A double-blind study of prophylactic effect of misoprostol on lesions of gastric and duodenal mucosa induced by oral administration of tolmetin in healthy subjects

Association between adherence to evidence-based guidelines for the prescription of non-steroidal anti-inflammatory drugs and the incidence of gastric mucosal lesions in Japanese patients

OBJECTIVE

Recently, guidelines for the treatment and prevention of ulcers induced by non-steroidal anti-inflammatory drugs (NSAIDs) were established. This study investigated the association between the current adherence to the guidelines and the incidence of gastric mucosal lesions caused by NSAIDs.

METHODS

This study included 254 NSAIDs users (128 regular and 126 on-demand users) who had undergone upper gastrointestinal endoscopy. The patients were characterized as high risk based on the following: age 65 years or older, history of peptic ulcers, concurrent use of corticosteroids or anticoagulants, and high-dose NSAIDs use. Adherence was defined as the prescription of NSAIDs with proton pump inhibitors, prostaglandin analogues, or high-dose histamine 2 receptor antagonists in high-risk NSAIDs user. The severity of gastric mucosal lesions was evaluated using the modified LANZA score (MLS).

RESULTS

Seventy-nine (61.7%) of the regular NSAIDs users and 65 (51.6%) of the on-demand NSAIDs users met our definition of high-risk patients. Adherence in the regular NSAIDs users and on-demand NSAIDs users was 25 (31.7%) and 16 (24.6%), respectively. The incidence of gastric mucosal lesions (MLS ≧ 1) was significantly higher in the nonadherence group than in the adherence group for both regular NSAIDs users (59.3 vs. 28.0%, P = 0.01) and on-demand NSAIDs users (63.3 vs. 25.0%, P = 0.01). Gastric ulcers in the regular NSAIDs users were more frequently observed in the nonadherence group than in the adherence group (29.6 vs. 4.0%, P < 0.01).

CONCLUSION

Nonadherence was associated with a high prevalence of NSAIDs-induced gastric mucosal lesions.

Efficacy and safety of rabeprazole in non-steroidal anti-inflammatory drug-induced ulcer in Japan

AIM: To investigate the efficacy and safety of rabeprazole under continuous non-steroidal anti-inflammatory drug (NSAID) administration for NSAID-induced ulcer in Japan.

METHODS: Subjects comprised patients undergoing NSAID treatment in whom upper gastrointestinal endoscopy revealed an ulcerous lesion (open ulcer) with diameter ≥ 3 mm, who required continuous NSAID treatment. Endoscopies were performed at the start of treatment, during the treatment period, and at the conclusion (or discontinuation) of treatment. Findings were evaluated as size (maximum diameter) and stage based on the Sakita-Miwa classification. An ulcer was regarded as cured when the “white coating” was seen to have disappeared under endoscopy. As criteria for evaluating safety, all medically untoward symptoms and signs (adverse events, laboratory abnormalities, accidental symptoms, etc.) occurring after the start of rabeprazole treatment were handled as adverse events.

RESULTS: Endoscopic cure rate in 38 patients in the efficacy analysis (endoscopic evaluation) was 71.1% (27/38). Among those 38 patients, 35 had gastric ulcer with a cure rate of 71.4% (25/35), and 3 had duodenal ulcer with a cure rate of 66.7% (2/3). Three adverse drug reactions were reported from 64 patients in the safety analysis (interstitial pneumonia, low white blood cell count and pruritus); thus, the incidence rate for adverse drug reactions was 4.7% (3/64).

CONCLUSION: The treatment efficacy of rabeprazole for NSAID-induced ulcer under continuous NSAID administration was confirmed.

Guidelines for prevention of NSAID-related ulcer complications

Guidelines for clinical practice are intended to indicate preferred approaches to medical problems as established by scientifically valid research. Double-blind, placebo-controlled studies are preferable, but compassionate use reports and expert review articles are used in a thorough review of the literature conducted through Medline with the National Library of Medicine. Only when data that will not withstand objective scrutiny are available is a recommendation identified as a consensus of experts. Guidelines are applicable to all physicians who address the subject, without regard to specialty training or interests, and are intended to indicate the preferable, but not necessarily the only, acceptable approach to a specific problem. Guidelines are intended to be flexible and must be distinguished from standards of care, which are inflexible and rarely violated. Given the wide range of specifics in any health-care problem, the physician must always choose the course best suited to the individual patient and the variables in existence at the moment of decision. These guidelines were developed under the auspices of the American College of Gastroenterology by a committee of experts in the field, reviewed by its Practice Parameters Committee, and approved by the Board of Trustees. The recommendations of these guidelines are therefore considered valid at the time of production based on the data available. New developments in medical research and practice pertinent to each guideline will be reviewed at an established time and indicated at publication to assure continued validity. Owing to the volume of new data on the subject of non-steroidal anti-inflammatory drug (NSAID)-related injury to the upper gastrointestinal tract, i.e., the advent of cyclooxygenase (COX)-2 inhibitors, new data on interactions between these agents, as well as traditional NSAIDs, with aspirin and H. pylori, it was elected by the Committee to confine these guidelines to upper gastrointestinal (GI) injury and to leave post-duodenal injury as the subject of a separate guideline.

The role of H2-receptor antagonists in the prevention of NSAID-induced gastrointestinal damage

Non-steroidal anti-inflammatory drugs (NSAIDs) induce gastric and duodenal damage in animals and humans. The possible protection afforded by cimetidine against acute and short-term NSAID-induced mucosal damage was evaluated in five studies. Cimetidine 200 mg once daily and 400 mg once daily was found to protect the gastric mucosa against damage induced by a single dose of aspirin 1300 mg; this protection was found to be independent of gastric acid secretion. Cimetidine 200 mg q.d.s. was found to protect the stomach and duodenum against damage induced by 14 days' treatment with aspirin 650 mg q.d.s. Duodenal and gastric damage induced during a 7-day treatment period with naproxen 500 mg b.d. was prevented by cimetidine 400 mg b.d.; this dose of cimetidine also provided significant duodenal protection against damage induced by 1 week of therapy with indomethacin 50 mg t.d.s. There is no correlation between upper gastrointestinal symptoms, or between mucosal prostanoids, and the presence or absence of mucosal damage. Cimetidine is therefore effective in the prevention of mucosal damage induced by short-term treatment with NSAIDs.

