Use of microbleeding and an ultrathin endoscope to assess gastric mucosal protection by famotidine

A fixed dose combination of ibuprofen and famotidine

The NSAID class of medications is frequently used for mild to moderate pain. While overall safe, NSAIDs have several important adverse effects including esophageal, gastric and duodenal ulceration which limit their use. This has led to the development of NSAIDs with either less gastrointestinal side effects or concurrent use of medications to prevent NSAID gastrointestinal side effects. While several classes of medications exist for the prevention of gastrointestinal side effects, few combination treatments are available in a single pill. Towards this end, a combination pill of ibuprofen and famotidine (HZT-501, Horizon Therapeutics, Skokie, IL. USA) has been developed.

Famotidine for the prevention of peptic ulcers and oesophagitis in patients taking low-dose aspirin (FAMOUS): a phase III, randomised, double-blind, placebo-controlled trial

BACKGROUND

There are few therapeutic options for the prevention of gastrointestinal mucosal damage caused by low-dose aspirin. We therefore investigated the efficacy of famotidine, a well-tolerated histamine H(2)-receptor antagonist, in the prevention of peptic ulcers and erosive oesophagitis in patients receiving low-dose aspirin for vascular protection.

METHODS

Adult patients (aged >/=18 years) from the cardiovascular, cerebrovascular, and diabetes clinics at Crosshouse Hospital, Kilmarnock, UK, were eligible for enrolment in this phase III, randomised, double-blind, placebo-controlled trial if they were taking aspirin 75-325 mg per day with or without other cardioprotective drugs. Patients without ulcers or erosive oesophagitis on endoscopy at baseline were randomly assigned by computer-generated randomisation sequence to receive famotidine 20 mg twice daily (n=204) or placebo twice daily (n=200). Patients had a final endoscopic examination at 12 weeks. The primary endpoint was the development of new ulcers in the stomach or duodenum or erosive oesophagitis at 12 weeks after randomisation. Analysis was by intention to treat, including all randomised patients who received at least one dose of study drug (famotidine or placebo). This trial is registered as an International Standard Randomised Clinical Trial, number ISRCTN96975557.

FINDINGS

All randomised patients received at least one dose and were included in the ITT population. 82 patients (famotidine, n=33; placebo, n=49) did not have the final endoscopic examination and were assumed to have had normal findings; the main reason for participant withdrawal was refusal to continue. At 12 weeks, comparing patients assigned to famotidine with patients assigned to placebo, gastric ulcers had developed in seven (3.4%) of 204 patients compared with 30 (15.0%) of 200 patients (odds ratio [OR] 0.20, 95% CI 0.09-0.47; p=0.0002); duodenal ulcers had developed in one (0.5%) patient compared with 17 (8.5%; OR 0.05, 0.01-0.40; p=0.0045); and erosive oesophagitis in nine (4.4%) compared with 38 (19.0%; OR 0.20, 0.09-0.42; p<0.0001), respectively. There were fewer adverse events in the famotidine group than in the placebo group (nine vs 15); four patients in the placebo group were admitted to hospital with upper gastrointestinal haemorrhage. The other most common adverse event was angina (famotidine, n=2; placebo, n=4).

INTERPRETATION

Famotidine is effective in the prevention of gastric and duodenal ulcers, and erosive oesophagitis in patients taking low-dose aspirin. These findings widen the therapeutic options for the prevention of gastrointestinal damage in patients needing vascular protection.

FUNDING

Merck Laboratories and Astellas Pharma.

Non-steroidal anti-inflammatory drugs: who should receive prophylaxis?

