Doctors come clean about the ‘effectiveness’ of weight loss drugs

My blog of 6th December last year lamented the fact that much medical research focuses not on health itself, but supposed ‘markers’ for health such as blood pressure and cholesterol levels. The main point I was aiming to make here was that in assessing a medical treatment or drug, we all (doctors included) need to keep focused on its effects on health outcomes like risk of heart disease, cancer, diabetes and, most importantly of all, death.

I was therefore interested to read a commentary in this week’s edition of the Lancet medical journal which reviewed the benefits of drugs used to help promote weight loss. The review was written by Drs Raj Padwal and Sumit Majumbar from the University of Alberta Hospital in Edmonton, Canada. In it, the authors review the effects of 3 weight loss drugs, two of which, orlistat (Xenical) and sibutramine (Reductil) are generally available. Orlistat works by reducing the amount of fat absorbed from the gut, while sibutramine acts on the brain to suppress appetite. On average, orlistat and sibutramine bring about weight losses of 3 kg and 4-5kg respectively.

In their review, Drs Padwal and Majumbar went on to balance the apparent benefits of these drugs with their potential downsides. For instance, orlistat is associated with a range of side-effects which include flatulence, faecal urgency and oily leakage from the rectum (niiice). Sibutramine is known to have the potential to cause symptoms such as constipation, palpitations, raised blood pressure and sexual dysfunction.

Crucially, though, the authors of this review went on to ask serious questions about the effectiveness of these drugs in promoting not just weight loss, but health. They make the point that the assessment of weight loss drugs should include measures of their impact on obesity related conditions (e.g. diabetes and heart disease) and death related to these conditions. At present, we simply don’t have any published data on the effects of currently available agents on these critical ‘end-points’. Only when we do, they say, can patients and their doctors be confident that the putative benefits of these drugs outweigh their risks and costs.

When it comes to the area of medical research I often find myself being sharply critical of doctors, scientists and researchers. I do feel compelled to write about incidents where it seems we are being misled and misinformed.

However, there is no doubt that from time to time individuals in the scientific community will confirm my faith in human nature by giving what would seem to be a balanced, impartial appraisal of a particular approach or treatment. To my mind, Drs Padwal and Majumbar deserve a big pat on the back for producing a review which is seems to be light-years away from the usual pharmaceutical PR puff pieces that are all too often to be found in medical journals.


1. Padwal RS and Majumbar SR. Drug treatments for obesity: orlistat, sibutramine, and rimonabant. The Lancet. 2007;369:71-77

6 Responses to Doctors come clean about the ‘effectiveness’ of weight loss drugs

  1. Helen 12 January 2007 at 2:28 pm #

    My friend Carolyn and myslef have both tried the diet drugs mentioned. Both of us have medical conditions that contributed to the weight going on in the first place some 15 – 16 years ago. As our medical conditons are under control we both wanted to reduce some of the excess 80lbs weight. We are both 5’4″ and have tried Weight Watchers, Slimming World and Rosemary Connelly, joining a gym and in my case swimming 1/2 mile 5 days a week with no real success. Although in my case I have held the weight gain at bay for 10 years but not been able to reduce it by more than 20 lbs. My friend has gone down 45lbs and up again 3 times as I have slowly lost a 6 or 7lbs. Potentially quite depressing and tiring carrying around this extra weight continually although the Paul McKenna weight loss cd helps keep me positive if nothing else.
    We have different doctors. Orlistat was decided against and in November Carolyn was given sibutramine (Reductil) by her doctor and had good results. I don’t agree too much with her meal replacement diet as it may work short term but does not teach any long diet care.
    I have now started taking sibutramine (Reductil) and after initial side effects of feeling very cold and thirsty I must admit it is helpful. I still follow a high GI diet and exercise to a familar old excercise cd and I am getting some results. I will join Rosemary Connelly again next week as there was a free join coupon in my local paper and I think a combination of all these things will help me to my goal of a fitter, thinner me before next Christmas. The point is, I think the weight loss pills can help if used as part of an overall program.