Non-steroidal anti-inflammatory drug-induced gastroduodenal injury: therapeutic recommendations

Non-steroidal anti-inflammatory drug (NSAID) use is associated with gastro-duodenal erosions and ulcers. Bleeding and perforation are reported complications in NSAID users. Therapeutic recommendations for NSAID-induced gastroduodenal injury are necessary because of our rapidly growing geriatric population, a steady increase in prescriptions for NSAIDs, and the widespread use of over-the-counter NSAIDs. Studies seem to indicate that there is no relationship between acute NSAID-induced mucosal injury and potential damage from chronic NSAID ingestion. Ranitidine (150 mg) b.d. effectively reduces the incidence of duodenal ulcer in NSAID users, but the same dose does not reduce the incidence of gastric ulcer. Misoprostol is effective in reducing the incidence of gastric ulcer in NSAID users, although confirmatory data on its effectiveness in preventing NSAID-induced duodenal ulcer are lacking. In addition to anti-ulcer therapy, treatment of NSAID-induced ulcers includes discontinuing the drug, reducing the dose, or switching to a less potent NSAID. Longer courses of anti-ulcer treatment may be required to achieve expected healing rates when NSAIDs are not discontinued. Results of treatment of NSAID-related ulcers with currently available anti-ulcer medications vary. Several studies have shown that 150 mg ranitidine b.d heals both gastric and duodenal NSAID-induced ulcers. Sucralfate has also been shown to heal NSAID-induced duodenal ulcers. Misoprostol treatment of NSAID-induced ulcers is not well documented, although there are placebo-controlled data that substantiate its benefit in gastric ulcer patients not taking NSAIDs.

Effects of buffered and plain acetylsalicylic acid formulations with and without ascorbic acid on gastric mucosa in healthy subjects

BACKGROUND

The most frequently reported adverse events associated with acetylsalicylic acid intake are minor gastrointestinal complaints. Galenic modifications, such as buffered formulations with or without ascorbic acid, may improve the benefit-risk ratio by decreasing the local mucosal side-effects of acetylsalicylic acid.

AIM

To assess endoscopically-proven gastrointestinal lesions and the amount of gastric microbleeding of four different buffered and plain acetylsalicylic acid formulations, one containing paracetamol.

METHODS

A randomized, four-fold cross-over study was performed in 17 healthy subjects who underwent serial oesophago-gastro-duodenoscopy before and after each course of 4-day dosing. Gastric aspirates were collected for the determination of haemoglobin concentrations to detect microbleeding.

RESULTS

Buffered acetylsalicylic acid plus ascorbic acid yielded the lowest Lanza score, the lowest increase in the number of mucosal petechiae and the lowest increase in the amount of gastric microbleeding. Subjects receiving acetylsalicylic acid plus paracetamol plus caffeine showed the highest Lanza score of all treatments, and a considerably greater sum of petechiae in the oesophagus, stomach and duodenum compared with those receiving buffered acetylsalicylic acid plus ascorbic acid.

CONCLUSIONS

The trial confirms that buffering of acetylsalicylic acid improves local gastric tolerability. Acetylsalicylic acid in combination with ascorbic acid shows significantly fewer gastric lesions and the lowest increase in gastric microbleeding compared with the other tested formulations.

The effect of dosing interval on the efficacy of misoprostol in the prevention of aspirin-induced gastric injury

The effect of twice-daily administration of misoprostol on aspirin-induced gastric injury was evaluated. Twenty-four random-source dogs were divided into groups that received aspirin and misoprostol as follows: group I, aspirin 25 mg/kg PO q8h and placebo PO q8h; group II, aspirin 25 mg/kg PO q8h and misoprostol 3 microg/kg PO q8h; group III, aspirin 25 mg/kg PO q8h, misoprostol 3 microg/kg PO q12h, and placebo PO q24h; and group IV, aspirin 25 mg/kg PO q8h, misoprostol 3 microg/kg PO q24h, and placebo PO q12h for 28 days. Gastroscopy was performed on days -9, 5, 14, and 28. Visible lesions were scored on a scale of 1 (mucosal hemorrhage) to 11 (perforating ulcer). No difference in total score was identified between groups I and IV on any day. Median total scores for groups II and III were significantly (P < or = .05) lower compared to groups I and IV on day 5. Group III had a significantly lower score (P < or = .05) than groups I, II, and IV on day 28. This study suggests that misoprostol 3 microg/kg PO q12h is as effective as misoprostol 3 microg/kg PO q8h in preventing aspirin-induced gastric injury in this model. However, misoprostol 3 microg/ kg PO q8h was less effective in preventing aspirin-induced gastric injury on days 14 and 28 than in previous studies. No difference among numbers of dog-days of vomiting, diarrhea, or anorexia was detected among groups.

Endoscopic evaluation of the gastrotolerance of short-term antalgic treatment with low dose k-diclofenac: a comparison of ibuprofen and aspirin

In a short-term gastro-duodenal endoscopic study in 12 healthy volunteers, the gastrotoxicity was not different after intake of diclofenac-K 12.5 mg (0.33) or ibuprofen 200 mg (0.42, P=0.66) but significantly higher after aspirin 500 mg (2.67, P=0.002).

Gastroduodenal tolerability of medium dose enteric-coated aspirin: a placebo controlled endoscopic study of a new enteric-coated formulation versus regular formulation in healthy volunteers

We compared, in a cross-over study, the toxicity of 300 mg enteric-coated aspirin with regular aspirin used for the prevention of cardiovascular events. In terms of endoscopic haemorrhagic lesions, enteric-coated aspirin is less gastrotoxic than regular aspirin.

Management of gastroduodenal ulcers caused by non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are a major cause of morbidity and mortality, probably resulting in the death of 1200 patients per annum in the UK. The main mechanism of toxicity involves an inhibition of prostaglandin synthesis that results in mucosal erosion as a result of the abrogation of defence mechanisms. However, acid peptic attack can deepen this initial injury. Thus, logical treatments include prostaglandin analogues as 'replacement therapy', acid suppression, enteric coating to avoid topical effects and the use of safer NSAIDs, including those that have little or no effect on gastric mucosal prostaglandin synthesis. There is less logic to the strategy of Helicobacter pylori (H. pylori) eradication, and the status of this approach is controversial. Overall, proton pump inhibitors have the best profile of efficacy and side-effects for the healing and prevention of NSAID-associated ulcers. Misoprostol is also effective and appears to be superior to proton pump inhibitors for superficial erosive injury. Early indications are that selective inhibitors of the inducible cyclooxygenase-2 enzyme have little or no effect in causing ulcers. Growing experience with these agents will probably revolutionize the management of patients with arthritic conditions. However, the increasing use of low-dose aspirin for cardiovascular prophylaxis means that gastroenterologists will have to continue to grapple with the problems of NSAID-associated ulcers for some time to come.

