Survey of prescriptions for peptic ulcer drugs (ACT class AOB2) in Iceland

First evidence of a possible association between gastric acid suppression during pregnancy and childhood asthma: a population-based register study

BACKGROUND

Recent data in mice suggest that acid suppression during pregnancy yields offspring with type 2 T helper-dominant immunity, suggesting a predisposition for allergy.

OBJECTIVE

To determine the association of in utero exposure to acid-suppressive medications and the subsequent development of allergic diseases in children.

METHODS

We studied a population-based observational cohort formed by linking data from three Swedish national healthcare registers: the Medical Birth Register, the Hospital Discharge Register, and the Swedish Prescribed Drug Register. Main outcome measures included a hospital discharge diagnosis of an allergic disease or prescription for asthma medications, epinephrine auto-injectors, antihistamines or steroid ointments in children. Data were analysed using the Mantel-Haenszel procedure.

RESULTS

Twenty-nine thousand four hundred and ninety (5.03%) children had a discharge diagnosis of allergy or prescriptions for allergy medications. Five thousand six hundred and forty-five (0.96%) children had been exposed to acid suppression therapy during pregnancy; of these, 405 (0.07%) were treated for allergic diseases. Exposure to acid-suppressive medications in utero was associated with an increased odds ratio (OR) for developing allergy (OR 1.43, 95% confidence interval (95% CI) 1.29-1.59). We observed this association irrespective of the type of drug, time of exposure during pregnancy, and maternal history of allergy. The use of maternal acid-suppressive medication was associated with an increased OR for the development of childhood asthma (3.7% in the population at large vs. 5.6% in exposed children, OR 1.51, 95% CI 1.35-1.69), but not for other allergic diseases.

CONCLUSION

These data provide first evidence of a significant association between in utero exposure to acid-suppressive drugs and the risk of developing childhood asthma.

Use of anti-secretory medication: a population-based cohort study

BACKGROUND

Total use of anti-secretory medication (H2 blockers and proton pump inhibitors) is increasing rapidly, but knowledge of factors related to the increasing use is sparse.

AIM

To describe development in the use of anti-secretory medication between 1993 and 2002 at a population level.

METHODS

We extracted data on use of anti-secretory medication (H2-blockers and proton pump inhibitors) and ulcerogenic drugs, demographic data, and data on gastroscopy and endoscopically verified oesophagitis and peptic ulcer diagnoses, from three large population-based databases covering the County of Funen, Denmark 1990-2002 (population 470,000).

RESULTS

Between 1993 and 2002 incidence of first time users was stable at 16.7/1000 persons/year. Total amount of consumed anti-secretory medication increased from 10.5 DDD/1000 persons/day to 25.2 DDD/1000 persons/day. Ninety per cent of the increase was related to long-term use of anti-secretory medication (> or = 180 DDD/patient/year). In 1993 21% of the anti-secretory medication was used by patients with oesophagitis, this increased to 28% in 2002. The proportion of medication used by peptic ulcer patients decreased from 29% in 1993 to 19% in 2002.

CONCLUSIONS

Total use of anti-secretory medication increased as a result of more extensive long-term use, and most of the medication was used by patients without diagnosed peptic ulcer or oesophagitis.

Prevalence of anti-ulcer drug use in a Chinese cohort

AIM: To estimate the age-specific prevalence of anti-ulcer drug use and to calculate the usage of different anti-ulcer drugs over 5 years within the universal health insurance program in Taiwan area.

METHODS: The National Health Insurance Research Database in Taipei supplied the cohort data sets of 200000 people. The ambulatory and inpatient claims of the cohort from 1997 to 2001 were analyzed. The anti-ulcer drugs included all drug items of the group A02B (drugs for treatment of peptic ulcer) in the Anatomical Therapeutic Chemical classification system (version 2000). The amount of drug usage was measured in unit of defined daily dose.

