Evaluation of the paradigm

From the foregoing review of the existing literature, it is evident that dyspepsia is a common problem worldwide^{1, 4, 5} accounting for up to 2-5% of cases seen in Family practice in the United States.²²

In Nigeria, dyspepsia has also been estimated to affect about 40 % of adult patients seen in hospital settings.^{19, 57}

The term “dyspepsia” has been variously defined to either include or exclude certain symptoms in the definition. Currently, the Rome consensus working party definition is the most widely accepted ⁴ but the Canadian dyspepsia (Candys) groups’ definition appears more acceptable in primary care; taking into cognisance the usual symptoms that primary care physicians generally consider to be part of the dyspepsia symptom complex the Candys group includes “heartburn”

and “reflux symptoms” in its definition of dyspepsia. ^{2, 25} The Rome consensus working group on the other hand, considers heartburn and reflux to be more specific for Gastro-oesophageal reflux disease.^{3, 4} For the purpose of the present study however, the Candys definition was adopted as the study was conducted in primary care settings.

An interplay of gastro-intestinal factors which include dysmotility, visceral hypersensitivity, gastric motor dysfunction, gastric acid secretion and psychological factors among others are believed to be involved in the pathophysiology of dyspepsia.^{1, 5, 13}

However, it has been estimated, that in up to 60% of patients presenting with un-investigated dyspepsia in primary care there is no identifiable cause after investigation.^{5, 10, 11} Such patients

38

are described as having “functional” as opposed to “organic” dyspepsia for which there is an underlying cause.

While the role of H. pylori infection in the aetio-pathogenesis of Peptic ulcer disease and Gastric cancer is well known, the exact role of the organism in the aetiology of functional dyspepsia is yet to be ascertained.^{4, 5, 6} H. pylori status is therefore unlikely to affect therapeutic outcome in functional dyspepsia. Large trials have failed to identify any difference in therapeutic outcome in H. pylori positive versus negative patients.⁴ A systematic review had also failed demonstrate an improvement in symptoms after H. pylori eradication in functional dyspeptics.^{6, 9, 34}

A few studies have however shown, that H. pylori eradication was associated with better symptom relief compared to conventional therapy without eradication in patients presenting in primary care with un- investigated dyspepsia.⁴ More data is however needed before definite conclusions could be made.

In primary care, the diagnosis of dyspepsia is based on patients’ symptoms and in line with standard guidelines for clinical diagnosis. The National Institute for Clinical Excellence (NICE) and the American College of Physicians had proposed guidelines for the diagnosis and management of un-investigated dyspepsia in primary care.^{4, 7}

The aim of management of dyspepsia in primary care is to relieve symptoms and improve quality of life without unnecessary invasive investigations. The NICE guideline for primary care management of dyspepsia 2005, states; “in the management of dyspepsia in primary care, routine endoscopic investigation of patients of any age presenting with dyspepsia and without alarm signs is unnecessary”⁷

39

Current primary care practice guidelines therefore, recommend an empiric approach to the management of patients with un-investigated upper gastro-intestinal symptoms including epigastric pain or burning that is thought to be acid related.^{7, 46}

Empiric anti-secretory therapy which is widely applied in practice was first proposed by the American College of Physicians in 1985.⁴

The American guideline recommends the “test and treat” strategy for younger patients (less than 55 years of age) presenting with dyspepsia without alarm features in areas with moderate to high (≥ 10%) prevalence of H. pylori infection.^{4, 34}

The “test and treat” strategy is now regarded as the gold standard in the management of dyspepsia in areas with high prevalence of H. pylori infection. ^{4, 5} Unfortunately the “test and treat”is still not a feasible strategy in most primary care settings in developing countries like Nigeria due to non availability of standard non-invasive point of care tests for H. pylori infection.⁸

This limitation has led to the development of the “empirical triple therapy” being widely practiced in resource poor settings with high prevalence of H. pylori infection in the management of patients with un-investigated dyspepsia.

While the use of empiric triple therapy in the management of un-investigated dyspepsia in primary care may be appropriate in resource poor settings in view of the high prevalence of H.

pylori infection in such areas, the rampant and irrational use of antibiotic medications

40

associated with it, has resulted in additional costs to the patient and increasing risk for developing drug allergies, super-infection and antibiotic resistance.⁵

A number of randomized controlled clinical trials have reported benefits from the use of anti-secretory agents in relieving symptoms of un-investigated dyspepsia in primary care settings.⁴

The two groups of anti-secretory agents used in primary care are the H2-receptor antagonists (H2-RAs) and the Proton Pump Inhibitors (PPIs). ^{2, 18}

The proton pump inhibitors (PPIs) have been shown by a number of studies, to be superior to H2-receptor antagonists (H2RAs)in the amelioration of dyspeptic symptoms15, 22, 54, 56 while a few studies went in favour of the H2-RAs. ^{2, 56}

Ranitidine a second generation H2-receptor antagonist, is readily available, quite affordable, relatively safe and commonly prescribed in primary care; it is well tolerated by most patients at the usual twice daily therapeutic dose.¹⁸

Omeprazole, a proton pump inhibitor is also available and has been shown to be safe, well tolerated and efficacious in the amelioration of dyspeptic pain among Nigerians. ⁵³

This study compared the efficacies of Ranitidine and Omeprazole, two commonly prescribed anti- secretory agents for the treatment of un-investigated dyspepsia in primary care.

41

CHAPTER THREE

METHODOLOGY