Digestion, General | March 1, 2016 | Author: The Super Pharmacist
Gastro-oesophageal reflux disease (GORD) is a condition in which stomach acid 'backs up' into the oesophagus, or the tube connecting the mouth to the rest of the gastro-intestinal system1. This disorder, also known as GERD or acid reflux, may cause the taste of acid or bile in the back of the throat, discomfort, and pain in severe cases1. GORD may be mild, moderate or chronic, and may also increase the risk of other gastrointestinal disorders. The development of Barrett's oesophagus, a condition in which the cells of this tube are transformed or altered in a way that makes them resemble cells of the small intestine, may be influenced by pre-existing GORD2. This disorder, in turn, increases the risk of cancer in the upper gastric tract3,4. Other consequences of GORD include inflammation and wearing away of the lining of the oesphagus over time, which may lead to blood loss1. The prevalence of GORD may be as high as 20% in Europe and North America1. GORD may develop as a result of the decreased integrity of the connection between the oesophagus and stomach. This is mostly controlled by the lower oesophageal sphincter, a muscular valve that should relax to allow food into the stomach, and then contract when eating (or rather swallowing) has stopped. However, in the course of the progression of GORD, this valve becomes increasingly relaxed at inappropriate times, which may result in the involuntary regurgitation of acid (and possibly undigested food particles) back up into the throat5. This is known as transient lower oesophageal sphincter relaxation5. The risk of developing GORD may be affected by many factors and other conditions. These include:
GORD may be treated with a variety of therapies and strategies. These include:
Intermittent eating patterns are strongly associated with the development of GORD. Snacking between meals may further distend the stomach and increase lower oesophageal sphincter relaxation13. This may be addressed by implementing and maintaining a more regular meal-based eating regimen, with reduced snacking and more fluids between meals13. Weight loss may be associated with an improved response to treatment in patients with GORD14. In the case of GORD during pregnancy, the pressure on the stomach may be alleviated by taking increased amounts of small meals during the day, rather than three or four larger ones15. GORD may occur while sleeping; therefore, raising the head of a bed by about 15cm to reduce mechanical stress on the stomach during this time, may be helpful16,17. Patients with GORD may also benefit from a reduced intake of acidic foods and polyunsaturated fatty acids6.
These are products containing such ingredients as sodium bicarbonate or calcium carbonate, which can neutralise hydrochloric acid (HCl), which is produced in the stomach to break down food, and may be pushed back up through the oesophagus in an attack of GORD18. Pregnant women should not take antacids containing sodium bicarbonate, as they may increase water retention19.
These are histamine receptor-2 (H2) antagonists, that can prevent the production of HCl from cells in the stomach lining18. This will reduce the availability of acid to irritate or inflame the oesophagus at the onset of GORD. The most common choice is ranitidine.
If the above treatment options fail or patients require long-term relief, patients may be advised to switch to proton pump inhibitors (PPI's). These drugs also reduce stomach acid production by decreasing the availability of the molecular 'raw materials' required by cells to do so. There are several types of proton pump inhibitors available. These include1; Pantoprazole, Esomeprazole, Lansoprazole, Omeprazole and Rabeprazole. Proton pump inhibitors are indicated for many symptoms and complications of GORD, including:
1. Symptoms without complications A systematic review of 3 trials of proton pump inhibitors found that esomeprazole (20mg), omeprazole (20mg), pantoprazole (20mg) and rabeprazole (10mg) were equally effective in treating reflux without inflammation or eosophageal lining damage20. The data on complete symptom resolution is limited in both quality and quantity, but indicates that all five subtypes are equally effective in this20. Lower doses of these drugs may be recommended for long-term therapy due to the risks of side-effects21. A review of 11 studies indicated that there was no difference in the long-term symptom management of high- and low- dose lansoprazole. However, remission times for high-dose rabeprazole and omeprazole were superior to those of lower doses of the same drugs20. There was no conclusive data on these differences between high- and low-dose omeprazole20.
2. Oesophageal inflammation and/or oesophageal damage These complications, also known as oesophagitis, may also be treated with proton pump inhibitors. A review of 16 trials found no difference between the various subtypes in relieving oesophagitis20. Esomerprazole (40mg) was found to be more effective in the healing of moderate to severe oesophagitis at 4 weeks (but not 8 weeks) into treatment compared to an equal dose of pantoprazole20. This dose of esomerprazole was also found to be superior to lansoprazole (30mg) and omeprazole (20mg). Rabeprazole, omeprazole and lansoprazole were found to be equally effective in promoting the remission of inflammation. Two studies found that pantoprazole (20mg) had a higher rate of relapse in this complication compared to the same concentration of esomeprazole. Systematic review of these drugs indicates that they are generally comparable in efficacy, safety and side-effect profiles20. The data on which proton pump inhibitor is associated with the highest incidence of adverse effects is poor and limited20. However, this indicates that all five subtypes have an equal probability of these, which may include diarrhoea, an increased risk of gastric bleeding or cancer, pneumonia and bone fractures20,21. On the other hand, pantoprazole is regarded as having a higher bioavailability and a lower rate of interaction with other drugs22. These interactions may include an increased risk of cardiovascular events when taken with clopidogrel. However, a recent clinical trial showed that the co-administration of omeprazole with this drug reduced the risk of gastrointestinal bleeding without an increase in cardiovascular risk21.