Comparison of the upper gastrointestinal safety of Arthrotec 75 and nabumetone in osteoarthritis patients at high risk for developing nonsteroidal anti-inflammatory drug-induced gastrointestinal ulcers

A 6-week, multicenter, double-masked, placebo-controlled, parallel-group study compared the upper gastrointestinal (UGI) safety of Arthrotec 75 (diclofenac sodium 75 mg-misoprostol 200 microg; G.D. Searle & Co., Skokie, Illinois) administered twice daily with that of nabumetone 1500 mg administered once daily in 1203 patients with symptomatic osteoarthritis (OA) of the hip or knee. All patients had a documented clinical history of endoscopically confirmed gastric, pyloric-channel, or duodenal ulcer or > or = 10 erosions in the stomach or duodenum. UGI endoscopy was performed at baseline and again at week 6 or early withdrawal. Treatment with Arthrotec 75 resulted in a significantly lower combined incidence of endoscopically confirmed gastric and duodenal ulcers compared with nabumetone (4% vs 11%), and its rate of endoscopically confirmed ulceration was equivalent to that of placebo. The incidence of gastric ulcers alone was also significantly lower with Arthrotec 75 than with nabumetone (1% vs 9%). The incidence of duodenal ulcer with Arthrotec 75 was not significantly different from that with nabumetone (4% vs 3%). Types of adverse events were similar for all treatment groups, with GI adverse events predominating. Arthrotec 75 was well tolerated by the majority of patients. The results of this study demonstrate that Arthrotec 75 has a superior UGI safety profile, causing significantly fewer UGI ulcers, in comparison with nabumetone in patients with symptomatic OA and a documented history of ulcers or > or = 10 erosions.

An endoscopic comparison of gastroduodenal injury with over-the-counter doses of ketoprofen and acetaminophen

OBJECTIVE

The objective of this study was to endoscopically assess in healthy subjects the gastrointestinal effects of over-the-counter (OTC) doses of ketoprofen. Ketoprofen is a potent nonsteroidal antiinflammatory agent (NSAID) recently approved for OTC use as an analgesic/antipyretic at doses of 75 mg versus the usual dose of < or = 300 mg daily. In epidemiological studies, ketoprofen at prescription doses has consistently been in the higher relative risk group of NSAIDs in the occurrence of gastrointestinal complications of therapy. The gastrointestinal effects of the OTC (US) dose of ketoprofen have not been reported.

METHODS

In a randomized, double blind, three way crossover study, 24 healthy subjects received 7 days of therapy with ketoprofen 75 mg/day, acetaminophen 4000 mg/day, and placebo. Gastroduodenal endoscopy was performed before and at the end of each treatment period. The condition of the mucosa was graded compositely for the gastric antrum, fundus, body, and duodenum.

RESULTS

Significantly more frequent and severe gastric mucosal injury was observed after dosing with ketoprofen compared with acetaminophen (p = 0.0001). The acetaminophen group showed no difference from placebo (p = 0.8783). Two subjects developed frank gastric ulcers with ketoprofen therapy. Marginally more frequent (p = 0.0703) and significantly more severe (p = 0.0117) duodenal mucosal injury was seen. No significant differences were observed between treatment groups with respect to subjective symptoms of gastric discomfort or adverse events.

CONCLUSION

These results indicate that even at lower (OTC) doses (75 mg/day) ketoprofen is associated with significant gastrointestinal irritation.

Omeprazole 20 or 40 mg daily for healing gastroduodenal ulcers in patients receiving non-steroidal anti-inflammatory drugs

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are strongly associated with gastroduodenal ulcers, and the management of patients with NSAID-associated ulcers represents a common clinical dilemma.

AIM

To assess NSAID-associated ulcer healing during treatment with either standard (20 mg) or high dosage (40 mg) omeprazole.

METHODS

One hundred and sixty-nine patients chronically ingesting diclofenac, ketoprofen, indomethacin or naproxen for osteoarthritis or rheumatoid arthritis, who had abdominal pain and an endoscopically proven gastroduodenal ulcer, were evaluated in a randomized, double-blind, dose regimen trial with omeprazole 20 mg o.m. (n = 81) or omeprazole 40 mg o.m. (n = 88). Ulcer healing was assessed endoscopically at 4 and 8 weeks in the case of unhealed ulcers. Patients continued their usual daily dose of anti-inflammatory medication throughout the study period.

RESULTS

One hundred and fifty-six patients completed the study (77 patients taking 20 mg omeprazole and 79 patients taking 40 mg omeprazole); 12 patients were lost during follow-up and one patient reported an adverse event. Cumulative ulcer intention-to-treat healing rates at 8 weeks were 88% (95% confidence interval (CI) = 79-95%) for the 20 mg omeprazole group and 96.2% (95% CI = 89-99%) for the 40 mg group, and 97.1% (95% CI = 90-100%) for the 20 mg omeprazole group and 98.6% (95% CI = 93-100%) for the 40 mg group by per protocol analysis. There were no statistically significant differences between the two groups. Symptom relief did not differ significantly between the two treatment groups.

CONCLUSION

Both standard and high doses of omeprazole are equally safe and effective regimens for the treatment of NSAID-induced gastroduodenal ulcers when anti-inflammatory treatment is not discontinued.

Misoprostol coadministered with diclofenac for prevention of gastroduodenal ulcers. A one-year study

The objective of this study was to determine the long-term efficacy of misoprostol in preventing diclofenac-induced gastroduodenal ulcers in rheumatoid arthritis and osteoarthritis patients. Three hundred eighty-four patients who had an endoscopically confirmed gastric or duodenal lesion that had healed with misoprostol therapy were randomized to receive misoprostol or placebo coadministered with diclofenac for up to 52 weeks. Endoscopic examinations were repeated at weeks 12, 24, and 52. The development of a gastric and/or duodenal ulcer was considered a prophylaxis failure. Results in the evaluable cohort of patients demonstrated that gastroduodenal ulcer incidences were lower with misoprostol than placebo for all study periods (0-12 weeks, 7% vs 23%; 0-24 weeks, 11% vs 26%; and 0-52 weeks, 15% vs 31%). Misoprostol did not interfere with the antiarthritic effects of diclofenac. In conclusion, misoprostol coadministered with diclofenac for 12 months to patients with rheumatoid arthritis or osteoarthritis significantly reduced the incidence of diclofenac-induced gastroduodenal ulcers (P < or = 0.018).

