Title: Upper GI Tract Problems

Key words: Digestive system, indigestion, heartburn, acid indigestion, flatulence, bloating, gastritis, self-medication, alginates, antacids, H2- antagonists, reflux, hiatus hernia, peptic ulcer, bowel cancer,

Date: Aug 2000

Category: 8. The Gut

Type: Article

Author: DJE Candlish

 

Upper GI Tract Problems

 

Introduction

A high proportion of customers who seek advice on self-medication from their pharmacy do so for minor stomach complaints, such as heartburn or acid-indigestion. General discomfort in the upper gastrointestinal tract, accompanied by stomach pain, flatulence, bloating or heartburn, is very common. In fact, almost everyone is subject at some time or another to the after-effects of over-indulgence, but many people suffer repeated or troublesome symptoms even after the blandest of foods.

"Indigestion" is a term encompassing a wide range of symptoms and it can mean different things to different people. The pharmacist and pharmacy staff can help customers choose the optimum treatment for their particular symptoms. They are also ideally placed to advise on lifestyle changes and offer self-help measures which can benefit those who suffer repeatedly from acid-related problems. Since other more serious disorders can have similar symptoms to those seen in heartburn or indigestion, the pharmacist also has a key role in recommending referral to a GP whenever an underlying problem is suspected.

This article puts the acid-related stomach problems into context and covers the available OTC treatments in this market, including the H2-antagonists.

 

Contents

The digestive system

Review of structure and function

The passage of food through the upper gastrointestinal tract

Stomach acid

Problems of the upper gastrointestinal tract

Heartburn and indigestion

Definitions

Symptoms of heartburn and indigestion

What causes indigestion and heartburn?

Differential diagnosis of heartburn and indigestion

Management of heartburn and indigestion in the pharmacy

When to refer ?

Self-help advice

Treatment options

Category profiles

 

The digestive system

Review of structure and function

The body’s digestive system consists of the gastrointestinal tract (also known as the GI tract, gut, digestive tract or alimentary canal) together with associated organs (e.g. salivary glands, liver, gall bladder, pancreas).

The gastrointestinal tract consists of the mouth, pharynx (throat), oesophagus (gullet), stomach, small intestine, colon, rectum and anus. Structurally, the tract is a tube composed of four basic layers, each highly specialised with its own function. From the outer to the inner surfaces of the tube, these layers are:

The part of the tract commonly referred to as the upper gastrointestinal tract consists of the portion above and including the stomach.

As a whole, the system is responsible for processing food, extracting nutrients and introducing them into the blood-stream so they can be used by the body. The system also works to remove indigestible waste residues from the body.

 

The four main functions of the system are:

The passage of food through the upper gastrointestinal tract

Ingestion and the initial stages of digestion are the processes which take place in the upper gastrointestinal tract.

The stomach itself is protected against damage from the highly acidic gastric juice by a thick jelly-like protective mucus layer, which is rich in bicarbonate.

Stomach acid

A number of disorders associated with the upper gastrointestinal tract occur due to an excess of stomach acid or to stomach acid being present in the wrong place in the gastrointestinal tract. For this reason it is important to discuss stomach acid in more detail here.

Stomach or gastric acid is hydrochloric acid, produced and secreted by specialised cells present in the gastric glands located in the inner mucosal lining of the stomach. These oxyntic or acid secreting cells are called the parietal cells. The acid they produce makes the stomach contents highly acidic.

Stomach acid has two important roles:

Secretion of stomach acid is stimulated by the sight, smell and taste of food and by the presence of food in the stomach. Control mechanisms for acid production and secretion are complex and inter-related, involving nerve pathways, the hormone gastrin, and the body chemical histamine. Histamine can act directly on parietal cells to increase both the rate and volume of acid secretion; this effect is mediated by histamine binding to specific histamine (H2)-receptors present on parietal cells.

Problems of the upper gastrointestinal tract

Heartburn and Indigestion

Stomach acid is important in the process of digestion, but excess stomach acid or acid which gets into the wrong place in the gastrointestinal tract can result in a number of common acid-related problems. One such problem is reflux, which results in the condition known as heartburn. Another common problem associated with excess stomach acid is indigestion, otherwise known as dyspepsia.

Of the many and varied disorders associated with the upper gastrointestinal tract, heartburn and dyspepsia are common ailments recognised as indications suitable for self-medication. These acid-related problems affect around 20-40% of the adult population at some time in their lives. Both problems tend to be more common in men and their occurrence increases with age, being highest in the over 55’s.

