Ketorolac and gastrointestinal ulceration

Parecoxib: a shift in pain management?

Parecoxib (Dynastat) is a parenteral cyclooxygenase-2 inhibitor available in Europe. Clinical trials have reported a benefit in reducing pain following oral, orthopedic, gynecologic and cardiac surgeries. The overall efficacy was dose-related and similar to ketorolac (Toradol). Several trials reported an opioid-sparing effect with parecoxib. No trials have reported significantly fewer opioid-related gastrointestinal side effects (e.g., nausea, vomiting, constipation and intestinal ileus) when opioids were administered with parecoxib versus placebo. Gastroduodenal ulcers, gastric ulcers and duodenal ulcers or erosions were less common with parecoxib than ketorolac. Parecoxib does not affect platelet aggregation, interfere with the antiplatelet affect of aspirin, affect prothrombin and partial thromboplastin time or platelet counts when administered with heparin.

COX-1, COX-2 and the topical effect in NSAID-induced enteropathy

The side effects of NSAIDs are equally evident in the stomach and the small bowel. The latter is increasingly seen as being clinically significant, contributing substantially to the iron-deficiency anaemia that is so common in patients with rheumatoid arthritis. Furthermore, NSAID-enteropathy may be associated with life-threatening events. The pathogenesis of NSAID-enteropathy is uncertain but inhibition of COX-1 is believed to be of pivotal importance. However there is increasing evidence that COX-2 inhibition and the topical effect may have a synergistic detrimental action. We examined the role of COX-1, COX-2 and the so called topical effect of acidic NSAIDs. We found that COX-1 or COX-2 inhibition and the topical effect alone do not damage the GI tract. Dual inhibition of COX-1 and COX-2 results in intestinal inflammation similar to that caused by Indomethacin. The topical effect may act synergistically in this damage. The conventional view that the mechanism of gastrointestinal damage is principally caused by COX-1 inhibition needs to be revised in view of recent studies using selective inhibitors of the COX enzymes and COX knockout animals.

Mucosal defense and repair. Role of prostaglandins in the stomach and duodenum

When considering the diseases of the stomach and duodenum, peptic ulcer disease has been the one of greatest clinical impact. Although there are several components that contribute mechanistically to ulcer disease, it is recognized that gastroduodenal mucosal prostaglandins play a central pathogenic role, especially in ulcers related to the use of NSAIDs. As a result of understanding the mechanisms of NSAID-induced ulceration, the crucial function that gastroduodenal mucosal prostaglandins have in mucosal defense and repair is appreciated. It now is held widely that mucosal prostaglandin deficiency increases susceptibility to ulcer formation and that exogenous administration of supplemental prostaglandins reduces ulcer risk. This article reviews the role that mucosal prostaglandins play in defense of the gastric and duodenal mucosa against injury and ulceration.

Effects of very low dose daily, long-term aspirin therapy on gastric, duodenal, and rectal prostaglandin levels and on mucosal injury in healthy humans

BACKGROUND & AIMS

The safety of low-dose daily aspirin therapy in the gastrointestinal tract is uncertain. Our objectives were to evaluate the long-term effects of very low daily aspirin doses in the gastrointestinal tract and effects on platelet-derived serum thromboxane levels in volunteers.

METHODS

Subjects were randomized to receive 10 mg (n = 8), 81 mg (n = 11), or 325 mg (n = 10) aspirin daily for 3 months. Before administration of aspirin, all subjects underwent gastroduodenoscopy, and most underwent proctoscopy for assessment of mucosal injury and prostaglandin content. After 1.5 and 3 months, subjects again underwent gastroduodenoscopy and, at 3 months, another proctoscopy.

RESULTS

Each aspirin dose (even 10 mg) significantly reduced gastric mucosal prostaglandin levels, to approximately 40% of the baseline value. All three doses also induced significant gastric injury, and 325 mg caused duodenal injury. Three subjects developed gastric ulcers, 1 while taking 10 mg/day of aspirin. Furthermore, aspirin at 81 mg/day and 325 mg/day (but not 10 mg/day) significantly reduced duodenal mucosal prostaglandin levels to approximately 40% of the baseline value. Only 325 mg of aspirin per day significantly reduced rectal mucosal prostaglandin levels to approximately 60% of the baseline value. Serum thromboxane levels were inhibited 62%, 90%, and 98% with 10, 81, and 325 mg of aspirin.

CONCLUSIONS

The findings explain aspirin's predominant gastric toxicity and question the safety of even 10 mg of aspirin daily.