Non-steroidal anti-inflammatory drugs (NSAIDs) are the major recognized cause of iatrogenic disease, and may cause 100 000 deaths per annum through peptic ulcer complications. A number of risk factors can be identified that indicate patients at high risk. These patients can be managed by substitution of a COX-2 inhibitor or by prophylaxis with a proton pump inhibitor (PPI). Because risk factors that render patients at high risk of ulcer complications also act in the absence of NSAID use, PPI prophylaxis (or Helicobacter pylori eradication where H. pylori is the risk factor) have much to offer and controlled studies show that the incidence of recurrent peptic ulcer bleeding can be reduced substantially by PPI co-administration. Substitution of COX-2 inhibitors also has much to offer, arguably most in those without risk factors (although regulatory authorities do not accept this argument). Recent data show that PPI and COX-2 inhibitors can play complementary roles in the management of patients with moderate to severe dyspepsia and at high risk of ulcer complications.

[Mucosa protective therapy with long-term nonsteroidal antirheumatic drugs]

Due to the extraordinary high prevalence of peptic lesions in the upper gastrointestine in the long-term treatment with nonsteroidal anti-inflammatory drugs, a prophylaxis in patients belonging to high-risk groups is essential. Misoprostol, proton pump inhibitors and histamine 2-receptor antagonists have been evaluated in prospective studies. The efficacy of Misoprostol is well documented, though its use in prevention is frequently limited due to side effects. Proton pump inhibitors are also well established, especially in the therapy of nonsteroidal anti-inflammatory drugs associated peptic ulcers and in consecutive secondary prevention. The histamine 2-receptor antagonist Famotidine in a high oral dosage is able to reduce the frequency of peptic lesions too, but not to the same degree as Misoprostol and proton pump inhibitors. It is very likely that helicobacter pylori eradication without any further mucosaprotective therapy will only decrease the incidence of upper gastrointestinal bleeding in low dose Aspirin application. In spite of controversial studies this eradication seems to be a useful additional therapy for ulcer prophylaxis in high risk groups. Selective Cyclooxygenase-2 inhibitors may become a promising alternative, from a pathophysiological perspective. However, to date there has been a lack of clear comparative studies with common nonsteroidal anti-inflammatory drugs plus mucosaprotecting agents. Daily therapy costs are higher with a Cyclooxygenase-2 inhibitor than using the traditional nonsteroidal anti-inflammatory drugs together with either proton pump inhibitors, histamine 2-receptor antagonists or Misoprostol--a fact that should be considered in primary therapeutic decisions. In the following review we will present the most important results of the different prophylactic and therapeutic modalities. On the basis of placebo-controlled, prospective studies on the one hand and the recommendations of the scientific societies on the other, a guideline for daily clinical practice will be suggested.

Questions regarding future research on aspirin and the gastrointestinal tract

Despite great proven and potential benefits, aspirin also has adverse side effects on all parts of the gastrointestinal tract including ulceration, bleeding, perforation, and stenosis. Because of widespread and growing use, there is a need to understand and, if possible, prevent the adverse effects of aspirin while maintaining its benefits. This article is part of a report from a consensus meeting in 1999 on nonsteroidal anti-inflammatory drugs, and examines possible mechanisms of each of the risks of normal and low-dose aspirin use including areas of uncertainty. Based on these issues, we recommend studies that would further clarify the actions of aspirin. We also examine various strategies that might be used to prevent or mitigate adverse effects. Finally, we propose future research prospects in the search for a safer 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.

Personal review: Helicobacter pylori, NSAIDs and cognitive dissonance

Helicobacter pylori and non-steroidal anti-inflammatory drugs (NSAIDs) each cause peptic ulcers but by different mechanisms. As a result, the effect of both of these risk factors together is not a synergistic enhancement of injury, ulceration or rates of complications. Indeed, there are circumstances under which patients infected with H. pylori are less prone to NSAID-induced ulcers than those who are not infected or who have undergone eradication treatment. This may be because of opposite effects on gastric mucosal prostaglandin synthesis or for other reasons. Reluctance to accept that there may be specific circumstances where H. pylori is beneficial may arise because of the psychological process of cognitive dissonance.

Protection of human gastric mucosa against aspirin-enteric coating or dose reduction?

BACKGROUND

Aspirin is widely used for cardiovascular prophylaxis.

AIM

To compare the effectiveness of two widely-used strategies-dose reduction and enteric coating-for the minimization of gastric mucosal injury or toxicity.