RESULTS: Among the totally 13034393 visits with 56672631 ambulatory prescription items, there were 398150 (0.7%) prescribed items of anti-ulcer drugs in 378855 (2.9%) visits. Among the 107649 admissions with 5762312 inpatient prescription items, there were 24598 (0.4%) prescribed items of anti-ulcer drugs in 11548 (10.7%) admissions. The annual prevalence of anti-ulcer drug use was 9.6% in 1997, 11.6% in 1998, 15.4% in 1999, 14.5% in 2000, and 15.9% in 2001 respectively. The 5-year prevalence was 36.1%. The age-specific prevalence among the people younger than 20 years was 9.2% in 2001 and 23.7% during the 5-year period. Cimetidine not only was the most popular ingredient among anti-ulcer drugs (57634 cimetidine users in 70729 all anti-ulcer drug users during the 5-year period) but also had the largest prescribed amount (42.3% of DDDs for all anti-ulcer drug users during the 5-year period). The annually prescribed amount of anti-ulcer drugs had grown from 4.9 DDDs/1000 inhabitants/day in 1997 to 7.5 in 2001. This increase was largely attributed to H₂-receptor antagonists and the expanding number of users.

CONCLUSION: Prescribing of anti-ulcer drugs is indeed popular among the Chinese population in Taiwan area. The disproportionate use of anti-ulcer drugs by children demands further investigation.

Treatment of acid-related diseases in the elderly with emphasis on the use of proton pump inhibitors

Proton pump inhibitors (PPIs) have revolutionised the treatment of acid-related disorders, and they have also made it possible to define the spectrum of acid inhibition required for optimal treatment in each disorder. Five PPIs are now available: the older drugs, omeprazole, lansoprazole and pantoprazole, and the two newest, rabeprazole and esomeprazole. These agents have predominantly been developed in the younger adult population, and data for the elderly population are limited. Subtle differences have emerged between the old and the new PPIs in their pharmacokinetic, pharmacodynamic and efficacy profiles. The degree of clinical relevance of these differences in the adult population is in question. However, according to this review, based on the available data for the elderly and by inference from the adult population, the differences are highly relevant in the elderly population. Studies of the pharmacokinetics of older PPIs demonstrated considerable variation in drug clearance that was reflected in a wide range of efficacy related to acid suppression with standard dosages. The newer PPIs offer several advantages over older agents, particularly in terms of rapid, profound and consistent acid inhibition. Consistent acid inhibition is particularly important in the elderly since clinical response is often difficult to judge in this patient group. An individual's cytochrome P450 (CYP) 2C19 genotype predicts the degree of acid suppression and consequently the clinical efficacy of the PPIs. The older PPIs are predominantly metabolised by CYP2C19, with this being of more importance for omeprazole and lansoprazole than pantoprazole. The hepatic metabolism of rabeprazole is predominantly by nonenzymatic reactions and minimally by CYP-mediated reactions, which therefore confers an advantage over older PPIs in that genetic polymorphisms for CYP2C19 do not significantly influence rabeprazole clearance, clinical efficacy or potential for drug interactions. The metabolism of esomeprazole involves CYP2C19 but to a lesser extent than its predecessor omeprazole. Furthermore, esomeprazole has a more rapid onset of action and less variation in clearance rates than omeprazole. Drug clearance decreases with age independently of CYP2C19 status, exaggerating some of the differences between the PPIs and increasing the risk of drug interactions.