Disposition of misoprostol and its active metabolite in patients with normal and impaired renal function

The disposition of misoprostol acid, the active metabolite of misoprostol, was studied in 48 subjects with various degrees of renal function after administration of a single 400 microgram oral dose of misoprostol. Subjects were assigned to one of four treatment groups: group 1, normal renal function with creatinine clearance (CLCR) 80-140 mL/min/1.73 m2; group 2, mild renal impairment with CLCR 50-79 mL/min/1.73 m2; group 3, moderate renal impairment with CLCR 20-49 mL/min/1.73 m2 or group 4, end stage renal disease (ESRD) patients maintained on hemodialysis. The maximum plasma concentration (Cmax) and time to reach Cmax (tmax) for misoprostol acid tended to be larger in group 4 subjects; however, it failed to reach statistical significance. Although not statistically significant, in group 4 subjects the terminal half-life (t1/2) of misoprostol acid was almost twice as large (1.27 +/- 0.77 h) as in groups 1, 2, and 3 (0.70 +/- 0.72, 0.72 +/- 0.67, and 0.73 +/- 0.45 h, respectively). Misoprostol acid's total area under the plasma concentration curve (AUC0 infinity) was larger in group 4 subjects (1173.5 +/- 487.4 pg.h/mL) as compared with groups 1, 2, and 3 (421.4 +/- 263.1, 418.9 +/- 114.5, and 377.0 +/- 145.2 pg.h/mL, respectively; P < .05). The apparent total body clearance (CL) of misoprostol acid was statistically significantly smaller in group 4 subjects (0.094 +/- 0.044 L/kg/min) as compared only with group 3 subjects (0.284 +/- 0.102 L/kg/min). The dose of misoprostol may need to be reduced in ESRD patients on prolonged hemodialysis to prevent unnecessary high plasma levels of misoprostol acid and to avoid possible dose-related adverse effects.

Gastrotoxic activity and inhibitory effects on gastric mucosal PGE2 production with different non-steroidal anti-inflammatory drugs: modifications induced by pretreatment with zinc acexamate

Gastrotoxic activities of different non-steroidal anti-inflammatory drugs (NSAIDs) (diclofenac, indomethacin, ketoprofen, naproxen and piroxicam) administered per os were compared with their ability to inhibit gastric prostaglandin E2 (PGE2) synthesis in the rat. In a parallel study, effects of pretreatment with zinc acexamate (ZAC) were also assessed. NSAIDs invariably caused gastric mucosal damage and a decrease of PGE2 levels. A good correlation between the decrease of PGE2 levels and the index of gastric lesion (r = 0.41; p < 0.021) was observed when results obtained with the different NSAIDs were pooled. ZAC pretreatment significantly decreased the overall severity of lesions induced by NSAIDs. However, no correlation between gastric lesion index and depletion of PGE2 gastric levels was observed after treatment with ZAC (r = 0.012; p < 0.948). These data corroborate the hypothesis that preservation of the capability to synthesize endogenous PGs is of critical importance in the maintenance of gastric mucosal integrity. The gastroprotective action observed with ZAC involves alternative mechanisms other than modification of PGE2 levels.

Ranitidine bismuth citrate and aspirin-induced gastric mucosal injury

The aim of this study was to investigate the protective action of a new compound, ranitidine bismuth citrate, in the prevention of aspirin-induced acute mucosal injury to the upper gastrointestinal tract of healthy human volunteers. In a double-blind randomized three-way cross-over study 24 male volunteers received placebo, 900 mg aspirin or 900 mg aspirin and 800 mg ranitidine bismuth citrate at 12-h intervals for nine doses with a 2-week wash-out period between each treatment. The median (interquartile range) number of erosions seen at endoscopy when ranitidine bismuth citrate was given with aspirin (1 [0-4]) was significantly lower than aspirin alone (24 [16-32]) (P < 0.001) and not significantly different from either baseline or placebo (0 [0-2]). These findings were similarly reflected in the effects on microbleeding following the ninth dose: 12.1 (7.1-21.0) microL/10 min following aspirin alone compared to levels with placebo of 1.2 (0.4-2.9), and with aspirin and ranitidine bismuth citrate of 1.6 (0.8-2.6) (P < 0.005). Ranitidine bismuth citrate conferred substantial protection from aspirin-induced injury to the gastric and duodenal mucosa as determined by both endoscopic assessment and microbleeding rates, reducing injury to placebo levels.

Acetylsalicylic acid and misoprostol combination in adjuvant arthritis of rats

The combined effect of acetylsalicylic acid (ASA) and misoprostol (MISO) on adjuvant arthritis was investigated on rats. Alteration by various doses of MISO and fixed dose of ASA was studied. Drugs were given by the nasogastric route each day beginning from the day of adjuvant injection (day 0) and continued until the 16th day. Paw swelling was measured on days 4, 17, and 29, and secondary lesions were assessed on days 17 and 29. Pathological examination of tibiodorsal junction was also evaluated on the 29th day. The results clearly showed that the combination of MISO with ASA did not inhibit the antiinflammatory effect of ASA. Unexpectedly, MISO increased the antiinflammatory effect of ASA at some dosage regimens.

Ketotifen--old drug, new indication: reduction of gastric mucosal injury

The objective of the present study was to determine the efficacy of ketotifen (Zaditen), an effective antiasthmatic drug, in preventing indomethacin-induced gastroduodenal mucosal injury in a two-arm prospective, randomized, double-blind, controlled and open study. Thirty healthy volunteers with endoscopic normal-appearing mucosa were randomly treated, double-blindly, for 1 week with either placebo or ketotifen, 2 mg twice daily. On day 7 indomethacin, 50 mg three times daily, was added. Two subjects, one from each group, were withdrawn from the study owing to non-compliance. Ten additional subjects received ketotifen, 2 mg twice daily, 24 h before indomethacin administration, in an open manner. A second endoscopy was performed 24 h after indomethacin was initiated. Mucosal damage in the stomach and duodenum (hemorrhages, erosions, ulcers) was scored in accordance with Lanza et al. or counted numerically. Adverse reactions were documented. Ketotifen reduced indomethacin-induced gastric mucosal damage, reducing the mean gastric lesion score from 2.85 +/- 0.20 in the placebo-treated group to 1.86 +/- 0.36 and in the subjects pretreated with ketotifen for 7 days. Ketotifen protected (lesion score < or = 1) 6 of 14 subjects pretreated for 7 days, whereas none of the 14 placebo-treated subjects were protected. Ketotifen had no statistically significant protective effects in the duodenum. In the open study lesion scores of patients pretreated with ketotifen for 24 h were similar to those pretreated for 7 days. Ketotifen is effective in the reduction of indomethacin-induced acute gastric mucosal injury. Further studies are required to verify these data in a more relevant clinical setting.