METHODS

Twelve healthy volunteers were studied. On four separate occasions each received, under blinded conditions, five daily doses of plain aspirin 300 mg, plain aspirin 75 mg, enteric-coated aspirin 300 mg or placebo. Ex vivo prostaglandin E2 synthesis was stimulated by the vortex mixing of gastric mucosal biopsies in Tris saline and measured by radioimmunoassay. Mucosal injury was quantified both by counting erosions and with a visual analogue scale.

RESULTS

All three preparations reduced prostaglandin E2 synthesis by day five, by (median) 84% for plain aspirin 300 mg, by 80% for enteric coated aspirin 300 mg and by 63% for plain aspirin 75 mg. There was little mucosal injury prior to the start of each dose and period and no significant change with placebo. Plain aspirin caused a dose-dependent mucosal injury, with two (median, IQR 0-7) gastric erosions after five days of plain aspirin 75 mg, and 18 (2-26) after five days of plain aspirin 300 mg. With enteric-coated aspirin 300 mg there were 0 (0-1) gastric erosions (P = 0.003 compared to plain aspirin 300 mg P = 0.11, compared to plain aspirin 75 mg).

CONCLUSION

Enteric coated aspirin reduces acute gastric mucosal injury to placebo levels, despite its inhibition of prostaglandin synthesis. Enteric coating is an appropriate strategy for the prevention of gastric mucosal damage induced by low-dose aspirin, which warrants systematic clinical evaluation.

Proton pump inhibitors. Pharmacology and rationale for use in gastrointestinal disorders

Proton pump inhibitors (PPIs) are drugs which irreversibly inhibit proton pump (H+/K+ ATPase) function and are the most potent gastric acid-suppressing agents in clinical use. There is now a substantial body of evidence showing improved efficacy of PPIs over the histamine H2 receptor antagonists and other drugs in acid-related disorders. Omeprazole 20 mg/day, lansoprazole 30 mg/day, pantoprazole 40 mg/day or rabeprazole 20 mg/day for 2 to 4 weeks are more effective than standard doses of H2-receptor antagonists in healing duodenal and gastric ulcers. Patients with gastric ulcers should receive standard doses of PPIs as for duodenal ulcers but for a longer time period (4 to 8 weeks). There is no conclusive evidence to support the use of a particular PPI over another for either duodenal or gastric ulcer healing. For Helicobacter pylori-positive duodenal ulceration, a combination of a PPI and 2 antibacterials will eradicate H. pylori in over 90% of cases and significantly reduce ulcer recurrence. Patients with H. pylori-positive gastric ulcers should be managed similarly. PPIs also have efficacy advantages over ranitidine and misoprostol and are better tolerated than misoprostol in patients taking nonsteroidal anti-inflammatory drugs (NSAIDs). In endoscopically proven gastro-oesophageal reflux disease, standard daily doses of the PPIs are more effective than H2-receptor antagonists for healing, and patients should receive a 4 to 8 week course of treatment. For severe reflux, with ulceration and/or stricture formation, a higher dose regimen (omeprazole 40 mg, lansoprazole 60 mg, pantoprazole 80 mg or rabeprazole 40 mg daily) appears to yield better healing rates. There is little evidence that PPIs lead to resolution of Barrett's oesophagus or a reduction of subsequent adenocarcinoma development, but PPIs are indicated in healing of any associated ulceration. In Zollinger-Ellison syndrome, PPIs have become the treatment of choice for the management of gastric acid hypersecretion.

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.

