# ANTIDEPRESSANTS IN THE TREATMENT OF IBS



## eric (Jul 8, 1999)

FYIwith permissionTHE USE OF ANTIDEPRESSANTS IN THE TREATMENT OF IRRITABLE BOWELSYNDROME AND OTHER FUNCTIONAL GI DISORDERSChristine B. Dalton, PA-CLaura A. Keeter, MSIVDouglas A. Drossman. MDYour doctor has recommended the use of antidepressants for your symptoms from irritable bowelsyndrome (IBS) or another functional G.I. disorder. You may have questions and concerns about the useof these medications. The following information should help answer some of these questions.WHAT ARE FUNCTIONAL GI DISORDERS?There are more than twenty functional disorders of the gastrointestinal tract. Irritable bowel syndrome(IBS) is the most common and most thoroughly studied functional GI disorder.Functional GI Disorders are characterized by abnormal functioning of the gastrointestinal tract. This mayinclude, changes in the movement of the intestines (abnormal motility) or the sensations produced byintestinal activity (visceral hypersensitivity). One's awareness and interpretation of these activities may beabnormal perception).ABNORMAL MOTILITYInstead of the normal muscular activity (motility) of digestion, patients may experience spasms andcramping. If the motility is too fast, it might result in diarrhea and if too slow, it may result inconstipation. These two conditions may also produce abdominal discomfort or pain. Abnormal motilitycould also result in abdominal cramping, belching, urgency or other unpleasant GI symptoms.VISCERAL HYPERSENSITIVITYThere can also be increased sensitivity of the nerves in the GI tract. This can result in a lower thresholdfor experiencing intestinal sensation, leading to abdominal discomfort or pain.ABNORMAL PERCEPTIONWhen the nerve impulses from the gut reach the brain, they may be experienced as more or less severebased on one's mental and emotional state. For example, if someone is anxious or distressed, the pain maybe more severe. With functional GI disorders there may be abnormal increased perception of theseimpulses.WHY ARE ANTIDEPRESSANTS USED TO TREAT IBSSome medicines can have more than one action in treating medical problems. Aspirin, for example, canbe used to treat fever, headaches, muscle aches, and can also help prevent heart attacks.Although antidepressants were actually developed to treat depression, research studies have shown thatthey can also be effective as analgesics (drugs that reduce pain). Antidepressants are used to treat chronic,painful conditions like migraine headaches, diabetic neuropathy and fibromyalgia. Similarly,antidepressants are effective in treating symptoms of IBS and other functional GI disorders. Patients whohave taken antidepressants for their IBS symptoms have reported significant improvement in theirabdominal pain and reduction in other IBS symptoms, such as diarrhea, constipation, bloating, nausea orurgency.HOW DO ANTIDEPRESSANTS WORK IN IBS?The brain is always monitoring and processing everything that is going on in the body. Antidepressantsare known to work at the level of the spinal cord to block pain messages between the GI tract and thebrain (reducing visceral hypersensitivity). Certain antidepressants can also improve abnormal bowelfunctions that cause diarrhea, constipation, and other IBS symptoms. These medicines can also help withother problems like anxiety and depression, which are often associated with chronic painful disorders.WHEN ARE ANTIDEPRESSANTS USED FOR IBS?Patients with mild symptoms do not usually need antidepressants. Their symptoms may be controlled byother treatments. Patients with more moderate or severe IBS may benefit from taking an antidepressantmedication either alone or in addition to other treatments. The full effects of antidepressants typically takefour to six weeks to occur. Usually, low dosages are used to start and gradually increased as needed. Insome cases the low dose is sufficient to improve symptoms.WHICH ANTIDEPRESSANTS ARE USED FOR IBS AND WHAT ARE THEIR POSSIBLE SIDE EFFECTS?The most frequently prescribed antidepressants fall into one of two large groups; tricyclics (TCA's) andSelective Serotonin Reuptake Inhibitors (SSRI's).The TCA's have been on the market for many years, are relatively inexpensive, and have been used morefrequently in treating functional GI disorders.TCA's include:ï¿½ Amitriptyline (Elavil)ï¿½ Imipramine (Tofranil)ï¿½ ï¿½ Desipramine (Norpramin)ï¿½ Nortriptyline (Pamelor) and others.When first taking antidepressants, some people may NOTICE some side effects, but these usually goaway in a few days or weeks as their body gets used to the medicine.Common side effects of tricyclic antidepressants are dry mouth, or at times difficulty sleeping,difficulty urinating, sexual difficulties, constipation, dizziness and drowsiness.The SSRI's have been available for a shorter period of time, and can also be useful in treating IBS, alongwith associated symptoms, such as depression or anxiety. SSRI's include:ï¿½ Citalopram (Celexa)ï¿½ Paroxetine (Paxil)ï¿½ Sertraline (Zoloft)ï¿½ Fluoxetine (Prozac)Common side effects of SSRI's may include nervousness, vivid dreams, sleep disturbances, sexualdifficulties and diarrhea.Other types of antidepressants that may be used to treat IBS are:ï¿½ Bupropion (Wellbutrin)ï¿½ Venlafaxine (Effexor)ï¿½ Mirtazipine (Remeron)ï¿½ Trazodone (Desyrel)WHAT ARE COMMON CONCERNS ABOUT TAKING ANTIDEPRESSANTS?These medications are not addictive and do not change your personality or your thinking. Your physicianwill choose a particular antidepressant based on a combination of factors including your major symptomsof diarrhea or constipation, associated emotional symptoms (anxiety and depression), your generalmedical health, possible side effects (SSRI's have fewer effects on the heart), and possibly your previousexperience with other antidepressants.HOW LONG WILL YOU NEED TO TAKE ANTIDEPRESSANTS?This varies from individual to individual. Some may only need to take an antidepressant for 6 months to ayear. Many people, especially those with a longer history of IBS may need to take them longer. Thisdecision will depend on how you respond to the antidepressants, and whether symptoms recur when themedication is stopped or tapered.OTHER TREATMENTS USED IN IBSFirst-line therapy for IBS is often lifestyle modification. Keeping a diary of foods, situations, andemotions that may trigger symptoms can be helpful. You and your physician can develop strategies tohelp manage your symptoms. These can include dietary changes that can be helpful, such as:ï¿½ eating small, more frequent mealsï¿½ avoiding high fat foodsï¿½ increasing or decreasing fiberï¿½ eliminating or decreasing foods http://www.med.unc.edu/wrkunits/2depts/med...depressants.pdf


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