  2. Helen 12 January 2007 at 2:59 pm #

    oops made a big mistake, said I keep to a “high” GI diet whereas I believe I meant a LOW GI, wholegrains, unprocessed, organic where possible, lots of vegetables and slow release foods.

  3. Angie Laib 13 January 2007 at 2:31 pm #

    I had to see my GP last October for a bad back. He didn’t examine me but just said I had to excercise and lose weight. I was over 5 stone overweight.
    He prescribed Reductil to help me lose weight. I was reluctant to try it as my apetite is not a problem just lack of exercise but I thought if the weight loss was quicker it would help my back. I took the pills for 3 weeks, I lost a grand total of 3 pounds while I took them. I couldn’t sleep, felt depressed, was constipated and always thirsty. All this with a bad back which turned out to be a slipped disc and trapped sciatic nerve. The insomnia was the worst as I feel the pain more at night.
    I stopped taking them and I have lost more weight since I stopped. I have also used the Paul McKenna CD which I think helped to curb my apetite over several months.
    The problem, in my opinion, is that some doctors are too concerned with targets. My GP told me he has a target to reduce obesity, which is a good thing. He was not concerned with the reason I had actually gone to see him for.
    Before these pills are prescribed the patient’s lifestyle (current eating habits and exercise and what they have previously tried) should be taken into account. None of that happened with me. When I have been since I have always seen his locum so I have not had a chance to tell him all this.

  4. stratty 14 April 2007 at 11:32 am #

    I wonder if people trying to lose weight are, without realising it, actually adding to their weight gain by using many of the ‘diet’ supplements (and ‘diet drinks’) which contain sweeteners?

    [Its worrying too that some diabetic foods also contain sweeteners considering that obesity can lead to diabetes, and quite a lot of vitamin supplements do also, including, but not limited to, many children’s chewable vitamins – try finding Vitamin C without aspartame, it isn’t easy!]

    Looks like sweeteners promoted under the word “diet” might well involved a large sprinkling of scientific fraud:


    February 16th, 2007

    “…The Division of Clinical Epidemiology of the University of Texas Health Center at San Antonio just reported a study by Sharon Fowler, MPH that reviewed eight years of data confirming a diet soda link to obesity. She said: “Something linked to diet soda drinking is also linked to obesity.

    An earlier study found weight gain among 78,694 women using artificial sweeteners: Stellman SD, Garfinkel L: “Artificial Sweetener Use and One-Year Weight Change Among Women. Prev Med 1985: 15: 195-202…”

  5. stratty 14 April 2007 at 11:46 am #

    Not only is it difficult to find vitamin C tablets (even non-chewable or soluble – sp?) without aspartame in it (even the assistant in Boots took a while finding one without), it can take a long and boring period of searching supermarket shelves to find any soft drink without it – particularly when you also having to look for its E number and the various other names for it, just as you thought you’d found one – and I’ve only found ONE toothpaste without it so far…and that has saccharin instead which may not be any better.

    Is it REALLY necessary to have aspartame in just about everything? And what exactly is the point of putting an unhealthy and unnecessary chemical into a health supplement like a tablet of Vitamin C which you’re going to swallow without tasting anyway?

  6. stratty 14 April 2007 at 12:55 pm #

    Dieting and want to avoid the fattening (and other) effects of sweeteners?

    UK Sweetener terms:

    Aspartame: E951, canderel, nutrasweet, ‘contains a source of phenylalalnine’, Equal.

    Acesulfame: E950, acesulfame-K, Sunett.

    Aspartame, Acesulfame-K and Erythritol mix: NouriSweet.

    Aspartame, Acesulfame and Sugar mix: Sugarlite

    Saccharin: E954, Hermesetas.

    Saccharin & Sodium Cyclamate mix: Hermasetas Gold, Cologran, Natreen.

    Sucralose (an organochloride): E955, Splenda, Altern. Liquid versions: Fiber-Fit, Splenda Syrup Sweet Base.

    I think thats most of them, good luck finding anything that isn’t obviously fresh and natural without at least one of the above in them 🙂

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