Progress in prophylaxis against nonsteroidal anti-inflammatory drug-associated ulcers and erosions. Omeprazole NSAID Steering Committee

Four large clinical studies have shown that omeprazole, 20 mg once daily, is effective in preventing the significant gastroduodenal consequences of nonsteroidal anti-inflammatory drugs (NSAIDs). In the Scandinavian Collaborative Ulcer Recurrence (SCUR) study, patients were randomized (without initial endoscopy) to receive omeprazole or placebo for up to 3 months. Of the patients treated with omeprazole, 24.7% experienced treatment failure, compared with 50.0% of those on placebo. Fewer patients in the omeprazole group than in the placebo group developed a peptic ulcer (4.7% versus 16.7%, respectively) or dyspeptic symptoms (8.2% versus 20.0%, respectively). In the Omeprazole versus Placebo as Prophylaxis of Ulcers and Erosions from NSAID Treatment (OPPULENT) study, patients were also randomized to receive omeprazole or placebo. The estimated probability of remaining in remission for 6 months while receiving omeprazole was 0.78, compared with 0.53 for placebo. Fourteen (16.5%) patients on placebo developed peptic ulcer(s), compared with three (3.6%) patients on omeprazole. The Omeprazole versus Misoprostol for NSAID-Induced Ulcer Management (OMNIUM) study consisted of a healing and a prophylactic phase. Patients who successfully completed the healing phase were re-randomized to receive omeprazole, misoprostol, or placebo for up to 6 months. In patients receiving omeprazole, 36.5% experienced treatment failure, compared with 48.6% of those on misoprostol, and 67.7% of those on placebo. Omeprazole and misoprostol appeared to be equally effective in preventing gastric ulcer; by contrast, omeprazole was highly effective in preventing duodenal ulcer, when compared with misoprostol and placebo. The Acid Suppression Trial: Ranitidine versus Omeprazole for NSAID-Associated Ulcer Treatment (ASTRONAUT) study also consisted of a healing and a prophylactic phase. Patients who successfully completed the healing phase were re-randomized to receive omeprazole or ranitidine for up to 6 months. In patients receiving omeprazole, 26.2% experienced treatment failure, compared with 37.7% of those on ranitidine. The percentages of patients with a peptic ulcer relapse were 5.7% for omeprazole and 19.5% for ranitidine. The data show that omeprazole is an effective and well-tolerated agent for both primary and secondary (maintenance) prophylaxis in patients receiving NSAIDs.

Primary gastroduodenal prophylaxis with omeprazole for non-steroidal anti-inflammatory drug users

AIM

To investigate the efficacy of omeprazole 20 mg o.m. as primary prophylaxis against non-steroidal anti-inflammatory drug (NSAID)-associated ulcer disease or dyspeptic symptoms.

METHODS

A parallel group study compared patients randomized to receive omeprazole 20 mg o.m. or placebo as co-therapy with on-going NSAID treatment, over 6 months, in 19 specialist centres in Ireland, Hungary, France, the UK and the USA. One hundred and sixty-nine patients taking NSAIDs regularly, chronically and above defined minimum doses entered the trial. The main outcome measure was the development of gastric or duodenal ulcers detected endoscopically, the development of multiple erosions in the stomach or duodenum, or the onset of moderate or severe dyspeptic symptoms.

RESULTS

The estimated probability of remaining free of these end-points for 6 months for patients taking omeprazole was 0.78 compared to 0.53 for placebo (P = 0.004). Fourteen patients receiving placebo (16.5%) developed 15 ulcers, comprising nine gastric and six duodenal ulcers, compared to three patients (3.6%) receiving omeprazole (all gastric ulcers). Logistic regression analysis showed that older patients were less likely, whilst those with rheumatoid arthritis were more likely, to remain free of NSAID-associated problems.

CONCLUSIONS

Omeprazole is an effective agent for gastroduodenal prophylaxis in patients taking NSAIDs. Its main effect is to reduce the rate of development of gastric and duodenal ulcers.

Famotidine for the prevention of gastric and duodenal ulcers caused by nonsteroidal antiinflammatory drugs

BACKGROUND

Acid suppression with famotidine, a histamine H2-receptor antagonist, provides protection against gastric injury in normal subjects receiving short courses of aspirin or naproxen. The efficacy of famotidine in preventing peptic ulcers in patients receiving long-term therapy with nonsteroidal antiinflammatory drugs (NSAIDs) is not known.

