The analgesic efficacy of ketorolac for acute pain

Comparative Effectiveness of Ketorolac Dosing Strategies for Emergency Department Patients With Acute Pain

STUDY OBJECTIVES

Ketorolac is a commonly used nonopioid parenteral analgesic for treating emergency department (ED) patients with acute pain. Our systematic review aims to summarize the available evidence by comparing the efficacy and safety of differing ketorolac dosing strategies for acute pain relief in the ED.

METHODS

The review was registered on PROSPERO (CRD42022310062). We searched MEDLINE, PubMed, EMBASE, and unpublished sources from inception through December 9, 2022. We included randomized control trials of patients presenting with acute pain to the ED, comparing ketorolac doses less than 30 mg (low dose) to ketorolac doses more than or equal to 30 mg (high dose) for the outcomes of pain scores after treatment need for rescue analgesia, and incidence of adverse events. We excluded patients in non-ED settings, including postoperative settings. We extracted data independently and in duplicate and pooled them using a random-effects model. We assessed the risk of bias using the Cochrane Risk of Bias 2 tool and the overall certainty of the evidence for each outcome using the Grading Recommendations Assessment, Development, and Evaluation approach.

RESULTS

This review included 5 randomized controlled trials (n=627 patients). Low-dose parenteral ketorolac (15 to 20 mg), as compared to high-dose ketorolac (≥30 mg), probably has no effect on pain scores (mean difference 0.05 mm lower on 100 mm visual analog scale, 95% confidence interval [CI] -4.91 mm to +5.01 mm; moderate certainty). Further, low-dose ketorolac at 10 mg may have no effect on pain scores compared to high-dose ketorolac (mean difference 1.58 mm lower on 100 mm visual analog scale, 95% CI -8.86 mm to +5.71 mm; low certainty). Low-dose ketorolac may increase the need for rescue analgesia (risk ratio 1.27, 95% CI 0.86 to 1.87; low certainty) and may have no difference on rates of adverse events (risk ratio 0.84, 95% CI 0.54 to 1.33; low certainty).

CONCLUSION

In adult ED patients with acute pain, parenteral ketorolac given at doses of 10 mg to 20 mg is probably as effective in relieving pain as doses of 30 mg or higher. Low-dose ketorolac may have no effect on adverse events, but these patients may require more rescue analgesia. This evidence is limited by imprecision and is not generalizable to children or those at higher risk of adverse events.

The Additive Antinociceptive Effect of Resveratrol and Ketorolac in the Formalin Test in Mice

Pain represents one of the leading causes of suffering and disability worldwide. Currently available drugs cannot treat all types of pain and may have adverse effects. Hence, the use of pharmacological combinations is an alternative treatment strategy. Therefore, this study aimed to evaluate the combination of resveratrol and ketorolac through isobolographic analysis. CD1 mice were used to study the antinociceptive effect of this combination using the formalin test and the study was divided into two phases. In the first phase, four individual doses of each drug were evaluated, totaling eight testing groups. From these data, the median effective doses (ED50) of each drug were calculated. In the second phase, four testing groups were used to evaluate the combination of sub-doses of both drugs and obtain the experimental ED50. To evaluate gastric damage, five groups were employed, including indomethacin, vehicle, resveratrol, ketorolac, and combined resveratrol and ketorolac groups. Stomach samples from the mice were taken after 5 h of treatment, and the area of the ulcers was determined. Resveratrol plus ketorolac elicited a reduction in nociceptive behavior during both phases of the formalin test, and isobologram analysis revealed that the theoretical and experimental ED50 values of resveratrol and ketorolac did not differ significantly, implying an additive interaction between the drugs. Additionally, the drug combination did not generate gastric ulcers, thus enhancing the desired effects without increasing the adverse effects. Consequently, these findings substantiate the efficacy of the resveratrol and ketorolac combination in the formalin test, thereby highlighting its potential as a viable alternative for alleviating pain.

Implementation of Multimodal Pain Protocol Associated With Opioid Use Reduction in Trauma Patients

INTRODUCTION

Many trauma centers have adopted multimodal pain protocols (MMPPs) to provide safe and effective pain control. The objective was to evaluate the association of a protocol on opioid use in trauma patients and patient-reported pain scores.

