Irritable bowel syndrome, or IBS, is a gastrointestinal disorder that results in significant pain and cramping, difficulty regulating bowel movements, gas and bloating. The cause of the disorder is unknown, but abnormal levels of serotonin in the intestines are reportedly related to the symptoms. One way to treat low levels of serotonin is using serotonin modulating drugs for IBS such as Lotronex and Zelnorm; however, significant side effects have been reported. Another method is the use of antidepressants that act on serotonin.
Symptoms of Irritable Bowel Syndrome
The most common symptoms of IBS are pain and cramping in the abdomen, diarrhea, constipation, and bloating. Some individuals suffer mainly from diarrhea, while others experience chronic constipation. Others may experience oscillation between the two conditions. Symptoms may be constant and chronic or may vary intensity. Symptoms may increase when taking certain medicines, eating large meals, eating certain foods such as those with caffeine, or when you are under stress.
5HTP and Serotonin
Serotonin is a neurotransmitter active in the brain and intestinal tract that carries messages in the body. 5HTP is the chemical precursor to serotonin, meaning that the body or brain needs 5HTP to produce or convert chemicals into serotonin. Approximately 95 percent of the body's serotonin is found in the intestines, while only 5 percent resides in the brain, Han van de Braak, chartered physiotherapist, registered acupuncturist and naturopath for the Integrated Medicine Practice in England. The cells in the intestines work to carry serotonin to other parts of the body, but individuals with IBS have less activity in these serotonin receptors and thus lower levels of serotonin in the intestines. This leads to difficulties with regulating bowel movements and a greater sensitivity to pain.
Serotonin Modulating Drugs for IBS
Some types of serotonin modulating drugs exist specifically for the treatment of IBS. They work by affecting the serotonin receptors of the nerves in the intestines. According to Harvard Health Publications, Lotronex is a serotonin antagonist. The FDA approved it for use in IBS-Diarrhea in 2000. It worked by blocking the activity of serotonin in the intestines. However, it was removed from the market after a few months due to serious side effects, including death. It was reintroduced in 2002, but with significant prescription restrictions. A similar drug, Calmactin, is being investigated, but there has been no definite support as of yet. Zelnorm is a serotonin agonist prescribed to treat IBS-Constipation, which helps keep serotonin available in the intestines. It reportedly increases bowel movements and reduces pain sensitivity; however, due to higher risk of heart problems, it is only prescribed for short time periods. Both drugs are only effective in women.
Antidepressants
A specific class of antidepressants that acts on serotonin in the brain are known as selective serotonin reuptake inhibitors, or SSRIs. They act to keep more serotonin available for the brain and body to use. SSRIs may help reduce abdominal pain when given as a low dose to persons with IBS. These drugs work to relax and make the intestines less sensitive to pain and contractions. They also impact the way pain is processed by the central nervous system or brain, which can help to alleviate pain. SSRIs are particularly beneficial for individuals with IBS, as well as a comorbid mood disorder.
References
- National Digestive Diseases Information Clearinghouse; Irritable Bowel Syndrome; http://digestive.niddk.nih.gov/ddiseases/pubs/ibs/
- Han van de Braak; Irritable Bowel Syndrome and what to do about it; Sept. 15, 2005
- Harvard Health Publications; Understanding and Treating an Irritable Bowel
- Help for IBS: Medications for Irritable Bowel Syndrome
- Life Extension Foundation: Irritable Bowel Syndrome
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