METHODS

We studied the efficacy of two doses of famotidine (20 mg and 40 mg, each given orally twice daily), as compared with placebo, in preventing peptic ulcers in 285 patients without peptic ulcers who were receiving long-term NSAID therapy for rheumatoid arthritis (82 percent) or osteoarthritis (18 percent). The patients were evaluated clinically and by endoscopy at base line and after 4, 12, and 24 weeks of treatment. The evaluators were unaware of the treatment assignment. The primary end point was the cumulative incidence of gastric or duodenal ulceration at 24 weeks.

RESULTS

The cumulative incidence of gastric ulcers was 20 percent in the placebo group, 13 percent in the group of patients receiving 20 mg of famotidine twice daily (P = 0.24 for the comparison with placebo), and 8 percent in the group receiving 40 mg of famotidine twice daily (P = 0.03 for the comparison with placebo). The proportion of patients in whom duodenal ulcers developed was significantly lower with both doses of famotidine than with placebo (13 percent in the placebo group, 4 percent in the low-dose famotidine group [P = 0.04], and 2 percent in the high-dose famotidine group [P = 0.01]). Both doses of famotidine were well tolerated.

CONCLUSIONS

Treatment with high-dose famotidine significantly reduces the cumulative incidence of both gastric and duodenal ulcers in patients with arthritis receiving long-term NSAID therapy.

Non-steroidal anti-inflammatory drug gastropathy: causes and treatment

Aspirin and non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs) almost invariably cause acute gastroduodenal injury and probably account for approximately 12,000 ulcer bleeding episodes and 1200 deaths per annum in the United Kingdom. Clinically significant intestinal toxicity is also recognized but less clearly defined. The main risk factors for NSAID-related peptic ulcer complications are age, past history, use of higher risk individual NSAIDs, drug dose, concurrent use of warfarin or corticosteroids. The underlying reason for NSAID use and Helicobacter pylori status is not clearly associated with increased risk. Whether NSAIDs cause drug-induced non-ulcer dyspepsia is also controversial. Acute injury occurs more readily with aspirin than with non-aspirin NSAIDs, and the spectrum of acute injury is of little value in predicting clinically significant end points in comparison with different NSAIDs. However, acute studies of co-prescribed protective agents are highly predictive of performance in clinical practice. Gastric mucosal integrity is maintained by the interplay of three protective networks: prostaglandin synthesis, nitric oxide synthesis and the activity of the enteric nervous system. Aspirin and NSAIDs act by inhibiting prostaglandin synthesis catalysed by two cyclooxygenase enzymes. Most existing NSAIDs are unselective and inhibit the activity of the constitutive cyclooxygenase (COX) 1 enzyme in the stomach as much as the cyclooxygenase (COX) 2 enzyme which is induced at sites of inflammation such as joint disease. There are, however, prospects for selective cyclooxygenase 2 inhibitors. Some NSAIDs, particularly aspirin, have additional topical toxicity, which may in part reflect mucosal trapping. Some data favor an effect of NSAIDs in inhibiting mitochondrial oxidative phosphorylation. The principal physiological mechanisms which are compromised by NSAID use are mucosal blood flow, secretion of mucus and bicarbonate and maintenance of a hydrophobic mucosal surface. Animal data suggest that polymorphonuclear leukocytes (PMNs) are important for acute damage though the relevance to humans has yet to be established. As well as damaging the mucosa, NSAIDs impair ulcer healing and are associated with reduced epithelial proliferation and evidence of diminished angiogenesis. An interaction between prostaglandins and growth factors, as well as the synthesis of antiproliferative products of arachidonic acid metabolism may be involved. Healing of NSAID ulcers by conventional doses of H2 antagonists is slow and H2 antagonists are poor at preventing gastric ulcer development or recurrence. These problems can be overcome by the use of more potent acid suppression. Misoprostol heals NSAID-associated ulcers, though whether healing is as fast as with non-NSAID ulcers has not been formally established. Misoprostol is effective prophylactic treatment but has a significant incidence of adverse events, particularly diarrhoea. Misoprostol has been reported to prevent ulcer complications, and in endoscopic studies has been superior as prophylaxis to standard dose ranitidine. Results of its efficacy compared to proton-pump inhibitors are awaited. For many patients appropriate management is avoidance of NSAIDs or use of less potent/toxic alternatives such as ibuprofen. Reductions in prescribing arising from a prior authorization scheme show that this can be achieved. For high-risk patients requiring continuing NSAID use co-prescription of omeprazole or misoprostol should be considered.