METHODS

This was a retrospective review of adult trauma patients admitted from 7/1-9/30/2018 to 7/1-9/30/2019 at an urban academic level 1 trauma center. The MMPP consisted of scheduled nonopioid medications implemented on July 1, 2019. Patients were stratified by level of care upon admission, intensive care unit (ICU) or floor, and by injury severity score (ISS) (ISS < 16 or ISS ≥ 16). Pain scores, opioid, and nonopioid analgesic medication use were compared for the hospital stay or first 30 d.

RESULTS

Seven hundred ninety eight patients were included with a mean age of 54 ± 22 y and 511 (64.0%) were men. Demographic and clinical characteristics between those in the pre-MMP (n = 404) and post-MMPP (n = 394) groups were not different. The average pain scores were not different between the two groups (3.7 versus 3.8, P = 0.44), but patients in the post-MMPP group received 36% less morphine milliequivalents (109.6 versus 70; P < 0.0001). The MMPP had the largest effect on patients admitted to the ICU regardless of injury severity. ICU patients with ISS ≥ 16 had the greatest reduction in morphine milliequivalents (174.6 versus 84.4; P < 0.0001). The use of nonopioid analgesics was significantly increased in all groups.

CONCLUSIONS

A MMPP is associated with a reduction of opioids and increase in nonopioid analgesics with no difference in patient-reported pain scores.

Periarticular Injection of Ketorolac Augmenting Intravenous Administration of Ketorolac for Postoperative Pain Control: A Randomized Controlled Trial in Simultaneous Bilateral Total Knee Arthroplasty

Adequate postoperative pain control with minimal side effects is necessary for patients undergoing total knee arthroplasty (TKA). Ketorolac is a frequently used nonsteroidal anti-inflammatory drug due to its excellent disposition in all administration routes; however, it possesses an "analgesic ceiling," which means that higher doses of the drug have no additional analgesic effect. Alternatively, increasing the local concentration of ketorolac via periarticular injection may provide additional pain relief to parenteral administration of ketorolac, but evidence demonstrating the benefits and safety of this approach is limited. Therefore, this study assesses whether local ketorolac injection could yield additional pain reduction to intravenous administration of ketorolac. A total of 54 patients who underwent simultaneous bilateral TKA were enrolled. Randomization was performed to determine whether 50 mg of bupivacaine plus 30 mg of ketorolac (ketorolac group), or only 50 mg bupivacaine (bupivacaine group) would be periarticularly injected into the first knee operated on (more painful), and then the contralateral knee would receive another mixture. Ketorolac (30 mg) was intravenously given every 8 hours for the first 48 hours. Visual analog scales (VASs) were used to assess pain, knee recovery function, and patients' preferred knee. Postoperative VAS pain scores in the ketorolac group were lower than those in the bupivacaine group 6 to 96 hours postoperatively and reached statistical significance 12 (4.25 ± 2.38 vs. 5.06 ± 2.48, respectively; p = 0.04) and 24 hours (4.22 ± 1.94 vs. 5.30 ± 2.12, respectively; p < 0.01) postoperatively. The ketorolac group had higher degrees of knee flexion and straight leg raise. No patient experienced adverse effects of ketorolac. On the day of discharge, 61.11% of the patients favored the knee that received local ketorolac injection (p < 0.01). Adjunct local ketorolac injection to systemic administration is well tolerated and may improve its analgesic effect as determined by the patients' perception.

Comparing two doses of intramuscular ketorolac for treatment of acute musculoskeletal pain in a military emergency department

STUDY OBJECTIVE

The goal of the study was to assess a low-dose versus a high-dose of intramuscular (IM) ketorolac for non-inferiority in adults with acute MSK pain in an emergency department (ED).

METHODS

This was a single-blinded, randomized controlled, non-inferiority trial of adults presenting to an ED with a chief complaint of acute MSK pain. Patients were randomized to either a 15 mg or a 60 mg IM ketorolac dose. The primary outcome was the mean difference of change in pain from baseline to 60-min between the two groups as reported on a 100-mm (mm) visual analog scale (VAS). Secondary outcomes included the mean difference of change in VAS scores at 30-min and the incidence of reported adverse effects associated with the administration of ketorolac.