Management of gastroduodenopathy associated with use of nonsteroidal anti-inflammatory drugs

Adverse events associated with the use of nonsteroidal anti-inflammatory drugs (NSAIDs) are reported more frequently to the Food and Drug Administration than are those associated with any other group of drugs. The absolute risk for serious gastrointestinal events--in particular, ulcer bleeding, perforation, and death--is controversial; some investigators believe that an epidemic of NSAID-related complications is being experienced, whereas others suggest that the risks are being overemphasized. The management of patients who take NSAIDs regularly also remains controversial. Key unresolved issues include how best to identify those patients at particularly high risk for the development of ulcer complications and whether such patients should receive prophylactic therapy in an attempt to prevent such problems. In this review, we critically evaluate the currently available literature and present a management algorithm for the treatment and prevention of NSAID-associated gastroduodenopathy.

Expression of gastric antisecretory and prostaglandin E receptor binding activity of misoprostol by misoprostol free acid

In enriched canine parietal cell preparations, misoprostol, an analog of prostaglandin E1 methyl ester, was rapidly deesterified to misoprostol free acid. Under this circumstance, misoprostol and misoprostol free acid exhibited equal antisecretory potency against histamine-stimulated acid secretion and bound equally well to prostaglandin E receptors. When the deesterification of misoprostol was inhibited by paraoxon, an esterase inhibitor, the antisecretory and receptor binding activity of misoprostol was markedly reduced, with potency much less than misoprostol free acid. These results indicate that misoprostol free acid is the active biological form of misoprostol that binds to prostaglandin E receptors and mediates the antisecretory action of misoprostol.

Ranitidine prevents duodenal ulcers associated with non-steroidal anti-inflammatory drug therapy

The results of four similarly designed, randomized, double-blind, placebo-controlled studies conducted to evaluate ranitidine as prophylaxis for NSAID-associated damage are reviewed. A total of 673 patients receiving therapeutic dosages of NSAIDs for arthritic or musculoskeletal conditions also received either ranitidine 150 mg twice daily (n = 343) or placebo (n = 330) for four weeks (two studies) or eight weeks (two studies). Endoscopic grading of mucosal lesions was based on a modified Lanza scoring system. All patients had normal baseline endoscopies. After four weeks of treatment a significant protective effect against duodenal mucosal lesions including duodenal ulcers (three studies) and gastric mucosal lesions including gastric ulcers (one study) was observed in patients who received ranitidine compared with those who received placebo. A meta-analysis of the four studies confirmed that significantly fewer patients receiving ranitidine than placebo developed duodenal ulcers (1% vs. 6%, P = 0.01). Endoscopic data at eight weeks from the two longer-term studies showed that duodenal ulcers occurred in ranitidine- and placebo-treated patients at a rate of 1% (2/137) vs. 8% (10/126) (P = 0.02), respectively, in one trial, and 0% (0/57) vs. 8% (4/49) (P = 0.02), respectively, in the other trial. No protective effect in the stomach was evident at eight weeks. We conclude that ranitidine is effective in preventing NSAID-associated duodenal ulcers and may be appropriate prophylaxis for certain high-risk patients.

Peptic ulcer disease. How to treat it now

Options for treatment of peptic ulcer disease are becoming more diverse. Most new agents are effective yet offer no real advantage over more traditional therapy. However, omeprazole (Prilosec) may be of benefit owing to its potent inhibition of acid secretion, but it is not yet approved for this purpose. Whether treatment of Helicobacter pylori infection will prove beneficial is not yet known, but the answer should be forthcoming. Finally, as with any disease process, alleviation of risk factors is always important. Appropriate counseling regarding use of nonsteroidal anti-inflammatory drugs and cigarette smoking is a necessity.

Endoscopic comparison of cimetidine and sucralfate for prevention of naproxen-induced acute gastroduodenal injury. Effect of scoring method

Nonsteroidal antiinflammatory drug-induced gastroduodenal mucosal damage observed endoscopically is usually categorized as hemorrhages, erosions, or ulcerations. We undertook this study to determine whether the injury produced by a commonly prescribed NSAID, naproxen, could be reduced by cotherapy with sucralfate or cimetidine and to determine how dependent the differences in the degree of protection against mucosal injury measured were on the scoring system used. Four groups of 20 healthy volunteers with endoscopically normal gastric and duodenal mucosa received naproxen (500 mg twice a day) plus cimetidine (300 mg four times a day or 400 mg twice a day), sucralfate (1 g four times a day), or placebo for seven days. After seven days of therapy, a second endoscopy was performed. Separate scoring systems were used for the presence of hemorrhages, erosions, and a combination of both types of injury. There were significantly fewer mucosal hemorrhages present when naproxen and cimetidine were administered than when naproxen was administered with placebo or sucralfate (placebo vs 300 mg cimetidine, P = 0.04, and placebo vs 400 mg cimetidine, P = 0.006, placebo vs sucralfate, P = 0.26). Both cimetidine dosages resulted in significantly fewer hemorrhages than were present following cotherapy of naproxen and sucralfate (P less than 0.05). In contrast, there was no discernible difference in the mucosal injury between placebo and any drug or between any two active therapies when the injury was evaluated based on the presence of gastric erosions.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of enprostil on the gastroduodenal mucosa of healthy volunteers

Enprostil is a synthetic dehydro-prostaglandin E2 with gastroduodenal ulcer-healing and mucosal-protective properties. One hundred and three healthy volunteers were randomized to receive capsules of enprostil 35 micrograms b.d. (the clinically recommended dose), enprostil 70 micrograms b.d., or placebo b.d. All underwent endoscopic assessment of the gastroduodenal mucosa, scored using a 0-4 scale, at baseline and on Days 3, 7, 14, 21 and 28 of dosing. Mean and median maximum scores demonstrated a dose response, and the mean maximum scores were statistically significantly higher for both enprostil groups on each endoscopy day when compared with placebo. The majority of enprostil-treated subjects had petechial haemorrhages. The proportion of volunteers with small white-based mucosal breaks (erosions) was significantly higher for the fundus in the enprostil 70-microgram group on Days 21 and 28 when compared with placebo, but there were no significant differences between treatment groups for any area on the other study days. The 70-microgram dose was associated with significantly more gastrointestinal adverse events than the 35-microgram dose, which was similar to placebo. There were no significant differences between groups for large white-based mucosal breaks (ulcers). We conclude that oral enprostil produced gastric mucosal petechial haemorrhages, primarily in the fundus of the stomach. Gastric mucosal petechial haemorrhages are probably without clinical significance because they are very common in the general population (10-15%) and do not progress to erosions and ulcers.

