Epidemiological evidence for the association of aspirin and acute gastrointestinal bleeding

Aspirin and bleeding peptic ulcers in the elderly

A case-control study was performed to determine whether aspirin confers a similar risk of bleeding from gastric or duodenal ulcers in the elderly as non-aspirin, non-steroidal anti-inflammatory drugs. The intake of analgesics in 230 patients with bleeding ulcers aged 60 and over and in hospital and community controls matched for age and sex was examined. Those who had taken aspirin were between two and three times more likely to be admitted to hospital with bleeding ulcers. This increased risk was not accounted for by aspirin taken for indigestion or by concurrent use of non-aspirin, non-steroidal anti-inflammatory drugs. A similar effect was not seen for paracetamol. When aspirin and other non-steroidal anti-inflammatory drugs were considered together the overall risk attributed to the drugs suggested that these drugs may be responsible for over a third of admissions for bleeding peptic ulcers in the elderly.

Management of NSAID-induced gastrointestinal lesions

Mucosal lesions in the g.i. tract due to ASA and other nonsteroidal anti-inflammatory drugs are well-known in clinical practice. Though the gastroduodenal mucosa is the area most commonly investigated, several recent reports focus on lesions in the small and large intestine as well. Despite considerable efforts in the field, none of the new substances developed in the past few years have proven convincingly superior to existing drugs. Instead, other approaches are being evaluated: Bypassing of the gastroduodenal mucosa through enteric coating and slow release formulations have been suggested, but the possibility of transferring the deleterious effects to distal parts of the gastrointestinal tract by such formulation modifications calls for extensive evaluation of this area, before these formulations can be applauded as advantageous in this group of patients. Co-administration of protective substances has also been advocated, and, despite somewhat contradictory results, protection has been reported by H2-antagonists alone or in combination with antacids, as well as by cytoprotective agents like Sucralfate, and prostaglandin analogues.

Drug treatment of pain in rheumatoid disorders

The relief of pain remains a delicate balance between the potential toxicity and desired effect of currently available compounds. Physician and patient need to make the optimum use of such therapies. Control of pain and stiffness in rheumatic diseases is a dynamic process. There is a constant need for re-appraisal of aims and objectives and adjustment of treatment according to variations in disease and response. Where 'specific' therapy is available, it is clearly preferable to use it rather than employ large doses of purely symptom-relieving drugs. At present toxicity is inextricably linked to efficacy, and dissociation of these two factors seems unlikely to be achieved in the near future. More efficient 'targeting' of drugs at the site of desired action should help to minimize the adverse effects of therapy. Ultimately the most efficient way of relieving pain and stiffness will be to prevent or suppress the inflammatory disorders which give rise to the symptoms. Unfortunately this is an elusive goal at present.

Symptoms in patients with peptic ulcer and hematemesis and/or melena related to the use of non-steroid anti-inflammatory drugs

One hundred and seven consecutive patients with hematemesis and/or melena and a diagnosis of duodenal, gastric, or esophageal ulcers were interviewed immediately before or after endoscopy about the use of non-steroid anti-inflammatory drugs (NSAIDs) and symptoms before the hemorrhage. If the patients admitted no symptoms of abdominal pain or discomfort, nausea, vomiting, or heartburn, they were classified as having no ulcer symptoms before the hemorrhage. Patients who had not taken NSAIDs during the last 48 h before the hemorrhage were classified as not having taken NSAIDs. Significantly fewer patients had ulcer symptoms in the group that had used NSAIDs than in the other group (p less than 0.01). This may be interpreted as a possible masking effect by NSAIDs on ulcer symptoms. Physicians and patients should be aware of this possible effect of NSAIDs.

Non-steroidal anti-inflammatory drugs and peptic ulcer perforation

A retrospective study is reported in which the ingestion of non-steroidal anti-inflammatory drugs (NSAID) in 269 patients with perforated peptic ulceration and 269 age/sex matched controls admitted between 1973-1982 was compared. A highly significant statistical difference was found (p less than 0.001) in those aged over 65. There was no statistical difference, however, in those aged under 65. Furthermore we have shown a highly statistically significant correlation (p less than 0.0001) between the annual number of patients aged over 65 with perforated peptic ulcers taking NSAID and the annual number of prescriptions issued for these drugs in the region. No such correlation was found for patients aged under 65 years. We suggest that the elderly especially women are unduly susceptible to NSAID associated peptic ulcer perforation, and discuss factors that may account for this.