RESULTS

One hundred ten patients were randomized with 55 in each group. The mean difference in pain between groups at 60-min (0.2 mm [95% CI -8.5-8.7]; p = .98) and 30 min (-1.7 mm [95% CI -8.5-5.1; p = .63) was less than the predetermined non-inferiority margin of 13 mm. There were no major adverse effects reported. Minor adverse effects were more frequent in the 60 mg group (n = 9; 16.4% vs. n = 1; 1.8%; p = .016) with burning at the injection site being the most commonly reported.

CONCLUSIONS

A 15 mg dose of IM ketorolac was found to be non-inferior to a 60 mg dose for acute MSK pain in adults presenting to the ED. Discontinuing the practice of ordering 60 mg doses of IM ketorolac in place of a lower dose for acute MSK pain should be considered.

Ketorolac plus Lidocaine vs Lidocaine for pain relief following core needle soft tissue biopsy: A CONSORT-compliant double-blind randomized controlled study

BACKGROUNDS

The main objective of this study was to compare the pain control efficacy of local administration of Lidocaine with or without the nonsteroidal anti-inflammatory drug, Ketorolac, and local conventional Lidocaine injection in core needle biopsy of the musculoskeletal tumor.

METHODS

The current study was a randomized, double-blind controlled clinical trial that included 128 patients with suspected musculoskeletal tumors. Patients were randomly assigned to either the Ketorolac plus Lidocaine (n = 64) or Lidocaine group (n = 64). The Ketorolac - Lidocaine combination syringe contained 30 mg Ketorolac and 2% Lidocaine - adrenaline dosage, and the Lidocaine syringe contained 2% Lidocaine - adrenaline dosage. The level of pain after core needle biopsy was evaluated for each patient at 1, 6, 12, 24, 48, and >48 hours by a Visual Analog Scale (VAS). The mean VAS changes over time were compared between the Ketorolac plus Lidocaine and Lidocaine groups using a linear mixed model.

RESULTS

baseline information including mean age of patients in Lidocaine group (51.5 ± 19.4 years) and in Lidocaine - Ketorolac combination group (50.1 ± 18 years), diagnosis (malignant, benign, metastatic, infection), tumor location (upper and lower extremities, back), VAS score 1-hour post-operation (mild and moderate pain) were noted. The VAS score ratings were significantly lower in Lidocaine - Ketorolac combination group when compared to the Lidocaine group during the 1 to 24 hours post-operation time period.

CONCLUSION

Patients receiving Lidocaine - Ketorolac combination dosage had significantly lower VAS scores, and these results confirm that local injection of Lidocaine - Ketorolac combination had a superior pain-controlling effect during the first 24 hours after the biopsy procedure in comparison to Lidocaine injection alone, as measured by VAS score scale.

Low-molecular synthetic peptides with non-narcotic type of analgesia: comparative study and mechanism of analgesic activity

The group of synthetic low-molecular peptides exhibiting profound analgesic activity was developed by modifying the salmon calcitonin molecule fragment sCT_16-21, which retains the previously reported analgesic activity of the full-sized molecule. The mechanism of analgesic action of these synthetic oligopeptides has been investigated and their analgesic effect was compared with analgesic activity of ketorolac tromethamine, one of the strongest non-steroidal anti-inflammatory drug painkiller. It was demonstrated that the analgesic effect of the developed synthetic oligopeptides was associated with the specific binding of the clathrin heavy chain. It is postulated that inhibition of clathrin-mediated endocytosis of pain receptors in the postsynaptic vesicular cycle causes is more efficient analgesia than inhibition of those receptors on plasma membranes that may allow to replace opioid and non-steroidal anti-inflammatory drug’s analgesics with a much less toxic low-molecular synthetic peptides with non-narcotic type of analgesia.

Patterns of Ketorolac dosing by emergency physicians

BACKGROUND

Ketorolac tromethamine is a non-steroidal anti-inflammatory drug (NSAIDs) that is widely used in the emergency department (ED) for the treatment of moderate-to-severe pain. Ketorolac, like other NSAIDs, exhibits an analgesic ceiling effect and previous research suggests that 10 mg is possibly the ceiling dose. Do the patterns of ketorolac dosing by emergency physicians follow its analgesic ceiling dose?

