THE EFFECTS OF DRUGS ON GASTROINTESTINAL TRACT

THE EFFECTS OF DRUGS ON GASTROINTESTINAL TRACT

The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. (The "digestive system" is a broader term that includes other structures, including the accessory organs of digestion). 

In an adult male human, the gastrointestinal tract is 5 metres (20 ft) long in a live subject, or up to 9 metres (30 ft) without the effect of muscle tone, and consists of the upper and lower gastrointestinal tracts .

The GI tract always releases hormones to help regulate the digestion process. These hormones include gastrin, secretin, cholecystokinin, and grehlin, are mediated through either intracrine or autocrine mechanisms, indicating that the cells releasing these hormones are conserved structures throughout evolution.

What are the types of drugs?

Drug abuse is a very common problem in most countries so it seemed like a good topic for a list. This is a list of ten of the most abused drugs .

ü    Heroin	ü    Ecstasy
ü    Cocaine	ü    Opium
ü    Lysergic acid diethylamide	ü    Marijuana
ü    Crack Cocaine	ü    Psilocybin Mushrooms
ü    Methamphetamine	ü    PCP (Phencyclidine)

Drug-induced injury of the gastrointestinal (GI) tract is increasingly common but generally under-recognized. Although there is an overwhelming number of drugs that are associated with adverse GI effects, there is a limited number of characteristic injury patterns that should prompt consideration of drug-induced GI pathology. These include the following: erosions, ulcers, and strictures; crystal deposition; parietal cell changes; reactive gastropathy; pseudodysplastic changes; microscopic colitis; infectious or necrotizing enterocolitis; ischemic colitis; focal active colitis; and increased epithelial apoptosis.

Drugs can have adverse effects on any part of the gastrointestinal (GI) tract from mouth to colon. It is essential that a detailed and accurate drug history is taken in patients presenting with GI complaints. Many drug-induced effects will regress or heal on cessation of treatment. Non-steroidal anti-inflammatory drugs (NSAIDs) are usually associated with gastric and duodenal ulcers but are also recognized to cause lichen planus in the mouth, oesophageal inflammation and strictures, and small bowel and colonic ulcers and strictures. A newer class of anti-inflammatory drugs, the cyclooxygenase-2 (COX-2)-selective inhibitors, have been developed and have a more favourable GI safety profile than standard NSAIDs. 

Besides that, acute diarrhoea, relapse of inflammatory bowel disease (IBD), microscopic colitis and acute pancreatitis are also induced by ingestion of standard NSAIDs. The calcium antagonists, phenytoin and cyclosporin, induce gum hyperplasia, particularly in patients with poor oral hygiene. Alendronate, a bisphosphonate, has been associated with development of oesophageal ulcers, and specific recommendations are now given to reduce this complication. Of the many different forms of colitis associated with drug ingestion, the most frequent is pseudomembranous colitis. This is a complication of antibiotics and is caused by the toxin produced by Clostridium difficile. Many drugs have been associated with the development of acute pancreatitis, although a definite cause and effect relationship has been shown for only a few drugs. These include didanosine, furosomide, corticosteroids, azathioprine and sodium valproate.  

Many medicines taken by mouth may affect the digestive system . These medicines include prescription (those ordered by a doctor and dispensed by a pharmacist) and nonprescription or over-the-counter (OTC) products. 

Although these medicines usually are safe and effective, harmful effects may occur in some people. OTC's typically do not cause serious side effects when taken as directed on the product's label. It is important to read the label to find out the ingredients, side effects, warnings, and when to consult a doctor.

We should always talk with our doctor before taking a medicine for the first time and before adding any new medicines to those we are already taking. Tell the doctor about all other medicines (prescription and OTC's) we are taking. Certain medicines taken together may interact and cause harmful side effects. In addition, tell the doctor about any allergies or sensitivities to foods and medicines and about any medical conditions we may have such as diabetes, kidney disease, or liver disease.

People with a food intolerance such as gluten intolerance should make sure their medicines do not contain fillers or additives with gluten . We should ask our doctor if we have any questions  about the medications we take. Besides that, we should always follow our doctor's orders carefully, and immediately report any unusual symptoms or the warning signs described below.

