Irritable Bowel Syndrome/Phentermine /Nortriptyline


Hi. I have ibs-d. My gastro dr. put me on Nortriptyline. It has helped so much! I am on a very low dose of it. Well I am a bit overweight so I went to my family dr. He gave me Phentermine for weight loss. I take one nortriptyline everynight at 8:00. Will there be a problem if I take the Phentermine to. I know that you not my dr and you can't tell me what to do but I was just wondering if there would be a problem in mixing the meds. I don't want to stop taking the nortriptyline because it has helped me so much. My stomach was hurting really bad for years and finally I found something that helped it. On the other side of things I want to take the Phentermine for my weight loss. I thought because the one was such a low dose and I only take it one time a day at night that it may not be that big of a deal.


Hi Michelle, glad to hear the Nortriptyline is working well for you. It certainly is a good treatment option for some along with other IBS treatment options (you might like to read my treatment section on my web site, IBS Help Online for other options). Phenteramine is an amphetamine based drug, licensed for use in weight loss. It theoretically can interact with Nortriptyline with an increased risk of high blood pressure and also palpitations. Like most drugs, it can also cause a change in bowel habit, particularly diarrhea as well as drowsiness. However, I wouldn’t let that put you off, if it causes problems it can always be stopped!

Good luck.


Irritable Bowel Syndrome

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Dr Peter Thatcher MBBS, MRCPI. IBS Physician & Gastroenterologist


I can answer questions on all aspects of IBS or the Irritable Bowel Syndrome, Medicine and Gastroenterology. This would include aspects of diagnosis, investigation and management of IBS and other gastroenterology or medical conditions.


I am a Consultant Physician and Gastroenterologist in the United Kingdom. I qualified as a physician in 1993 and have been practicing Medicine and Gastroenterology ever since. I regularly run gastroenterology clinics and 1:4 patients have IBS. I am also the web master of IBS Help Online, an Irritable Bowel Syndrome help site.

British Society of Gastroenterology Member of the Royal College of Physicians of Ireland Consultant Physician and Gastroenterologist, Royal Cornwall Hospital, Truro, Cornwall. UK

Consultant Physician and Gastroenterologist, Fully UK Trained Medical Degree at Kings College School of Medicine & Dentistry 1993 Membership of the Royal College of Physicians of Ireland Examinations 1997

Awards and Honors
MBBS 1993 MRCPI 1997

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