METHODS

This was a single center retrospective, descriptive study to characterize patterns of ketorolac administration in ED patients. Data for all patients who received ketorolac during the ten year study period from January 1, 2003 to January 1, 2013 were collected from the electronic medical record of an urban community ED with an annual volume of 116 935 patients.

RESULTS

There were 49 605 ketorolac administrations during the study period; 38 687 (78%) were given intravenously, 9 916 (20%) intramuscularly, and 1 002 (2%) orally. Through the intravenous route, 5 288 (13.7%) were 15 mg, 32 715 (84.6%) were 30 mg, 15 (0.03%) were 60 mg, and 669 (1.7%) were other varying doses. Through the intramuscular route, 102 (1.0%) were 15 mg, 4 916 (49.6%) were 30 mg, 4 553 (45.9%) were 60 mg, and 345 (3.5%) were other varying doses. The most common diagnoses at discharge were renal colic (21%), low back pain (17%) and abdominal pain (11%).

CONCLUSION

The data show that ketorolac was prescribed above its ceiling dose of 10 mg in 97% of patients who received intravenous doses and in 96% of patients receiving intramuscular doses.

Advanced Concepts and Controversies in Emergency Department Pain Management

Pain is the most common complaint for which patients come to the emergency department (ED). Emergency physicians are responsible for pain relief in a timely, efficient, and safe manner in the ED. The improvement in our understanding of the neurobiology of pain has balanced the utilization of nonopioid and opioid analgesia, and simultaneously has led to more rational and safer opioid prescribing practices. This article reviews advances in pain management in the ED for patients with acute and chronic pain as well as describes several newer strategies and controversies.

Intravenous lidocaine for the emergency department treatment of acute radicular low back pain, a randomized controlled trial

BACKGROUND

Acute radicular back pain is a frequent complaint of patients presenting to the Emergency Department.

STUDY OBJECTIVE

Determine the efficacy of intravenous lidocaine when compared to ketorolac for the treatment of acute radicular low back pain.

METHODS

Randomized double-blind study of 41 patients aged 18-55 years presenting with acute radicular low back pain. Patients were randomized to receive either 100 mg lidocaine or 30 mg ketorolac intravenously over 2 min. A 100-mm visual analog scale (VAS) was used to assess pain at Time 0 (baseline), and 20, 40, and 60 minutes. Changes in [median] VAS scores were compared over time (within groups) by the signed-rank test and between groups by the rank-sum test. A 5-point Pain Relief Scale (PRS) was administered at the conclusion of the study (60 min) and again at 1 week by telephone follow-up; [median] scores were compared between groups by rank-sum.

RESULTS

Forty-four patients were recruited; 41 completed the study (21 lidocaine, 20 ketorolac). Initial VAS scores were not significantly different between the lidocaine and ketorolac groups (83; 95% confidence interval [CI] 74-98 vs. 79; 95% CI 64-94; p = 0.278). Median VAS scores from baseline to 60 min significantly declined in both groups (lidocaine [8; 95% CI 0-23; p = 0.003]; ketorolac [14; 95% CI 0-28; p = 0.007]), with no significant difference in the degree of reduction between groups (p = 0.835). Rescue medication was required by 67% receiving lidocaine, compared to 50% receiving ketorolac. No significant change in PRS between groups was found at the conclusion or at the follow-up.

CONCLUSION

Intravenous lidocaine failed to clinically alleviate the pain associated with acute radicular low back pain.

Intravenous paracetamol: a review of efficacy and safety in therapeutic use

Paracetamol is well established as a leading nonprescription antipyretic analgesic drug and is available in oral, rectal or intravenous forms. However, except for oral paracetamol, there is a marked discrepancy between the extent to which paracetamol is used and the available evidence for an analgesic effect in postoperative pain. This review mainly focuses on intravenous paracetamol. Its efficacy and safety are analyzed, as well as its use in therapeutics, alone or in combination. The morphine-sparing, additive and antihyperalgesia effects of intravenous paracetamol are also reviewed. The analyses are divided into several sections, comparing the efficacy of intravenous paracetamol with placebo, other forms of paracetamol or analgesic agents and analyzing its efficacy in multimodal therapy combined with NSAIDs or a morphinic agent.