On the oesophagus, some people have difficulty swallowing medicines in tablet or capsule form. Tablets or capsules that stay in the oesophagus may release chemicals that irritate the lining of the oesophagus. The irritation may cause ulcers, bleeding, perforation (a hole or tear), and strictures (narrowing) of the oesophagus. The risk of pill-induced injuries to the oesophagus increases in persons with conditions involving the oesophagus, such as strictures, scleroderma (hardening of the skin), achalasia (irregular muscle activity of the oesophagus, which delays the passage of food), and stroke.

Some medicines can cause ulcers when they become lodged in the oesophagus. These medicines include cfmirin, several antibiotics such as tetracycline, quinidine, potassium chloride, vitamin C, and iron.The signs of this disease are, firstly, we could feel the pain when swallowing food or liquid. Next, feeling of a tablet or capsule "stuck" in the throat and also our face will turn dull because of the aching pain in our chest or shoulder after taking the medicines. 

The second part of gastrointestinal tract that could be affected by this type of drugs is Oesophageal Reflux. The lower oesophageal sphincter (LES) muscle is between the oesophagus and the stomach. The muscle allows the passage of food into the stomach after swallowing. Certain medicines interfere with the action of the sphincter muscle, which increases the likelihood of backup or reflux of the highly acidic contents of the stomach into the oesophagus.

Medicines that can cause oesophageal reflux include nitrates, theophylline, calcium channel blockers, anticholinergics, and birth control pills. When a person suffers from this disease, he or she could feel the heartburn which is a sign of indigestion. Besides that, after taking or having a meal, if he or she suffers this, he or she will feel the sensation of food coming back up into the throat . 

The third part of our gastrointestinal tract that could also be affected is the stomach. Human stomach is located between the oesophagus and the small intestine. It secretes protein-digesting enzymes and strong acids to aid in food digestion, (sent to it via oesophageal peristalsis) through smooth muscular contortions (called segmentation) before sending partially digested food (chyme) to the small intestines.  One of the most common drug-induced injuries is irritation of the lining of the stomach caused by nonsteroidal anti-inflammatory drugs (NSAIDs). 

NSAIDs can irritate the stomach by weakening the ability of the lining to resist acid made in the stomach. Sometimes this irritation may lead to inflammation of the stomach lining (gastritis), ulcers, bleeding, or perforation of the lining. In addition, we should be aware that stomach irritation may occur without having any of the symptoms below.

Older people are especially at risk for irritation from NSAIDs because they are more likely to regularly take pain medicines for arthritis and other chronic conditions . Also at risk are individuals with a history of peptic ulcers and related complications or gastritis. These individuals should tell their doctor about any of these previous conditions. Special medicines may be needed to protect the stomach lining.

The warning signs of this particular disease are firstly, the person will suffer from severe stomach cramps or pain or burning in his or her stomach or at the back of his body. Besides that, if he pass out, the stools will be black, tarry or even it could be bloody stools. He or she will also experience bloody vomit. Severe heartburn or indigestion will also be felt by him. Lastly, the person will experience diarrhea.

Drugs could also cause the delayed emptying of our stomach. Some medicines cause nerve and muscle activity to slow down in the stomach. This slowing down causes the contents of the stomach to empty at a slower rate than normal. Drugs that may cause this delay include anticholinergics and drugs used to treat Parkinson's disease and depression.

The warning signs if a person suffer from this disease are firstly he will feel nausea. Nausea is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It usually, but not always, leads to vomiting . He will also feel bloating . Apart from that, he will experience the feeling of fullness, and sometimes some people do vomit of food eaten many hours later. The pain in mid abdomen could also be felt by him. He will suffer heartburn or indigestion and the sensation of food that he has eaten will come back up into the throat.

As a precaution to avoid this from affecting us, we should eat frequently, but in small and a balanced meal. After eating, we should not lie down for about 30 minutes . And if any of the symptoms above still continue, we should tell our doctor. Our doctor may consider changing our dosage or even the medication that has been prescribed before. 