Preventing upper gastrointestinal bleeding in patients receiving nonsteroidal antiinflammatory drugs

Severe upper gastrointestinal (GI) bleeding is a serious adverse effect of nonsteroidal antiinflammatory drugs (NSAIDs) and the elderly are at increased risk of developing this complication. Bleeding episodes can be prevented. Replacing NSAIDs with acetaminophen may be appropriate when a simple analgesic is needed that eliminates the risk of GI bleeding. Using the lowest effective NSAID dose may decrease the incidence and severity of NSAID gastropathy. Histamine H2-receptor antagonists, sucralfate, and misoprostol have been studied for the prevention of NSAID gastropathy, but only misoprostol prevents mucosal injury in both the stomach and duodenum. Patients who have a history of peptic ulcer disease or gastric bleeding from NSAIDs are candidates for prophylactic measures. Although other patients are at risk, no one knows who should receive prophylactic therapy for NSAID gastropathy. Future studies should attempt to define patient populations that warrant prophylactic therapy.

Prostaglandins and gastric ulcers: from seminal vesicle to misoprostol (Cytotec)

Misoprostol (Cytotec, G.D. Searle & Company, Chicago, IL) is the first of a new class of orally administered prostaglandin analog drugs to be marketed in the United States. Misoprostol was approved for the prevention of gastric mucosal ulcers associated with nonsteroidal anti-inflammatory drugs (NSAIDS) in high-risk patients. This represents a potentially important development in the pharmacotherapy of peptic ulcer disease. The purposes of this article are to review (1) the biochemistry, physiology, and pharmacology of prostaglandins, especially those synthesized by the stomach; (2) the potential role of prostaglandin deficiency in the pathophysiology of gastric ulcer disease; and (3) the role of prostaglandin analogs in the prevention and therapy of gastric ulcer disease and in other conditions. As the mechanism of action of these new drugs differs from that of the histamine H2-receptor antagonists (H2-blockers), prostaglandin analogs will, whenever possible, be compared with the H2-blockers [cimetidine (Tagamet), ranitidine (Zantac), nizatidine (Axid) and famotidine (Pepcid)], currently the cornerstone of peptic ulcer therapy in this country.

Misoprostol: discovery, development, and clinical applications

Misoprostol is a synthetic 15-deoxy-16-hydroxy-16-methyl analog of PGE1, and the first prostaglandin to be registered for the treatment of peptic ulcer disease. Misoprostol is a safe and well-tolerated drug that exerts potent gastric antisecretory effects and mucosal protective actions on the gastric and duodenal mucosa. In a dosage of 800 micrograms daily in two or four divided doses, misoprostol produced rates of complete ulcer healing in both gastric and duodenal ulcer patients significantly superior to placebo and comparable to H2 receptor antagonists. The major adverse effect is diarrhea in about 10% of patients, but this is usually mild and self-limiting. Misoprostol possesses uterotonic activity and should not be used in pregnant women or those who wish to become pregnant. Misoprostol effectively heals and prevents NSAID-induced gastropathy, a therapeutic need previously unserved. Due to its mucosal protective properties, misoprostol may have advantages over antisecretory drugs in the compromised patient who is a chronic smoker or alcohol user, in refractory duodenal ulcer patients, in recurrent ulcer, and in emergency use for acute upper GI bleeding. Misoprostol's tissue-protective effects may also extend to other therapeutic areas.

Prostaglandins and peptic ulcer therapy

The expectation that prostaglandin analogues would improve the ulcer healing abilities of other agents by combining mucosal protection with decreased acid secretion has been proved unwarranted. The ulcer healing capabilities of these drugs reflect their antisecretory potency. A role for these drugs in ulcer healing is questionable but their use has been advocated most strongly to prevent ulceration developing during treatment with non-steroidal anti-inflammatory drugs. While some evidence supports this role, an important clinical benefit of reducing complication rates has yet to be demonstrated.

Mechanisms of gastroprotection

Gastric mucosa is constantly exposed to various irritants, but it usually maintains its integrity owing to several lines of defense, including mucus-alkaline secretion, mucosal hydrophobicity, rich mucosal blood flow, stabilization of tissue lysosomes, maintenance of mucosal sulfhydryls, and rapid proliferation and renewal of mucosal cells. Prostaglandins (PG) inhibit experimental gastric mucosal damage and ulcerations induced by a wide variety of agents, hence PG have been proposed to contribute to the overall protective process by activation of various mucosal defence lines--particularly by prevention of vasocongestion, ischemia, and deep hemorrhagic necrosis. The relation between tissue PG generation and mucosal protection does not appear to be closely related, and probably only minute amounts of PG are required to maintain mucosal integrity. In contrast to PG, other products of arachidonate metabolism, such as TxA2, LTC4 or LTD4, and the related lipid, platelet-activating factor, appear to mediate mucosal damage mainly by the disturbance in mucosal microcirculation and tissue ischemia. Gastroprotection can be achieved by stimulation of mucosal biosynthesis of protective PG or by the inhibition of the release or action of the proulcerogenic arachidonate metabolites. Certain natural substances, such as sulfhydryls, epidermal growth factor, or polyamines, protect the mucosa via a PG-independent mechanism, probably by enhancing the tissue repair processes.(ABSTRACT TRUNCATED AT 250 WORDS)

Misoprostol: a prostaglandin E1 analog with antisecretory and cytoprotective properties

Misoprostol, a methylester analog of prostaglandin E1, with antisecretory and cytoprotective properties, has undergone extensive investigation and has received Food and Drug Administration approval for the prevention of nonsteroidal-induced ulceration. The drug represents the first synthetic, orally active prostaglandin evaluated for the treatment of peptic ulcer disease. Clinical studies reveal a trend toward slightly lower healing rates with misoprostol when compared with histamine (H2)-receptor antagonists in the treatment of gastric and duodenal ulcers. In addition, misoprostol was less effective than H2-blockers in reducing ulcer pain, and caused a higher incidence of adverse reactions, particularly diarrhea occurring in up to 13 percent of the patients treated. Several studies have shown misoprostol to be superior to cimetidine and sucralfate in the prevention of alcohol- and drug-induced gastritis. This report summarizes the biopharmaceutics, pharmacokinetics, and clinical efficacy of misoprostol in the treatment of gastric and duodenal ulcers and in the prevention of mucosal injury.

