenac with another NSAID (very low-quality evidence).For the number of participants using rescue medication, two studies (235 participants) compared diclofenac with placebo. The number needed to treat to prevent one additional harmful event (NNTp) (here, the need for rescue medication) compared with placebo was 3.0 (2.2 to 4.5, low-quality evidence). The comparison of diclofenac with another NSAID included only one study (98 participants). The NNTp was 4.5 (2.5 to 33) for ketorolac versus diclofenac (very low-quality evidence).The numbers of participants withdrawing were generally low and inconsistently reported (very low-quality evidence). Participant withdrawals were: 6% (8/140) diclofenac versus 5% (7/128) placebo, and 9% (8/87) diclofenac versus 7% (6/82) another NSAID for lack of efficacy; 2% (4/211) diclofenac versus 0% (0/198) placebo, and 3% (4/138) diclofenac versus 2% (2/129) another NSAID due to AEs; and 11% (21/191) diclofenac versus 17% (30/179) placebo, and 18% (21/118) diclofenac versus 15% (17/111) another NSAID for any cause.Overall adverse event rates were similar between intravenous diclofenac and placebo (71% in both groups, 2 studies, 296 participants) and between intravenous diclofenac and another NSAID (55% and 58%, respectively, 2 studies, 265 participants) (low-quality evidence for both comparisons). Serious and specific AEs were rare, preventing meta-analysis.There were sufficient data for a dose-effect analysis for our primary outcome for only one alternative dose, 18.75 mg. Analysis of the highest dose employed in each study demonstrated a relative benefit compared with placebo of 1.9 (1.4 to 2.4), whereas for the group receiving 18.75 mg, the relative benefit versus placebo was 1.6 (1.2 to 2.1, 2 studies). Compared to another NSAID, the high-dose analysis demonstrated a relative benefit of 0.9 (0.8 to 1.1), for the group receiving 18.75 mg, the relative benefit was 0.78 (0.65 to 0.93). For direct comparison of high dose versus 18.75 mg, the proportion of participants with at least 50% pain relief was 66% (90/137) for the high-dose arm versus 57% (77/135) in the low-dose arm. There were insufficient data for subgroup meta-analysis of different diclofenac formulations.

AUTHORS' CONCLUSIONS

The amount and quality of evidence for the use of intravenous diclofenac as a treatment for postoperative pain is low. The available evidence indicates that postoperative intravenous diclofenac administration offers good pain relief for the majority of patients, but further research may impact this estimate. Adverse events appear to occur at a similar rate to other NSAIDs. Insufficient information is available to assess whether intravenous diclofenac has a different rate of bleeding, renal dysfunction, or cardiovascular events versus other NSAIDs. There was insufficient information to evaluate the efficacy and safety of newer versus traditional formulations of intravenous diclofenac. There was a lack of studies in major and cardiovascular surgeries and in elderly populations, which may be at increased risk for adverse events.

Drug development in anaesthesia: industrial perspective

PURPOSE OF REVIEW

In this review, we summarize the new drugs in development in the anaesthesia field.

RECENT FINDINGS

There are some interesting approaches, including pro-drugs of propofol such as Aquavan (MGI Pharma, Bloomington, Minnesota, USA) and novel 'soft-drug' sedatives and hypnotics (e.g. CNS-7259X and TD-4756) as well as a novel approach to terminate the action of steroidal neuromuscular blockers (sugammadex). There is also significant activity in the field of novel analgesics. Particularly addressing the fields of sedatives, hypnotics and neuromuscular blockers, however, there is relatively little drug discovery activity currently. Part of the reason for this may be that the mechanisms of action of anaesthetics are not fully understood. This cannot be the whole story, however, since attractive new targets have recently been identified. For example, an agent with selective actions at the beta3-containing subunit of the gamma-amino butyric acid-A receptor is likely to have the hypnotic effects of propofol without the cardiac depressant side-effects.

SUMMARY

We consider the main reason for low activity is the perception in industry that there is little need for new drugs in anaesthesia because the needs are well addressed by existing agents. If this is not the case then anaesthesiologists need to be more effective in communicating their requirements.