Our intestine is another organ that could be affected by drugs. Constipation takes place in our intestine and it can be caused by a variety of medicines. These medicines affect the nerve and muscle activity in the large intestine (colon). This results in the slow and difficult passage of stool. Medicines also may bind intestinal liquid and make the stool hard.

Medicines that commonly cause constipation include antihypertensives, anticholinergics, cholestyramine, iron, and antacids that contain mostly aluminium. A person who suffers this will have constipation that is severe or disabling or that lasts several weeks.

Apart from the diseases stated above, diarrhea is another effects of drugs on human. Diarrhea is a common side effect of many medicines. Diarrhea is often caused by antibiotics, which affect the bacteria that live normally in the large intestine.Antibiotic-induced changes in intestinal bacteria allow overgrowth of another bacteria, Clostridium difficile (C. difficile), which is the cause of a more serious antibiotic-induced diarrhea.

The presence of C. difficile can cause colitis, an inflammation of the intestine in which the bowel "weeps" excess water and mucus, resulting in loose, watery stools. Almost any antibiotic may cause C. difficile-induced diarrhea, but the most common are ampicillin, clindamycin, and the cephalosporins. Antibiotic-induced colitis is treated with another antibiotic that acts on C. difficile.

Diarrhea also can be a side effect of drugs that do not cause colitis but that alter the movements or fluid content of the colon. Colchicine is a common cause of drug-induced diarrhea. Magnesium-containing antacids can have the effect of laxatives and cause diarrhea if overused. In addition, the abuse of laxatives may result in damage to the nerves and muscles of the colon and cause diarrhea .

If a person suffers from diarrhea, usually when they were passing motion, their stool will be covered in blood, mucus or pus in the stool. He will also suffer the pain in the lower abdomen. And usually, the person will have fever. 

The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion. The liver is necessary for survival; there is currently no way to compensate for the absence of liver function long term, although liver dialysis can be used short term.

This organ plays a major role in metabolism and has a number of functions in the body, including glycogen storage, decomposition of red blood cells, plasma protein synthesis, hormone production, and detoxification. It lies below the diaphragm in the abdominal-pelvic region of the abdomen. It produces bile, an alkaline compound which aids in digestion via the emulsification of lipids. The liver's highly specialized tissues regulate a wide variety of high-volume biochemical reactions, including the synthesis and breakdown of small and complex molecules, many of which are necessary for normal vital functions .

The liver processes most medicines that enter the bloodstream and governs drug activity throughout the body. Once a drug enters the bloodstream, the liver converts the drug into chemicals the body can use and removes toxic chemicals that other organs cannot tolerate. During this process, these chemicals can attack and injure the liver. 

Drug-induced liver injury can resemble the symptoms of any acute or chronic liver disease. The only way a doctor can diagnose drug-induced liver injury is by stopping use of the suspected drug and excluding other liver diseases through diagnostic tests. Rarely, long-term use of a medicine can cause chronic liver damage and scarring (cirrhosis). Severe fatigue, abdominal pain and swelling, jaundice  (yellow eyes and skin, dark urine), nausea or vomiting are among the warning signs if a person has this problem.

As a conclusion, we should be wise in choosing the food that we eat, especially the medications that are prescribed on us. This is because, medications are drugs, but the drugs content in them are in a controlled dosage. That is why we should follow the dosage prescribed by our doctor, we should not take them as we like as the drugs in the medicines also could affect our body and its health, specifically or gastrointestinal tract or commonly known as our digestive system. 

Globally, drugs do affect the human digestive system as the number of people dying because of intestinal problem are quite serious. According to a recent statistic conducted by World Health Organisation, the percentage of people in Malaysia who died because of this disease in 1997 to 1999 is 15.96%. Same goes to India: 24.25% , Laos: 28.81% , Burma: 28.31% , Bangladesh: 25.2% , Thailand: 12.95% , Philippines: 13.78% , Indonesia: 15.69% , Cambodia: 32.31% , Saudi Arabia: 11.28%, United States: 7.35% , and overall all over the world, 15.3 % .