A controlled endoscopic study comparing the toxic effects of sulindac, naproxen, aspirin, and placebo on the gastric mucosa of health volunteers

Sixty volunteers were endoscopically evaluated to compare gastric mucosal injury following oral administration of sulindac, naproxen, aspirin, or placebo for two consecutive seven-day periods. A single-blind technique was utilized wherein the endoscopist was unaware which drug each volunteer had received. The following dosages were employed for the two study periods: sulindac, 150 and 200 mg, b.i.d., naproxen, 250 and 375 mg, b.i.d., and aspirin, 650 and 975 mg, q.i.d. The only subject who developed a frank ulcer with mucosal bleeding was in the sulindac group, however volunteers taking sulindac demonstrated statistically less significant mucosal injury on endoscopic examination than those receiving naproxen or aspirin.

Aspirin, paracetamol, and haematemesis and melaena

Aspirin and paracetamol consumption have been compared in 346 matched pairs of patients with haematemesis and melaena, and control individuals in the general community. Both aspirin and paracetamol intake were more common in patients than in controls, but the association for aspirin was stronger and was apparent with both recent and habitual intake, whereas for paracetamol the association was not detectable for habitual intake. The results for paracetamol suggests that patients with bleeding take analgesic drugs in part because of symptoms associated with bleeding, and such intake is not necessarily causal of bleeding. Failure to control investigations to take account of this point has exaggerated the possible risks of aspirin consumption.

Reappraisal of the effects of aspirin on the stomach

In a survey of the published evidence linking aspirin ingestion to gastric mucosal damage an attempt has been made to assess the role of aspirin in the pathogenesis of acute and chronic gastric haemorrhage and peptic ulceration. It seems that aspirin ingestion rarely causes clinically significant gastric damage in normal subjects and then usually only with large or frequent doses. Even in these rare instances the specific role of aspirin remains uncertain.

Gastroscopic evaluation of anti-inflammatory agents

Gastroscopy was performed in 164 patients with rheumatoid arthritis (RA) and 85 with osteoarthritis (OA) to assess the effects of anti-inflammatory agents on the stomach. The main criterion for entry into the trial was the absence of active gastric lesions on pretreatment endoscopy. The patients were divided into groups to receive one of 12 anti-inflammatory drugs or combinations of these. Gastroscopy repeated at three to six and at 12 months disclosed gastric lesions in 78 cases (31%), patients in both disease categories being similarly affected. Lesions occurred in 41 of the 177 patients (23%) receiving a single drug and in 37 of the 72 (51%) receiving combined treatment. All the anti-inflammatory drugs caused gastric damage, the greatest offender being aspirin (13 out of 26 patients) and the least sulindac and diflunisal (two out of 19 (11%) and two out of 20 (10%) patients respectively). Corticosteroids caused gastric damage in only three out of 21 patients (14%), a lower incidence than expected.The indiscriminate prescribing of anti-inflammatory drugs to patients with OA is to be deplored. A lack of correlation between the patients' subjective complaints of gastric discomfort and the gastroscopic findings emphasises the unreliability of patients' complaints and the importance of gastroscopy in assessing gastric tolerance. It was not possible to assess minimal prescribing doses or minimum periods of treatment below which gastric damage may be guaranteed not to occur.

Epidemiological evaluation of rare side-effects of mild analgesics

1 Major adverse reactions to mild analgesics, unless these drugs are abused or taken in high doses, are believed to be rare. 2 However, because of the massive and universal use of these drugs, quantitative measurement of the risk involved is imperative. At present, contradictory regulatory decisions about the use of mild analgesics are based on circumstantial evidence. 3 It is only by the conduct of epidemiological studies that data leading to decisions based on scientifically sound judgments may be obtained.

