Lotronex is 5-HT3 receptor antagonist, a drug that affects the regulation of intestinal pain, colonic transit and secretions in the gastrointestinal tract. Lotronex is a drug created specifically to treat diarrhea-predominant Irritable Bowel Syndrome (D-IBS).
Wasn’t Lotronex taken off the market?Yes and no. Lotronex was removed from the market by the FDA in November of 2000 after 70 cases of adverse reactions to the drug, including 5 deaths, but is now available through a restricted drug distribution program. The main concern is the potential for damage to the intestine from either ischemic colitis or severe constipation. Ischemic colitis is a condition where blood flow to the intestine is decreased. The symptoms include pain, fever, and bloody diarrhea.
Only physicians who have enrolled in GlaxoSmithKline’s Prescribing Program for Lotronex should prescribe the drug for women with severe D-IBS (less than 5% of patients). Patients receiving Lotronex must read and sign a Patient-Physician Agreement.
How is Lotronex taken?Lotronex therapy is typically started with a dose of .5 mg twice a day for 4 weeks. If this dosage is well tolerated, but is not controlling IBS symptoms, the dose may be increased to 1 mg twice a day. If the drug is not tolerated or is not providing relief from symptoms after 4 weeks, it may be discontinued.
Why is Lotronex prescribed?Lotronex is only prescribed for women with severe D-IBS. It has not been proven effective in men with IBS.
What do I do if I miss a dose?If you miss a dose, take it as soon as you remember. If your next dose should be taken soon, just take that dose. Don't double up, or take more than one dose at a time.
Who should not take Lotronex?Tell your doctor if you have ever had any of the following conditions:
- Constipation
- Bowel blockage
- Blood flow problems to the bowels
- Blood clots
- Crohn’s disease
- Diverticulitis
- Ischemic colitis
- Ulcerative colitis
Side effects that should be reported to your doctor if they are severe or persistent include constipation, upset stomach, nausea, and abdominal gas, discomfort or bloating. Stop taking Lotronex and seek medical care immediately if you experience severe abdominal pain or cramping, a sudden worsening of abdominal pain, severe constipation, blood in the stool, difficulty in breathing, or swelling of the face, lips, tongue or throat. See the Lotronex side effects page for more information.
Are there any sexual side effects?The FDA has classified Lotronex as a type B drug. Studies on animals show no evidence of harm to the fetus, however there are no adequate, well-controlled studies in pregnant women. Lotronex should only be used in pregnant women when clearly needed.
What medications can Lotronex interact with?Lotronex is not currently proven to interact with any other drugs.
Are there any food interactions?There are no dietary restrictions necessary when taking Lotronex.
How long can Lotronex be taken safely?Lotronex is a new drug, and long-term effects are not currently known. Discuss the appropriate length of treatment with the prescribing physician. IBS symptoms may return within a week if Lotronex is discontinued.