Ketorolac. A reappraisal of its pharmacodynamic and pharmacokinetic properties and therapeutic use in pain management

Ketorolac is a nonsteroidal anti-inflammatory drug (NSAID) with strong analgesic activity. The analgesic efficacy of ketorolac has been extensively evaluated in the postoperative setting, in both hospital inpatients and outpatients, and in patients with various other acute pain states. After major abdominal, orthopaedic or gynaecological surgery or ambulatory laparoscopic or gynaecological procedures, ketorolac provides relief from mild to severe pain in the majority of patients and has similar analgesic efficacy to that of standard dosages of morphine and pethidine (meperidine) as well as less frequently used opioids and other NSAIDs. The analgesic effect of ketorolac may be slightly delayed but often persists for longer than that of opioids. Combined therapy with ketorolac and an opioid results in a 25 to 50% reduction in opioid requirements, and in some patients this is accompanied by a concomitant decrease in opioid-induced adverse events, more rapid return to normal gastrointestinal function and shorter stay in hospital. In children undergoing myringotomy, hernia repair, tonsillectomy, or other surgery associated with mild to moderate pain, ketorolac provides comparable analgesia to morphine, pethidine or paracetamol (acetaminophen). In the emergency department, ketorolac attenuates moderate to severe pain in patients with renal colic, migraine headache, musculoskeletal pain or sickle cell crisis and is usually as effective as frequently used opioids, such as morphine and pethidine, and other NSAIDs and analgesics. Subcutaneous administration of ketorolac reduces pain in patients with cancer and seems particularly beneficial in pain resulting from bone metastases. The acquisition cost of ketorolac is greater than that of morphine or pethidine; however, in a small number of studies, the higher cost of ketorolac was offset when treatment with ketorolac resulted in a reduced hospital stay compared with alternative opioid therapy. The tolerability profile of ketorolac parallels that of other NSAIDs; most clinically important adverse events affect the gastrointestinal tract and/or renal or haematological function. The incidence of serious or fatal adverse events reported with ketorolac has decreased since revision of dosage guidelines. Results from a large retrospective postmarketing surveillance study in more than 20,000 patients demonstrated that the overall risk of gastrointestinal or operative site bleeding related to parenteral ketorolac therapy was only slightly higher than with opioids. However, the risk increased markedly when high dosages were used for more than 5 days, especially in the elderly. Acute renal failure may occur after treatment with ketorolac but is usually reversible on drug discontinuation. In common with other NSAIDs, ketorolac has also been implicated in allergic or hypersensitivity reactions. In summary, ketorolac is a strong analgesic with a tolerability profile which resembles that of other NSAIDs. When used in accordance with current dosage guidelines, this drug provides a useful alternative, or adjuvant, to opioids in patients with moderate to severe pain.

Gastrointestinal complications associated with intramuscular ketorolac tromethamine therapy in the elderly

OBJECTIVE

To report 3 cases of gastrointestinal (GI) complications associated with the use of intramuscular ketorolac tromethamine therapy in elderly patients.

CASE SUMMARIES

In case 1, an 88-year-old woman was taken to surgery for the management of an acute abdomen and repair of a 2+ cm perforated prepyloric gastric ulcer. The patient had received a total 16 doses of ketorolac 30 mg im. The patient died after surgery from complications associated with bacterial and candidal sepsis, as well as acute renal failure. In case 2, an 80-year-old woman with no known history of GI problems developed a prepyloric gastric ulcer, which perforated and penetrated into the pancreas after the patient received 13 doses of ketorolac 30 mg im. The patient died from complications associated with candidal sepsis, peritonitis, and cardiopulmonary collapse. In case 3, an 85-year-old man with a history of a gastric ulcer developed GI bleeding after receiving a total of 9 doses of ketorolac 30 mg im. The bleeding was stabilized and the patient was discharged 12 days later in stable condition.

DISCUSSION

Ketorolac tromethamine is a nonsteroidal anti-inflammatory drug with potent analgesic properties. We report 3 cases of GI complications associated with intramuscular ketorolac therapy in the elderly. A temporal relationship was established with the development of gastric ulceration in 2 patients and the recurrence of a gastric ulcer in the third patient.

CONCLUSIONS

We recommend that the manufacturer's guidelines be followed when ketorolac is used in elderly patients, and the drug should not be used in patients with a history of gastric ulcer disease. The use of misoprostol may be warranted as prophylactic therapy in high-risk patients who are receiving ketorolac.

Clinical experience with ketorolac in children

OBJECTIVE

To describe the use of parenteral ketorolac in a large population of children, focusing on dosing patterns, efficacy, and safety.

DESIGN

Observational, prospective study conducted over a four-month period.

SETTING

A 122-bed children's medical center located within an academic medical center hospital.

PARTICIPANTS

Children receiving ketorolac during their hospitalization.

MAIN OUTCOME PARAMETERS

Indications for treatment, dose, dosing interval, use of a loading dose, length of therapy, efficacy (subjective response and use of concomitant therapy), and adverse effects (bleeding, gastrointestinal ulceration or vomiting, and renal dysfunction).

RESULTS

Of 112 children evaluated, 110 received ketorolac for analgesia, and 2 were given ketorolac as an antipyretic. The children ranged in age from 6 months to 19 years. Doses of 0.5 mg/kg q6h were used for most children (range 0.17-1.0). The average length of therapy was 3.4 days (range 1-12). The most frequent reason for discontinuing ketorolac therapy was a change to oral therapy. Therapy was discontinued because of a lack of efficacy in only 2 children. Adverse reactions were unusual, with only 2 patients having bleeding potentially associated with ketorolac use.

CONCLUSIONS

Ketorolac appears to be a safe and effective therapy for children when given in appropriate doses for a limited duration.