The efficacy of preoperative versus postoperative rofecoxib for preventing acute postoperative dental pain: a prospective randomized crossover study using bilateral symmetrical oral surgery

BACKGROUND

Previous data have demonstrated that rofecoxib has good analgesic efficacy for acute postoperative dental pain. However, up to half of these patients require rescue analgesics within the first 24 hours. As the timing of analgesic interventions may be an important factor in pain control, the present study tested the hypothesis that rofecoxib administered preoperatively would improve the analgesic efficacy and reduce rescue analgesic requirements within the first 24 hours compared with postoperative administration.

METHODS

This was a double-blind, randomized, crossover study where 45 patients had each of their identical impacted mandibular third molars removed under local anesthesia on 2 separate occasions. Patients acted as their own control; one side was pretreated with rofecoxib 50 mg, 2 hours before surgery, followed by placebo 15 minutes after surgery, and the contralateral side was pretreated with placebo 2 hours before surgery and posttreated with rofecoxib 50 mg 15 minutes after surgery. The difference in postoperative pain between 2 sides was assessed by 4 primary end-points: pain intensity as measured by a 100-mm visual analogue scale hourly for 12 hours, time to rescue analgesic, postoperative analgesic consumption, and patient's global assessment.

RESULTS

Patients reported significantly lower pain scores (P = 0.04), longer time to rescue analgesic (P = 0.02), lesser postoperative analgesic consumption (P = 0.008), and better global assessment (P = 0.01) in the pretreated compared with the posttreated sides. There were significantly more patients in the pretreated group who did not required rescue analgesic within the first 24 hours (80% vs. 58%, P = 0.01), and the pain scores were extremely low in both groups during the 12 hours postoperative period (9.8 +/- 5.0 mm vs. 14.3 +/- 7.4 mm).

CONCLUSION

Rofecoxib is an excellent analgesic for preventing postoperative dental pain and when given 2 hours preoperatively rendered most patients relatively pain free, requiring no rescue analgesics on the first postoperative day.

Effect of diclofenac pretreatment on pain during propofol injection

In a randomized, double-blind, controlled trial, 120 ASA 1 or 2 patients were allocated to receive diclofenac or normal saline as pretreatment to assess their effect on incidence and severity of pain during propofol injection. Diclofenac in two different doses, i.e. 25 mg and 15 mg, was tried for this purpose. The overall incidence of pain did not significantly differ among the groups, but the incidence of moderate to severe pain following propofol injection was significantly less in patients who received diclofenac 25 mg (P = 0.0017) or 15 mg (P = 0.0363) than in those who received saline. However, the diclofenac itself was associated with mild pain in some patients.

Colon perforation with acute peritonitis after taking clindamycin and diclofenac following wisdom tooth removal

INTRODUCTION

Non-steroidal anti-inflammatory drugs have a high analgesic and anti-inflammatory effect and are widely taken for acute and chronic pain. Especially following long-term use, they may cause gastrointestinal side effects such as mucosal ulceration, perforation and strictures in the small and large bowel.

PATIENT

A 16-year-old female developed colonic perforation and purulent peritonitis after wisdom tooth removal and short-term intake of non-steroidal anti-inflammatory drugs.

DISCUSSION

Non-steroidal anti-inflammatory drugs may exert their deleterious effects on the lower gastrointestinal tract through both local and systemic actions. Systemic effects are caused by the inhibition of cyclooxygenase and reduction of protective prostaglandins. The local damage of the intestinal mucosa in the distal bowel segments seems to be caused by sustained release formulation with a high enterohepatic circulation. The latter may act time and again on the intestinal mucosa through metabolites secreted in the gallbladder. Concomitant intake of clindamycin may have favoured this acute complication.

CONCLUSION

Intestinal perforation after short-term intake of non-steroidal anti-inflammatory drugs is very rare. However, it is life-threatening and illustrates the need for careful prescribing at as low an effective dose and as short a time as possible, especially when combining different drugs. Paracetamol only has a weak effect on cyclooxygenase and continues to be a possible alternative for postoperative dental pain with a favourable benefit-risk ratio. It is the drug of choice for children, adolescents and patients with an increased risk of non-steroidal anti-inflammatory drug-induced gastro-enteropathy.