 

Hiatus hernia

In this condition, the upper part of the stomach protrudes through the diaphragm into the chest cavity so the LOS may not function correctly. This can allow acid to pass back (reflux) into the oesophagus from the stomach. As a result, hiatus hernia frequently causes heartburn. Surgery may be required to rectify a hiatus hernia.

Gastritis

Gastritis is a chronic inflammation of the gastric lining, causing severe discomfort. It may be caused by reflux of the duodenal contents back into the stomach or to prolonged and excessive intake of alcohol, aspirin or hot, spicy foods, but the evidence for this is uncertain. Infection with a bacterium, Campylobacter or Helicobacter pyloris, is now being investigated as a more likely cause.

 

Peptic ulcers

A peptic ulcer is an erosion of the mucosal lining of the stomach or duodenum, once thought to be caused solely by over-production of acid and digestive juices. In recent years, however, convincing evidence has been found for the involvement of the bacterium, Helicobacter pylori, in the development of ulcers in both the stomach and duodenum. Treatment with a suitable antibiotic has proved effective in dealing with these ulcers.

The main symptoms, causes, influencing factors and aspects of diagnosis of these common problems is discussed below.

 

Definitions

 

What causes indigestion and heartburn ?

Simply put, excess stomach acid can result in indigestion while acid in the wrong place in the gastrointestinal tract (i.e. in the oesophagus) can result in heartburn.

Excess stomach acid

The absolute amount of acid in the stomach is affected by a number of factors; some of these are genetic (e.g. the inherent rate of acid secretion, the rate at which the stomach empties its contents etc.) and some are imposed by lifestyle or diet. The external factors listed below can induce acid-related stomach problems.

External factors affecting the levels of stomach acid

Lifestyle Factors

Smoking

Obesity

Stress

Dietary Factors

("trigger" foods)

Hot, spicy foods

Fatty foods

Caffeine ( in coffee, tea, cola)

Alcohol

Reflux

Reflux is the upward or backward flow of the acidic stomach contents into the oesophagus. The two main factors which contribute to reflux are:

Factors which relax the LOS

Dietary Factors
(often called "trigger" foods

Fatty foods, chocolate, peppermint, onions, alcohol

Lifestyle Factors

Smoking

Hormonal Factors

High levels of female hormones (as occur during pregnancy)

Other Factors

Certain drugs (including some treatments for asthma, anxiety, heart disease)

When reflux occurs, the presence of the acidic stomach contents in the oesophagus results in the painful burning sensation of heartburn. The pain is due to the effects of the irritant hydrochloric acid on sensitive nerve endings in the oesophagus. The oesophageal lining can be easily damaged by acid because it has a thinner, less protective mucus layer than the stomach. In the stomach, the mucosa secretes bicarbonate ions which neutralise acid, giving the gastric lining greater protection against acid damage.

Symptoms of heartburn and indigestion

Heartburn symptoms include:

Heartburn commonly occurs at night when the sufferer is lying down and can be brought on by stooping or bending. Often, heartburn is accompanied by other symptoms such as nausea or bloating. Heartburn is itself recognised as one symptom of dyspepsia (indigestion).

Dyspepsia symptoms are often described by the sufferer as "upset stomach" or "acid stomach". The condition encompasses a whole range of symptoms relating to excess acid in the upper gastrointestinal tract. Sufferers may complain of all of the following or they may simply experience one or two of these symptoms:

These symptoms can vary considerably in severity and quantity and can be very distressing for a sufferer, significantly reducing his or her quality of life. The pain associated with indigestion is often severe, felt as a "stabbing" or "burning" pain; it can be frightening because it may be confused with the chest pain of a heart attack.

 

Differential diagnosis of heartburn and indigestion

Differential diagnosis is important because the pain and other symptoms associated with heartburn or indigestion should always be distinguished from similar symptoms due to other more serious medical conditions. A small proportion of people complaining of heartburn, stomach pains or other symptoms associated with the upper gastrointestinal tract may be suffering from one of the conditions described below, all of which require referral.

It is important to keep all this in context, since the vast majority of people suffering intermittent heartburn or indigestion-like symptoms will have no underlying disease, and can be helped in the Pharmacy with lifestyle and dietary advice and suitable over-the-counter treatments.