Gastric microbleeding following single and repeated dosing with naproxen

BACKGROUND

Adaptation to gastric damage from nonsteroidal anti-inflammatory drugs (NSAID) has been observed during ongoing dosage in rats and humans. However, this does not always occur, and our previous data suggest that NSAID half-life may be a determining factor.

AIM

To investigate whether adaptation occurs during 1 week of naproxen administration in humans.

SUBJECTS

Thirteen healthy volunteers were studied at baseline, and after one or seven daily doses of naproxen 750 mg. Gastric microbleeding was measured 4 h after naproxen in gastric washings collected during a 30-min period. Serum thromboxane B concentrations were also assayed, as a marker of cyclo-oxygenase inhibition.

RESULTS

Mean blood loss after placebo was 0.60 microL/10 min (95% CI: 0.21-0.98). This rose to 2.15 (0.73-3.57) and 1.75 (0.74-2.76) microL/10 min after one and seven daily doses of naproxen, respectively (P < 0.05 vs. baseline; day 1 vs. 7 not significant). Thromboxane B concentrations were < 10% of control at both day 1 and 7 of dosing.

CONCLUSION

In accord with our findings in rats, adaptation to this moderately long acting NSAID in humans was not apparent. We conclude that any adaptation to naproxen is unlikely to be clinically important.

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.

Placebo-controlled comparison of piroxicam-beta-cyclodextrin, piroxicam, and indomethacin on gastric potential difference and mucosal injury in humans

The acute gastroduodenal mucosa injury and gastric potential difference (GPD) drops provoked by 14-day administration of 20 mg/day of a new piroxicam formulation (piroxicam-beta-cyclodextrin), 20 mg/day standard piroxicam and 100 mg/day indomethacin were evaluated and compared in a randomized, double-blind, placebo-controlled study carried out on 64 volunteers. Endoscopic examinations, performed after 14-day treatment, demonstrated that piroxicam-beta-cyclodextrin was less gastrolesive (mean endoscopic score +/- SE = 0.56 +/- 0.2) than either piroxicam (2.06 +/- 0.5) or indomethacin (2.25 +/- 0.5) (p < 0.01). The drop in GPD after a single dose of the assigned drug was considerably greater for piroxicam and indomethacin than for piroxicam-beta-cyclodextrin (p < 0.01), which registered similar values to placebo. Since GPD is an expression of the anatomo-functional integrity of the gastric barrier, the results indicate that piroxicam-beta-cyclodextrin exerts less direct acute damage on the gastric mucosa. Therefore, when administered short-term, piroxicam-beta-cyclodextrin appears to be less gastrolesive than either indomethacin or the standard piroxicam formulation.

Interaction between heparin and acetylsalicylic acid on gastric mucosal and skin bleeding in humans

The haemorrhagic effect of unfractionated heparin and of the low molecular weight heparin, enoxaparin, on gastric mucosal bleeding induced by acetylsalicylic acid (ASA) and on skin bleeding induced by the Simplate technique was investigated in healthy human volunteers. Endoscopic estimation of gastric bleeding by visual analogue scores was more sensitive than biochemical quantitation of blood in the gastric washing by a modified HaemoQuant method. Contrary to what was expected, the ASA-induced gastric mucosal bleeding was not increased by heparin pretreatment, whereas heparin in combination with ASA, but not ASA alone, significantly increased the skin bleeding time. In the interaction with ASA, enoxaparin and unfractionated heparin appeared to act similarly.