Effect of ranitidine on gastroduodenal mucosal damage induced by nonsteroidal antiinflammatory drugs

The effect of ranitidine in preventing mucosal damage caused by nonsteroidal antiinflammatory drugs (NSAIDs) was evaluated for eight weeks in a prospective study of 144 patients requiring NSAIDs. Patients with normal endoscopic findings were randomly assigned to receive either ranitidine 150 mg twice daily or placebo for eight weeks, along with either ibuprofen, indomethacin, naproxen, sulindac, or piroxicam. Duodenal damage was significantly less in the ranitidine group compared with the placebo group by weeks 4 and 8 (P less than or equal to 0.01). Duodenal ulcers did not develop in any patients on ranitidine (0/57) compared with 4/49 patients (8%) on placebo (P = 0.02). No significant difference was found between treatment groups with respect to gastric damage; 6/60 (10%) in the ranitidine group compared with 6/50 (12%) in the placebo group developed gastric ulcers. These findings suggest that acid suppression is of greater importance for mucosal protection in the duodenum than in the stomach, where other defense mechanisms may be operative. While ranitidine is an effective prophylaxis for NSAID-induced damage in the duodenum, further studies are needed to define specific risk groups and to assess the potential usefulness of more complete acid suppression in preventing gastric mucosal damage.

Prevention of gastroduodenal injury induced by chronic nonsteroidal antiinflammatory drug therapy

The fact that nonsteroidal antiinflammatory drugs (NSAIDs) damage the gastroduodenal mucosa is now accepted as NSAID use has been associated with a disproportionately high frequency of upper gastrointestinal bleeding and perforation of gastric and duodenal ulcers. More than 10% of patients receiving NSAIDs chronically will have a gastric ulcer on any given day, a point prevalence of ulcer disease 5-10 times higher than in patients who are not taking NSAIDs. Endoscopic studies comparing the effect of acute administration of NSAIDs on the gastroduodenal mucosa in normal volunteers have failed to predict which NSAIDs would be safest when administered chronically. All of the newer NSAIDs appear to be similar in their propensity to cause chronic mucosal damage, including peptic ulceration. Recent studies have suggested that in those starting NSAID therapy, prophylactic cotreatment with H2-receptor antagonists or sucralfate has minimal or no effect on preventing the development of NSAID-induced gastric ulcers, although duodenal ulcers may be reduced. Nonsteroidal antiinflammatory drug-induced gastric ulcers are also not prevented by drug formulations that prevent or markedly reduce the amount of active NSAID in the stomach. Cotreatment with the synthetic prostaglandin misoprostol was associated with a marked reduction in gastric ulcer development in patients with osteoarthritis receiving NSAIDs chronically, suggesting that prevention of prostaglandin generation in the gastric mucosa may play a pivotal role in NSAID-induced gastric ulcers.

How does one demonstrate cytoprotection in man?

The term 'cytoprotection' is discussed. Attempts to demonstrate cytoprotection in human subjects are described and the value and limitations of such human experimental models are explored. Recent trials of prostaglandins in the prevention of gastric damage in arthritic patients are reported. It is concluded that additional clinical trials are needed, not only in peptic ulcer disease but in drug induced gastropathy and stress ulcer. To convincingly demonstrate cytoprotection, direct comparisons with H2 blockers are needed or studies using prostaglandins at dose levels which clearly do not inhibit gastric acid secretion.

A review of mucosal protection by synthetic prostaglandin E analogs against injury by non-steroidal anti-inflammatory agents

Non-steroidal anti-inflammatory agents (NSAIDs) damage the gastric mucosa both in normal volunteers and in arthritic patients. Four large studies have been done in our laboratory comparing the prostaglandin E analog misoprostol against placebo, cimetidine, and sucralfate. These studies showed that misoprostol protected the stomach significantly better than cimetidine or sucralfate. In the duodenum, misoprostol and cimetidine were equally effective. Comparison of secretory and anti-secretory doses of misoprostol reveal duodenal protection with the former but not with the latter, but gastric protection with both doses, suggesting that cytoprotective mechanisms other than acid suppression exist in the stomach in subjects taking prostaglandins. Adequately controlled and blind studies reported in the literature in arthritic patients are also reviewed, and it would appear that prostaglandins offer the best currently available method of providing mucosal protection for patients taking NSAIDs.

Prevention of NSAID-induced gastric ulcer with misoprostol: multicentre, double-blind, placebo-controlled trial

A double-blind, placebo-controlled study was carried out to see whether the synthetic E prostaglandin, misoprostol, would prevent gastric ulcer induced by non-steroidal anti-inflammatory drugs (NSAIDs). 420 patients with osteoarthritis and NSAID-associated abdominal pain were studied; they were receiving ibuprofen, piroxicam, or naproxen. Endoscopy was done at entry and after 1, 2, and 3 months of continuous treatment with 100 micrograms or 200 micrograms misoprostol or placebo, given four times daily with meals and at bedtime, concurrently with the NSAID. Abdominal pain was rated independently by patients and physicians. A treatment failure was defined as development of a gastric ulcer. Gastric ulcers (0.3 cm in diameter or greater) occurred less frequently (p less than 0.001) in both misoprostol treatment groups (5.6% 100 micrograms and 1.4% 200 micrograms) than in the placebo group (21.7%). The significant difference in ulcer formation between the placebo and the misoprostol treatment groups remained when comparisons were restricted to ulcers greater than 0.5 cm in diameter (12.3% placebo, 4.2% 100 micrograms misoprostol, and 0.7% 200 micrograms misoprostol). Mild to moderate, self-limiting diarrhoea was the most frequently reported adverse effect attributed to misoprostol. These results provide the first clear indication that NSAID-induced ulcers are preventable.