Comparison of the analgesic efficacy of rofecoxib and enteric-coated diclofenac sodium in the treatment of postoperative dental pain: a randomized, placebo-controlled clinical trial

BACKGROUND

Rofecoxib is a selective cyclooxygenase-2 inhibitor indicated for the treatment of acute pain, with similar analgesic efficacy to ibuprofen and naproxen sodium. Diclofenac sodium is the most commonly prescribed nonsteroidal anti-inflammatory drug worldwide; it is effective for the treatment of pain as well as the signs and symptoms associated with the painful conditions of osteoarthritis and rheumatoid arthritis.

OBJECTIVE

The aim of this study was to compare the analgesic efficacy and tolerability of a single dose of rofecoxib 50 mg, 3 doses of enteric-coated diclofenac sodium 50 mg, and placebo over 8-hour and 24-hour periods in patients with moderate to severe pain after oral surgery.

METHODS

In this double-blind, placebo- and active comparator-controlled, parallel-group study, patients experiencing moderate to severe pain after the surgical extraction of > or = 2 third molars were randomized to receive a single dose of rofecoxib 50 mg, 3 doses of enteric-coated diclofenac sodium 50 mg (50 mg given every 8 hours), or placebo. Patients rated pain intensity, pain relief, and global assessments at prespecified times throughout the 24-hour period after initial dosing. Overall analgesic efficacy was determined by total pain relief over 8 hours (TOPAR8) and 24 hours (TOPAR24) and patient global assessments at 8 and 24 hours. Onset of analgesic effect was determined by using the 2-stopwatch method for confirmed perceptible pain relief. Peak analgesic effect was the maximum pain relief attained during the first 8 hours. The duration of analgesic effect was determined by median time to rescue analgesia use.

RESULTS

A total of 305 patients were randomized to treatment: 121 received rofecoxib, 121 received diclofenac sodium, and 63 received placebo. The baseline demographics were similar among the groups. Overall, 61.3% experienced moderate pain and 38.7% experienced severe pain; 53.1% were female; and the mean age was 23.4 years. The overall analgesic efficacy, as assessed by TOPAR8, of a single dose of rofecoxib 50 mg was significantly greater than a single dose of enteric-coated diclofenac sodium 50 mg (20.5 vs 8.2) and placebo (20.5 vs 5.9). Patient global assessment at 8 hours was also significantly better for rofecoxib compared with enteric-coated diclofenac sodium and placebo. TOPAR24 was significantly greater for a single dose of rofecoxib 50 mg compared with 3 doses of enteric-coated diclofenac sodium 50 mg (64.1 vs 25.1) and placebo (64.1 vs 19.2). At 24 hours, the patient global assessment for rofecoxib was significantly better than that achieved with enteric-coated diclofenac sodium and placebo. The onset of analgesic effect was significantly more rapid for rofecoxib than for enteric-coated diclofenac sodium and placebo (median times: 31 minutes, >4 hours, and >4 hours, respectively). The peak analgesic effect was significantly greater for rofecoxib compared with enteric-coated diclofenac sodium (3.2 vs 1.5) and placebo (3.2 vs 1.1). The duration of analgesia was significantly longer for rofecoxib than enteric-coated diclofenac sodium (median times: >24 hours vs 1 hour and 37 minutes) and placebo (>24 hours vs 1 hour and 37 minutes). Enteric-coated diclofenac sodium was numerically greater than placebo for the key end points measuring overall efficacy (total pain relief and patient global assessment), but diclofenac sodium did not provide as much analgesic effect as expected for a drug effective for pain, osteoarthritis, and rheumatoid arthritis and did not differ significantly from placebo. Overall, both rofecoxib and enteric-coated diclofenac sodium were generally well tolerated, although the rofecoxib group had a significantly lower incidence of clinical and drug-related adverse events than the enteric-coated diclofenac sodium group.

CONCLUSIONS

A single 50-mg dose of rofecoxib provided greater overall analgesic efficacy over 8 hours, more rapid onset of analgesia, greater maximum analgesic effect, and longer duration of effect than a single 50-mg dose of enteric-coated diclofenac sodium in patients with moderate to severe pain associated with oral surgery. Compared with 3 doses of enteric-coated diclofenac sodium 50 mg (50 mg every 8 hours), a single dose of rofecoxib 50 mg provided greater overall analgesic efficacy over 24 hours.