 

Self-Management of Heartburn and Indigestion

Heartburn and indigestion are common acid-related stomach problems. A combination of lifestyle advice with appropriate drug treatment can be an effective solution for many sufferers. There are a number treatment choices available from sources such as supermarkets (GSL), the Pharmacy (GSL and P) or on prescription from the doctor (POM). The way in which the products work, their effectiveness and their advantages and disadvantages in use also vary considerably.

 

When to see a Professional

Self-medication for acid-related stomach problems is common, but is not always the best course of action for everyone with symptoms related to the upper gastrointestinal tract. If the problems are persistent, you should consult a doctor or other healthcare professional for advice. You should certainly seek advice when your symptoms of heartburn or indigestion are:

* Certain OTC antacid/combination remedies (see below) can be recommended for heartburn associated with pregnancy. H2 antagonists should only be used on the advice of a doctor.

Professional advice is also required where additional symptoms develop, such as:

If you are taking any medication for your symptoms, it is particularly important to tell your healthcare professional, since it is possible that these medicines may actually be causing the upper gastrointestinal symptoms. Many drugs can cause gastrointestinal side effects, such as OTC painkillers containing aspirin or ibuprofen. These can irritate the stomach, resulting in dyspepsia-like symptoms. A wide range of prescription medicines e.g. antibiotics, can also cause stomach discomfort.

 

 

Self-help advice

The role of lifestyle and diet as contributing factors in heartburn and indigestion has been covered above. Understanding how such factors can cause or worsen acid-related stomach problems makes it easy to appreciate how avoidance of such factors will help prevent, or at least reduce, further attacks. By following the advice given below, sufferers can help themselves reduce unpleasant symptoms.

Treatment options

As well as self-help advice, many sufferers also need medicines to help manage their acid-related problems. Suitable medicines for these indications fall into the following categories:

A. Products which reduce stomach acidity

Since acid is the immediate cause of the pain and discomfort associated with heartburn and indigestion, symptom relief can be achieved by reducing the level of stomach acidity. The aggressive effects of stomach acid can be reduced by

Products which fall into this category include:

 

B. Products which affect gas in the gastrointestinal tract

Gas, or wind, in the stomach and upper part of the gastrointestinal tract plays a significant role in the generation of symptoms such as flatulence, bloating and discomfort. The effects of gas can be reduced by "defoaming" agents which break down or coalesce gas bubbles, enabling belching and clearing of the discomfort. Products which fall into this category include the antiflatulent agents (GSL).

C. Products which enhance movement of the gastrointestinal tract

Drugs in this category promote peristalsis and prevent inappropriate relaxation of the LOS, so reducing the frequency and duration of reflux episodes and increasing the movement of food through the gastrointestinal tract. These are prescription-only drugs and therefore more likely to be used in severe cases of reflux or dyspepsia or for patients who have failed to respond to acid-reducing treatments.

Examples of products in this category are dopamine antagonists and cisapride.

In summary, the antacids, alginates, antiflatulents and some H2-antagonists are all over-the-counter products for use in the treatment of heartburn, intermittent indigestion and symptoms related to excess stomach acidity. The proton pump inhibitors, motility enhancers and H2-antagonists (at higher doses) are currently prescription-only drugs, mostly with a wider range of indications. For example, H2-antagonists at prescription doses are used mainly for the treatment of severe oesophagitis due to reflux and in the treatment and prevention of stomach and duodenal ulcers.

 

Treatment profiles

Antacids

Antacids are alkaline substances and are the most commonly used self-medication for problems such as heartburn and indigestion. They are widely available from retail outlets and pharmacies. Formulated as tablets, chewable tablets or liquids, they work quickly by reacting with hydrochloric acid to neutralise excess stomach acidity. Antacids have a limited duration of action and repeat dosing is sometimes necessary.

Popular antacids contain varied combinations of aluminium hydroxide, magnesium oxide/hydroxide, magnesium trisilicate, magnesium carbonate, calcium carbonate and sodium bicarbonate.

Side effects with antacids are infrequent, usually short-lived and mild. They can be similar to the symptoms being treated e.g. stomach pain and belching, but nausea/vomiting, diarrhoea and constipation may also occur. More serious side effects can occasionally occur if large doses of antacids are frequently used. These include formation of kidney stones and disturbance of ionic (electrolyte) balance in the blood.

Antacids can interact with a number of other drugs which the sufferer may be taking at the same time. The result is usually a reduced or increased amount of the other drug in the body, leading either to lack of therapeutic effect or an increased risk of side effects. Examples of drugs with which antacids can interact are listed below.