Current indications for acid suppressants in dyspepsia

Anti-secretory drug use is common in patients with uninvestigated and functional dyspepsia, but the value of such agents has been controversial. Four large studies have evaluated the symptomatic outcome after a short course of acid inhibition in patients with uninvestigated dyspepsia presenting in primary care. All of these studies demonstrated a superior symptom response to proton pump inhibitor therapy compared with placebo and acid-alginates or H(2)-receptor antagonists. In patients with documented functional dyspepsia, 17 parallel group trials have evaluated an H(2)-receptor antagonist against placebo, with mixed results. A recent Cochrane review based on eight controlled trials concluded that there was a significant benefit of H(2)-blockers over placebo with a relative risk reduction of 30%, but as gastro-oesophageal reflux disease was not excluded, the conclusions are questionable. Six controlled studies have compared symptom relief after a short course of proton pump inhibitor therapy compared with placebo. Overall, there does appear to be a therapeutic gain with proton pump inhibitors over placebo, although how much of this is explained by undiagnosed gastro-oesophageal reflux disease remains unclear. There is conflicting evidence on the value of symptom subgrouping as a predictor of response to acid suppression. Overall, there is little convincing evidence that Helicobacter pylori infection influences the therapeutic outcome of acid-suppressant therapy. In conclusion, there appears to be a subgroup of patients with functional dyspepsia who will respond to acid suppression over and above placebo, but further work is required to characterize these responders.

Overuse of proton pump inhibitors

BACKGROUND

There have been concerns raised about the potential adverse effects of proton pump inhibitors, especially with long-term use. In particular, their potent action can suppress the features and delay the diagnosis of gastric cancer, while prolonged exposure may hasten the development of gastric carcinoids.

AIM

To examine the use of proton pump inhibitors in patients at the major teaching hospital in Tasmania, Australia, principally to determine the appropriateness of the therapy according to published guidelines.

METHODS

A retrospective review of the medical records of all patients prescribed any of the proton pump inhibitors at the hospital over a 7-month period, was performed. An extensive range of demographic and clinical variables was recorded for each patient. The patients were also asked a series of questions during their hospitalization to extract some of the relevant information - in particular, if and when they had undergone endoscopy.

RESULTS

The 200 patients (52% males) had a mean age of 69 +/- 16.4 years. The most common indications for using proton pump inhibitors were acute gastrointestinal bleeding (20.9%), severe refractory ulcerating oesophagitis (17.3%), mild/moderate oesophageal reflux (17.3%) and refractory peptic ulcer (11.7%). A large number of patients were using a proton pump inhibitor for 'other' indications (39.6%). The prescribing of proton pump inhibitors satisfied the approved indications, as outlined in the Australian Schedule of Pharmaceutical Benefits, in only 37.1% of cases. Endoscopy had been performed in 54.1% of patients prior to commencing therapy with a proton pump inhibitor and within the next 7 days in another 12.8% of patients. Only 59% of patients had previously been treated with an H2-receptor antagonist before commencing therapy with a proton pump inhibitor. Even worse, only 58.5% of patients had used an H2-receptor antagonist before a proton pump inhibitor for mild/moderate oesophagitis. The median duration of proton pump inhibitor therapy for patients admitted to the hospital and already receiving one of the drugs was 450 days. Over half of the patients were being concurrently treated with other drugs which are known to cause or exacerbate gastro-oesophageal disease, and 18% were smokers.

CONCLUSION

Whereas the proton pump inhibitors are undoubtedly effective agents, studies of their prescribing in practice consistently suggest over-use prior to endoscopy, use in patients who do not fit the approved criteria, and prescribing for indications in which 'less powerful' agents should have been sufficiently effective for the patient's symptoms. This poses economic and safety concerns, particularly in light of the suggestion that these drugs could delay the diagnosis of gastric cancer.

Antacid (A02A) and antiulcer (A02B) drug prescription patterns: predicting factors, dosage and treatment duration

BACKGROUND

A study is made of the pharmaco-epidemiology of antacid (ATC class A02A) and antiulcer (A02B) drug prescriptions during the year 1992.

METHODS

Prescription data were extracted from 1941 case histories of patients over 15 years old from four health care centers in the Valencian Community (Spain). Dosage and treatment duration were evaluated, along with the way in which morbidity, self-evaluated health, the demographic pattern and life-style characteristics influence drug prescription.

