Yes, it is the common side effect. You may think for lower the dose or switch to other alternatives given below:
Many drugs are available to treat the symptoms of IBS, these drugs do not cure the condition. They are primarily used to relieve symptoms. The choice among these medications depends in part upon whether a person has diarrhea, constipation, or pain- predominant IBS. Furthermore, the effectiveness of specific drugs varies from one person to another. As a general rule, medications are reserved for people whose symptoms have not adequately responded to more conservative measures such as changes in diet and fiber supplements.
1. Anticholinergic medications :— Anticholinergic drugs block the nervous system's stimulation of the gastrointestinal tract, helping to reduce severe cramping and irregular contractions of the colon. Drugs in this category include dicyclomine (Bentyl®) and hyoscyamine (Levsin®). These drugs may be particularly helpful when taken preventively (ie, before symptoms) and thus are most helpful for patients who can predict the onset of their symptoms. Common side-effects include dry mouth and eyes and blurred vision.
2 A. Antidepressants : — Many tricyclic antidepressants (TCAs) have a pain relieving effect in patients with IBS. The dose of TCAs is typically much lower than that used for treating depression. It is believed that these drugs reduce pain perception when used in low doses, although the exact mechanism of their benefit is unknown.
TCAs commonly used for pain management include amitriptyline, desipramine, and NORTRIPTYLINE. Patients beginning TCAs commonly experience fatigue; this is not always an undesirable side effect since it can help improve sleep when TCAs are taken in the evening. TCAs are generally started in low doses and increased gradually. Their full effect may not be seen for three to four weeks.
TCAs also slow movement of contents through the gastrointestinal tract and may be most helpful in people with diarrhea predominant IBS.
[2 B]. Another class of antidepressants, the selective serotonin reuptake inhibitors, are recommended for people who have both IBS and depression. Common SSRIs include fluoxetine (Prozac®), sertraline (Zoloft®), paroxetine (Paxil®), citalopram (Celexa®), and escitalopram (Lexapro®) Other antidepressant medications that may be recommended include mirtazapine (Remeron®), venlafaxine (Effexor®), and duloxetine (Cymbalta®). (See "Patient information: Depression treatment options for adults").
3. Antidiarrheal drugs :— The drugs loperamide (Imodium®) or diphenoxylate with atropine (Lomotil®) can help slow the movement of stool through the digestive tract. Loperamide and diphenoxylate/atropine are most helpful in people with diarrhea-predominant IBS. However, clinicians usually recommend that these drugs should only be used as needed rather than on a continuous basis.
4. Anxiolytic drugs — Anxiolytic drugs reduce anxiety. Diazepam (Valium®) belongs to this class of drugs. Anxiolytic drugs are occasionally prescribed for people with short-term anxiety that is worsening their IBS symptoms. However, these drugs should only be taken for short periods of time since they can cause addiction and withdrawal syndromes.
5. Alosetron — Alosetron (Lotronex®) blocks a hormone that is involved in intestinal contractions and sensations. It is approved to treat women with IBS whose predominant symptom is diarrhea. However, it was withdrawn from the market soon after its introduction because of concerns related to safety. It was reintroduced and is currently available, although certain prescribing guidelines must be followed. Further information is available on the manufacturer's web site (www.lotronex.com).
6. Lubiprostone — Lubiprostone (Amitiza®) is available for treatment of severe constipation and irritable bowel syndrome in women >18 years who have not responded to other treatments. It works by increasing intestinal fluid secretion. It is expensive compared to other agents. Further testing is needed to clarify effectiveness and long-term safety.
7. Tegaserod — Tegaserod (Zelnorm®) is a prescription medication that was previously used for IBS symptoms. However, it was removed from the market in the United States in March 2007 due to concerns about an increased risk of heart attack, stroke, and severe chest pain. It was reintroduced in July 2007 for women under 55 who meet specific guidelines. Further information is available from the Federal Drug Administration's web site (www.fda.gov/bbs/topics/NEWS/2007/NEW016...
8. Antibiotics — The role of antibiotics in the treatment of IBS remains unclear. There appear to be some patients whose IBS symptoms are due to overgrowth of bacteria in the intestines and who may benefit from antibiotic treatment. However, more research is needed before antibiotics are recommended for treatment of IBS.