Basic pharmacology and advances in emergency medicine

To provide optimal pain control for their patients, emergency physicians should have an in-depth understanding of analgesic drugs and how to use and combine them effectively. The purpose of this article is to describe the pharmacology and use of analgesic agents that are most useful in the management of acute pain in the emergency department.

Appropriately Timed Analgesics Control Pain Due to Chest Tube Removal

• Background Pain during chest tube removal can be moderately to severely intense and distressful to patients. Little evidence-based research has guided clinicians in attempts to alleviate such pain.

• Objective To test pharmacological and nonpharmacological interventions to alleviate pain during chest tube removal in cardiac surgery patients.

• Methods Four interventions were tested in 74 patients in a randomized, double-blind study: (1) 4 mg intravenous morphine and procedural information; (2) 30 mg intravenous ketorolac and procedural information; (3) 4 mg intravenous morphine plus procedural and sensory information; and (4) 30 mg intravenous ketorolac plus procedural and sensory information. Analgesics were administered to correspond to peak effect, and scripted information was provided. Pain intensity and pain distress were measured before analgesic administration, immediately after chest tube removal, and 20 minutes later. Pain quality was measured immediately after chest tube removal. Level of sedation was measured before and 20 minutes after chest tube removal. Repeated-measures analyses of variance were used to test differences among groups over time.

• Results Pain intensity, pain distress, and sedation levels did not differ significantly among groups. However, procedural pain intensity (mean 3.26, SD 3.00) and pain distress (mean 2.98, SD 3.18) scores for all were low. Patients remained alert, regardless of which analgesic was administered.

• Conclusions If used correctly, either an opioid (morphine) or a nonsteroidal anti-inflammatory (ketorolac) can substantially reduce pain during chest tube removal without causing adverse sedative effects. Thus, clinicians may choose among several safe and effective analgesic interventions during chest tube removal.

Postoperative pain management in obstetric anesthesia–new challenges and solutions

The current understanding of pain processing mechanisms, the different pharmacologic drugs, and other nonpharmacologic means that can be used to manage postobstetric operation pain are reviewed.

Analysis of the analgesic interactions between ketorolac and tramadol during arthritic nociception in rat

The potential advantage of using combination therapy is that analgesia can be maximized while minimizing the incidence of adverse effects. In order to assess a possible synergistic antinociceptive interactions, the antinociceptive effects of ketorolac tromethamine, p.o., a nonsteroidal anti-inflammatory drug (NSAID), and tramadol hydrochloride, p.o., an atypical opioid analgesic, administered either separately or in combination, were determined using a rat model of arthritic pain. The data were interpreted using the surface of synergistic interaction (SSI) analysis and an isobolographic analysis to establish the nature of the interaction. The surface of synergistic interaction was calculated from the total antinociceptive effect produced by the combination after subtraction of the antinociceptive effect produced by each individual drug. Female rats received orally ketorolac alone (0.18, 0.32, 0.56, 1.0, 1.78, 3.16, and 5.62 mg/kg), tramadol alone (3.16, 5.62, 10.0, 17.78, 31.62, 56.23, and 100.0 mg/kg), or 24 different combinations of ketorolac plus tramadol. Ten combinations exhibited various degrees of potentiation of antinociceptive effects (17.78 mg/kg tramadol with either 0.18, 0.32, or 0.56 mg/kg ketorolac; 10.0 mg/kg tramadol with either 0.18, 0.32, 0.56, or 1.8 mg/kg ketorolac; 5.6 mg/kg tramadol with either 0.32 or 0.56 mg/kg ketorolac; and 3.16 mg/kg tramadol with 0.32 mg/kg ketorolac), whereas the other 14 combinations showed additive antinociceptive effects. Three combinations of ketorolac+tramadol (1.0+17.78, 1.78+10, and 1.78+17.78, mg/kg respectively) produced the maximum antinociceptive effects, and two combinations (0.32+10.0 and 0.56+10.0 mg/kg, respectively) presented effects of high potentiation (P<0.001). This combination caused gastric injuries less severe than those observed with indomethacin. The synergistic antinociceptive effects of ketorolac and tramadol were important and suggest that combinations with these drugs may have clinical utility in pain therapy.