Cimetidine decreases indomethacin induced duodenal mucosal damage in patients with acute musculoskeletal disorders

The effect of two doses of cimetidine, 400 mg at night and 400 mg bd, on the protection of indomethacin (50 mg tid) induced mucosal damage was evaluated in a double blind study in patients with acute musculoskeletal disorders. Endoscopic mucosal lesions were scored before and after five to seven days of treatment. One hundred and ninety one patients were endoscoped before the trial, 34 (17.8%) had greater than one erosion and were not recruited. Forty patients were excluded for non-compliance, or lost to follow up. At the second endoscopy, oesophageal, and fundic damage was negligible. Gastric and duodenal lesion score in patients treated with cimetidine 400 mg bd: 2.7 (0.5) (SE); n = 42) was significantly lower (p less than 0.0122) than in placebo treated patients: 6.1 (0.9) (n = 50) or in patients treated with cimetidine 400 mg at night 7.1 (0.8) (n = 21). Cimetidine 400 mg bd provided significant protection for the duodenum, but its protection of antral mucosa did not reach statistical significance. There was no correlation between upper gastrointestinal symptoms and endoscopic findings.

Effects of colloidal bismuth subcitrate on aspirin-induced gastric microbleeding, DNA loss, and prostaglandin formation in humans

Ten healthy young male subjects took part in a double-blind, placebo-controlled, crossover trial to assess the effect of colloidal bismuth subcitrate (De-No) on prostaglandin (PG) E2 generation and mucosal integrity in an aspirin (ASA)-treated stomach. After administration of ASA (2.5 g) plus placebo, a marked reduction in mucosal generation of PGE2 (by about 85%) was observed, and this was accompanied by a significant increase in gastric microbleeding and DNA loss and endoscopic and histologic damage of the mucosa. After the combination of De-Nol (300 mg four times daily) with ASA, mucosal generation of PGE2 showed a reduction similar to that in tests with ASA plus placebo, but gastric microbleeding and mucosal damage were significantly reduced. It is concluded that De-Nol has a protective action on ASA-induced gastric microbleeding and that this protection occurs despite a marked suppression of mucosal production of prostaglandins.

No correlation between indomethacin-induced gastroduodenal damage and inhibition of gastric prostanoid synthesis

The effect of 1 week of treatment with indomethacin 150 mg/day on human gastric prostanoid synthesis was correlated with its effect on gastric and duodenal mucosa. Before and following 1 week of treatment, endoscopic appearance of the mucosa was evaluated and scored. Following 1 week of treatment with indomethacin, antral PGE2 and 6-keto-PGF1 alpha were significantly lower than in normal subjects, but similar in patients with significant or with no mucosal damage. Co-treatment with ranitidine 150 mg b.d. or with cimetidine 400 mg b.d. reduced the mean mucosal damage score but did not affect gastric prostanoid synthesis, which was similar irrespective of the presence or absence of mucosal damage. It is therefore suggested that there is no correlation between indomethacin-induced inhibition of gastric prostanoid synthesis and its induction of mucosal damage.

Double-blind, placebo-controlled endoscopic comparison of the mucosal protective effects of misoprostol versus cimetidine on tolmetin-induced mucosal injury to the stomach and duodenum

Ninety normal volunteers were entered into a double-blind, placebo-controlled study to compare the efficacy of misoprostol (200 micrograms q.i.d.) vs. cimetidine (300 mg q.i.d.) in protecting the gastric and duodenal mucosa from tolmetin-induced (400 mg q.i.d.) injury. After 6 days of treatment, the degree of mucosal injury between treatments was compared by endoscopy, using a predetermined rating scale of 0 (normal mucosa) to 4+ (greater than 25 hemorrhages or erosions or an invasive ulcer). Utilizing a score of less than or equal to 2+ (2-10 hemorrhages or erosions) as a therapeutic success, the overall success rates were 8/30 (26.7%) for placebo, 19/30 (63.3%) for cimetidine, and 27/29 (93.1%) for misoprostol (p less than 0.001). Pairwise comparisons were also significant: misoprostol vs. placebo (p less than 0.001), misoprostol vs. cimetidine (p = 0.006), and cimetidine vs. placebo (p = 0.004). A separate analysis of the gastric scores alone revealed success rates identical to those in the overall evaluation; however, success rates in the duodenum for both misoprostol (29/29) and cimetidine (29/30) were extremely high and did not differ. It is concluded that misoprostol is highly effective and significantly better than cimetidine in protecting the gastric mucosa from tolmetin-induced injury; however, both agents were highly protective in the duodenum.

Aspirin-induced human antral injury is reduced by vodka pretreatment

Mild irritants have been shown to protect the rat gastric mucosa against noxious agents. This study was designed to test the protective potential of low-dose ethanol against acetylsalicylic acid (ASA) -induced gastric injury. Ten healthy volunteers who were nondrinkers and had normal baseline upper gastrointestinal endoscopy participated in a randomized double-blind crossover study. Thirty minutes after either vodka (37.5 ml) in tomato juice or tomato juice alone, each subject took 975 mg ASA and then underwent endoscopy 1 hr later. The degree of mucosal injury was scored, and blood was taken for ethanol and salicylate levels. There was a washout interval of seven days between the two treatments. Endoscopic scores were analyzed using the sign test. After a single dose of ASA, mucosal injury was confined to the fundus and antrum, while the duodenum was minimally affected. A significant reduction in antral damage was seen with ethanol pretreatment (P less than 0.05). The same trend was evident in the fundus but did not achieve statistical significance. Serum salicylate levels averaged 13.2 +/- 0.8 mg/100 ml and were not different between the two treatments. Ethanol concentration ranged from 1.1 to 6.2 mmol/liter following the vodka drink and was 0 after the placebo.

Role of H2-receptor blockers in the prevention of gastric injury resulting from nonsteroidal anti-inflammatory agents

Nonsteroidal anti-inflammatory drugs (NSAIDs) can produce injury to the gastric and duodenal mucosa. The histamine (H2)-receptor blocker cimetidine was studied to determine whether protection of the gastric mucosa of normal volunteers could be provided against a single dose of aspirin, 1,300 mg. Gastric mucosal injury was assessed with gastroscopy performed two hours after aspirin intake. Three liquid cimetidine doses were administered over 24 hours prior to the aspirin dose, the last dose one hour before the aspirin. The 200-mg and 400-mg doses of cimetidine protected a sufficient number of subjects to warrant further study. In the second study, these two doses were further examined to determine whether three doses were necessary and whether the final dose could be coadministered with the aspirin instead of one hour before. Concomitant administration of a single dose of cimetidine with aspirin was found to protect the gastric mucosa from aspirin damage as effectively as the other cimetidine regimens employed. A final, double-blind comparison of cimetidine, 200 mg, with placebo administered with the aspirin, 1,300 mg, confirmed that cimetidine protected the gastric mucosa from the hemorrhagic effects of aspirin.