Drug Class

Possible interactions

Antibiotics

tetracycline, rifampicin

Anticonvulsants

phenytoin

Antifungals

ketoconazole, itraconazole

Antimalarials

chloroquine

Antipsychotics

phenothiazines

Antirheumatics

penicillamine

Minerals

iron

Alginates (rafting agents)

Alginate products usually combine alginic acid or sodium alginate with antacids. On contact with the liquid stomach contents, the alginate and antacid form a gel which acts like a "raft", floating on top of the stomach contents. The raft effectively prevents reflux up into the oesophagus and even if reflux does occur, the gel forms a protective coating on the oesophageal mucosa helping to prevent acid-induced pain and damage. Because of this mode of action, alginates are of most benefit in heartburn and should be taken after eating.

However, the beneficial effects of alginates can be short-lived because the raft effect is lost:

Alginates are widely used, widely recommended products, available from pharmacies, in the form of tablets or liquids. In general, alginates are well tolerated. Any side effects which occur are often related to the antacid content of the product. Similarly, the potential for drug interactions is also similar to that for antacids alone. Preparations containing sodium alginate have a high sodium content and are best avoided by individuals on a low sodium diet (i.e. for high blood pressure or fluid retention problems).

 

Antiflatulents

Antiflatuent products contain a defoaming agent e.g. dimethicone or simethicone, often in combination with an antacid. The defoaming agent breaks down gas bubbles in the stomach, which helps to reduce wind, bloating and stomach discomfort. Their action renders these products most suitable for the relief of indigestion, particularly where flatulence/wind is a major symptom.

Side effects of antiflatulents are infrequent and, as with alginates, are generally related to the antacid content of combination products. The potential for drug interactions is again similar to that for antacids alone.

Defoaming agents should not be taken together with rafting agents, because the defoaming agent destroys the raft.

In addition to indications for use in heartburn and dyspepsia, several OTC simethicone/antacid combinations are also specifically indicated for use in the management of symptoms associated with hiatus hernia, oesophagitis, gastritis (stomach inflammation/acute discomfort) and peptic ulceration. These conditions have been discussed above as differential diagnoses for heartburn and dyspepsia; they are all acid-related problems which cause a similar, but often more severe, range of symptoms. Treatment of these conditions is usually under supervision of a doctor who might, as part of the treatment, suggest use of a non-prescription antacid/combination product.

Simethicone is a common ingredient in OTC remedies for infant colic, where griping tummy pain is thought to be caused by trapped or excess wind in a baby’s gastrointestinal tract.

Histamine H2-antagonists

H2-antagonists act to reduce stomach acid secretion by blocking the action of the mediator, histamine, at H2-receptors on parietal cells. These "antihistamine" drugs work exclusively at H2-receptors in the stomach; they have no effect on H1-receptors which are involved in allergy and are present in many other parts of the body.

H2-antagonists have been available for more than a decade as prescription drugs for use in the treatment and prevention of stomach and duodenal ulcers and for use in other acid-related problems, including oesophageal reflux, heartburn and dyspepsia. As a group, the H2-antagonists have had a good record of efficacy and safety, and for this reason several H2-antagonists have been deregulated from prescription only (POM) to over the counter pharmacy sale (P) in the UK.

H2-antagonists available over-the-counter include cimetidine, famotidine and ranitidine. They are indicated for short-term use in the symptomatic relief of heartburn, indigestion and excess acid (hyperacidity), at doses lower than the recommended prescription doses. A new indication is prevention of food-related indigestion.

An additional licenced indication for cimetidine is the prevention of night-time heartburn. Cimetidine is also available as an H2-antagonist / sodium alginate combination for use in heartburn with acid regurgitation.

 

Compared to the antacids, alginates and antiflatulents, the H2-antagonists as a group:

Acid secretion is reduced and acid-related symptoms relieved for 6-9 hours (depending on the specific product). The beneficial effects are not lost when the stomach empties.

Clinically significant drug interactions are rare with H2-antagonists at the low OTC doses, although cimetidine does have the potential to interact with some prescription drugs (e.g. anticoagulants [warfarin], antiepileptics [phenytoin] and antiasthmatics [theophylline]).

As a group, the H2-antagonists are generally well tolerated, especially at the lower OTC doses. Reported side effects at these low doses include headache, diarrhoea, constipation, dizziness and skin rash.