Effect of celecoxib and dexamethasone on postoperative pain after lumbar disc surgery

OBJECTIVE

This study was designed to assess the efficacy of perioperative administration of celecoxib (Celebrex; Pharmacia GmbH, Erlangen, Germany) in reducing pain and opioid requirements after single-level lumbar microdiscectomy.

METHODS

We studied 34 patients (mean age, 44.26 yr; standard deviation [SD], 13.09 yr) allocated randomly to receive celecoxib 200 mg twice a day for 72 hours starting on the evening before surgery or placebo capsules in a double-blind study. Fourteen patients received 20 to 80 mg dexamethasone intravenously during surgery (mean, 40 mg; SD, 19.22 mg) because of visible signs of compression of the affected nerve root. After lumbar disc surgery, patients were monitored for visual analog scores for pain at rest and on movement, patient-controlled analgesia (PCA) piritramide requirements, and von Frey thresholds in the wound area.

RESULTS

Pain scores decreased and wound von Frey thresholds increased continuously until discharge, with no intergroup differences. Mean 24-hour PCA piritramide requirements were 22.63 mg (SD, 23.72 mg) and 26.14 mg (SD, 22.57 mg) in the celecoxib and placebo groups, respectively (P = not significant). However, patients with intraoperative dexamethasone (n = 14) required only 10.29 mg (SD, 8.55 mg) 24-hour PCA piritramide, in contrast to the 34.25 mg (SD, 24.69 mg) needed in those who did not receive intraoperative dexamethasone (P = 0.001). In addition, 24 hours after the operation, pain scores on movement were significantly lower in the dexamethasone subgroup (P = 0.003).

CONCLUSION

Celecoxib has no effect on postoperative pain scores and PCA piritramide requirements. The intraoperative use of 20 to 80 mg dexamethasone is able to significantly decrease postoperative piritramide consumption and pain scores on the first day after surgery.

Ketorolac versus acetaminophen-codeine in the emergency department treatment of acute low back pain

Acute low back pain is a common problem in the emergency department (ED). Effective management of acute pain enhances early rehabilitation and recovery. Given the importance of inflammatory mediators in pain generation and the adverse effects associated with opioids, it is logical to expect that a non-opioid agent with antiinflammatory and analgesic properties would provide excellent analgesia with fewer adverse effects. This double-blind, randomized, multicenter clinical trial, performed in six university and community hospital EDs, compares the analgesic efficacy and adverse effects of ketorolac to those of acetaminophen-codeine in ED patients with acute musculoskeletal low back pain. Our hypothesis was that ketorolac would provide superior analgesia with fewer adverse effects. One hundred twenty-three patients with acute low back pain were randomized to receive ketorolac (KET, N = 63) or acetaminophen-codeine (ACOD, N = 60). Most (79%) were males, and the mean age was 34.5 years. After baseline clinical assessment, patients were treated with ketorolac (10 mg every 4 to 6 h as needed, up to four daily doses) or acetaminophen-codeine (600 mg-60 mg, respectively, every 4 to 6 h as needed, up to six daily doses) and followed for one week. Pain intensity was assessed on visual analogue and categorical scales. Functional capacity, overall pain relief, and overall medication rating were assessed on categorical scales. Adverse events were documented. Primary outcomes included: 1) Pain intensity differences, based on visual analogue scores, for the 0 to 6 h treatment phase. 2) Incidence of adverse events. Secondary outcomes included analgesic efficacy, functional capacity, and overall subjective drug evaluation at one week. Both drugs provided substantial pain relief, with maximal effect 2.2 h after oral dosing. There were no significant differences in analgesic efficacy, functional capacity, or overall pain relief between the two groups. Sixteen patients (10 KET vs. 6 ACOD, NS) withdrew prematurely because of drug inefficacy. Patients in the ACOD group reported significantly more adverse drug events and serious adverse drug events. Seven patients--all in the ACOD group--withdrew from the study because of adverse drug events. Based on comparable efficacy and a superior adverse event profile, ketorolac was preferable to acetaminophen with codeine for the treatment of acute low back pain in the ED.