RESULTS

The proportion of drug prescriptions increased with age in both sexes (p < 0.01). Drug use depended mainly on chronic diseases. In prescribing antacids, the most influential diagnosis was gastritis (ICD 534, OR: 157), followed by duodenal ulcer (ICD 532, OR: 152) and gastric ulcer (ICD 531, OR: 122), other gastrointestinal disorders (ICD 66, OR: 54) and undefined diagnoses (OR: 15). In the prescription of antiulcer drugs, the most influential diagnoses were gastric and duodenal ulcer (OR: 380 and 342, respectively), and a significant relation was observed with the diagnosis of osteomuscular diseases (OR: 6). Lifestyle and demographic pattern were of marginal importance. The estimated duration of treatment was 85 days. No significant differences were observed in either treatment duration or administered doses of almagate, ranitidine and omeprazole with respect to sex, age or diagnosis.

CONCLUSIONS

Prolonged treatment is common for acid suppression. The widespread use of peptic ulcer drugs is mostly due to excessive prescription for non-ulcer dyspepsia. At the same time, many patients consume these drugs on a long-term basis in the absence of a clear diagnosis. This observation supports the need for appropriate diagnostic and prescription protocols to secure increased economical savings and management results.

Ranitidine effectively relieves symptoms in a subset of patients with functional dyspepsia

BACKGROUND

Acid secretion inhibitors are of dubious value to most patients with functional dyspepsia but might be effective in a subset. The aims of the trial were to compare the effect of ranitidine with that of placebo in selected subsets of patients.

METHODS

Two hundred and twenty-six patients with functional dyspepsia were included in a double-blind multi-crossover (MCO) trial. After 6 weeks an effect score (Xs) with a range of 0-5 was calculated. They were then stratified in accordance with their score and randomized to 4 weeks' double-blind treatment with ranitidine or placebo. Overall symptoms were scored on a 100-mm visual analogue scale, and the change in score (measured in millimetres) was the primary effect measure.

RESULTS

Two hundred and six patients completed the study. The effect of ranitidine and placebo in the 'responders' (76 patients with Xs of 4-5 after the MCO period) was 28 mm and 5 mm, respectively (P < 0.001), and in all patients 19 mm and 12 mm, respectively (P < 0.03). No effect was seen in 'nonresponders' (130 patients with Xs of 0-3 after the MCO period). The clinical improvement, as judged by the patients given ranitidine during the last 4-week period was statistically significantly different in favour of responders compared with nonresponders. We were unable to characterize the responders on the basis of demographics, symptoms, and signs.

CONCLUSIONS

Ranitidine has a good and clinically significant effect in a subset of patients with functional dyspepsia.

Determinants of initiation and suboptimal use of anti-ulcer medication: a study of the Quebec older population

OBJECTIVES

To describe the use of anti-ulcer medication in the Quebec older population; to examine determinants of initiation, suboptimal use, and switches between products.

DESIGN

Population-based retrospective cohort study.

SETTING

Universal health program for older adults in Quebec.

PARTICIPANTS

5000 users and 5000 non-users of anti-ulcer medications were selected randomly. Use was defined as the presence in the 1991 prescription database of an anti-ulcer prescription. Among users, 1697 (34%) were new users and were considered as the exposure group. Subjects were followed for 365 days after inclusion.

MEASUREMENTS

Measured were patient's age, gender, prescribed duration of anti-ulcer medication, concomitant medications, and gastrointestinal diagnostic procedures.

RESULTS

A total of 17% of new users had unusually short courses; 18% were long-term users. There was no difference in duration for omeprazole compared with other anti-ulcer medications. First-time use of NSAIDs was the strongest predictor of initiation of anti-ulcer medication (odds ratio = 3.21; 95% CI, 2.66-3.88). Twenty-six percent of users switched brands. Only 9.5% of new users underwent a diagnostic procedure before initiation of therapy, and 49% of long-term users ever underwent such procedure.

CONCLUSION

Despite a relatively homogeneous recommended duration of therapy, patterns of use of anti-ulcer medication among older people are highly variable, and treatment is often not accompanied by a diagnostic procedure.