Acute upper-gastrointestinal hemorrhage. New observations on an old problem

In a two-year period, 289 patients with acute upper-gastrointestinal hemorrhage were evaluated. The site of hemorrhage was proven by endoscopy in more than 90% of cases. The frequency of any particular bleeding site was characterized for several subgroups and was found to correlate with: (1) the severity of the bleeding episode; (2) the iatrotropic stimulus of hemorrhage, and (3) the history of ethanol consumption. No difference was found in the frequency of ulcer and acute mucosal lesions as sites of hemorrhage between patients who consumed aspirin and those who did not. A history of symptoms of peptic ulcer correlated with the presence of an ulcer as the bleeding site. It is possible that failure to identify important patient subgroups may be partially responsible for the disagreement between previous reports.

Drug consumption before perforation of peptic ulcer

In a retrospective study of 195 patients with a perforated peptic ulcer 18 per cent of the patients had taken aspirin, phenylbutazone or corticosteroids during the period before the perforation. In a controlled prospective trial, 18 of 22 patients (82 per cent) had taken drugs known to be potentially harmful to the stomach. Aspirin was the drug mainly used. Thirteen of 22 patients had taken the drugs within 12 hours of the perforation, usually because of symptoms not related to the gastro-intestinal tract. Drug consumption and perforation of pre-pyloric ulcers were most closely associated; the latter applies particularly to female patients, who either had only a short history of upper gastro-intestinal dyspepsia or were asymptomatic.

Upper gastrointestinal haemorrhage in hepatic cirrhosis: causes and relation to hepatic failure and stress

Emergency fibroscopy revealed bleeding lesions in 84 cirrhotic patients. In patients with moderate or no hepatic failure, the commonest actively bleeding sources were oesophagogastric varices and acute mucosal ulcers associated with the ingestion of anti-inflammatory drugs. In patients with severe hepatic failure, acute mucosal ulcers unrelated to drugs predominated and there was evidence that these were stress-induced erosions.

Drugs and gastric damage

The effects of aspirin, salicylate formulations and substitutes, smoking (nicotine), indomethacin, corticosteroids, phenylbutazone, ethanol, caffeine and reserpine on the gastric mucosa are discussed. The damaging effects of the drugs are considered in terms of the gastric mucosal barrier, gastric erosions, microbleeding and haematemesis and melaena and finally whether they cause peptic ulcer. There is suggestive evidence that unbuffered aspirin is a cause of haematemesis and melaena and of gastric ulcer but the incidence rates for hospital admission are low, being 10 to 15 per 100,000 heavy users per year. Aspirin in solution as acetylsalicylate buffered to maintain a neutral pH protects against gastric damage. Newer aspirin substitutes (mefenamic acid, fenoprofen, naproxen, tolmetin and ibuprofen) appear to cause less faecal blood loss than aspirin but their long-term effects have not been fully evaluated. Smoking is definitely associated with peptic ucler but the mechanism is unknown. Corticosteroids are probably not ulcerogenic despite clinical bias that they are. Indomethacin and phenylbutazone may be ulcerogenic but there is insufficient evidence to make firm judgements. Ethanol, caffeine and reserpine, on available evidence, are probably not ulcerogenic.

A synergistic interaction between aspirin, or other non-steroidal anti-inflammatory drugs, and stress which produces severe gastric mucosal damage in rats and pigs

A synergistic interaction was observed in the development of damage to the gastric mucosa of rats following the administration of a single oral dose of 50 or 200 mg/kg body weight aspirin and exposure to brief periods of cold or restraint stress. Under the experimental conditions employed, the stressed (control) animals did not develop any visible signs of damage while the rats given only aspirin developed typical small erosions. However, the animals given aspirin and simultaneously exposed to stress developed a large number of deep ulcers and massive haemorrhage. Similar results were obtained in rats given a variety of non-steroidal anti-inflammatory drugs, but not with dextropropoxyphene -- an analgesic devoid of ulcerogenic activity. In pigs, the chronic administration of aspirin and exposure to restraint stress resulted in the formation of deep crater-like ulcers. Only small focal lesions were found in the pigs given aspirin alone and no mucosal damage was evident in the pigs exposed only to stress. It appears that the aspirin plus stress synergism may be the basis for the formation of chronic gastric ulcers in humans.

Effect of naproxen on gastrointestinal microbleeding following acetylsalicylate medication

This study was undertaken to determine if substitution of naproxen for ASA does influence salicylate-induced gastrointestinal bleeding. Twelve normal volunteers were selected and given increasing doses of salicylate until guaiac tests were consistently positive. Autologous labeling of their red blood cells with 51-Cr was used to quantitate the microbleeding. After two weeks on ASA, six subjects were double blindly switched to naproxen and six to placebo for another two weeks of observation. Two-way analysis of variance on the raw data shows a significant treatment effect associated with a significant interaction in both groups. Final analysis on a logarithmic scale permits orthogonal contrasts to be accurately made without any significant remaining interaction. It is concluded that substitution of naproxen for ASA at a dose of 500 mg daily is accompanied by a rapid reduction of microbleeding to "normal" levels.

The management of upper gastro-intestinal tract haemorrhage

Two hundred successive patients with upper gastro-intestinal tract haemorrhage were admitted to a surgical unit for management. One hundred and thirty-five patients (67.5 per cent) had a chronic peptic ulcer, 33 patients (16.5 per cent) had acute lesions (either an erosive gastritis or an acute gastric ulcer), and 32 patients (16 per cent) were a mixture of other diagnoses, of which 13 (6.5 per cent) were simple conditions but 19 (9.5 per cent) were conditions with a bad prognosis, e.g., carcinoma of the stomach, oesophageal varices, aortic aneurysm. Surgery was undertaken for massive, continuing, or recurrent bleeding and was as ‘conservative’ as thought possible. In duodenal ulcer this consisted of suture of the ulcer with vagotomy and pyloroplasty, and suture of the ulcer with vagotomy where possible in cases of anastomotic ulcer. In gastric ulcer only those less than 2 cm. in diameter were treated by suture with vagotomy and pyloroplasty. Ulcers greater than 2 cm. in size requiring surgery were treated by gastrectomy.

In the 181 patients whose underlying condition had a good prognosis there were 7 deaths (4 per cent). In this group 81 operations were carried out; 61 were ‘conservative’ operations for peptic ulcer, 2 were for repair of a hiatus hernia, and there were 18 gastrectomies, usually for a large gastric ulcer. There were 2 deaths among the operated patients; 1 after gastrectomy and 1 after a ‘conservative’ operation. There were 5 deaths among the 100 patients in the group which was treated non-operatively. There were 8 deaths among the 19 patients with underlying conditions of grave prognosis.

The case for the admission of patients with upper gastro-intestinal tract bleeding to a surgical unit is fully discussed and it is advocated together with a selective policy for operation. Where operation is necessary this should be as conservative as possible for bleeding duodenal ulcer, chronic gastric ulcer less than 2 cm. in size (ulcers of larger size may well respond but the method was not assessed for such ulcers), solitary acute gastric ulcer, and anastomotic ulcer. Gastric resection should be retained for the few patients with diffuse erosive gastritis requiring surgery and possibly for patients with a very large chronic peptic ulcer.

Aspirin ingestion and perforated peptic ulcer

The results of a prospective inquiry into the aspirin taking habits of a consecutive series of 118 patients admitted to a large general hospital with acute perforation of peptic ulcer are presented. The series shows considerable increase in the proportion of females to males and of ulcers of the stomach compared to pyloro-duodenal perforations in contrast to British experience. Forty-five per cent of males and 75% of females were accustomed to taking at least two doses of an aspirin preparation weekly and most of the women took at least two doses daily. There was a highly significant association of heavy aspirin intake with ulcers of the stomach. The data support the theory that aspirin abuse is a cause of chronic gastric ulcer. It also supports the hypothesis that aspirin is the environmental factor responsible for the epidemic of gastric ulcers in middle-aged women in eastern Australia.

Aspirin and alcohol in gastrointestinal haemorrhage

The intake of aspirin, of alcohol, and of a combination of both, among 817 patients admitted for gastrointestinal haemorrhage is reported. The incidence of ingestion in six diagnostic groups is compared with that in two control groups. Analysis confirms that there is a markedly significant association between overt haemorrhage and the ingestion of aspirin, but this was not shown for alcohol taken alone: the combination of aspirin and alcohol showed a highly significant synergistic effect.