MEDICAL MATTERS:An over-the-counter medicine for weight loss is coming to a pharmacy near you later this year, writes MUIRIS HOUSTON.
LAST WEEK, the pharmaceutical company Glaxo Smith Kline (GSK) announced that it had received approval to market its weight- loss product orlistat, as an over-the-counter (OTC) product. It is the first time that a non-prescription medicine for weight loss will be available in the Republic and all 27 EU member states.
Readers may be familiar with the drug under its current trade name, Xenical. It has been prescribed by doctors for 10 years as part of an overall dietary plan for people who are overweight or obese.
The experience with it has been good and the decision to place orlistat on the OTC register under the trade name Alli, albeit at half the dose prescribed by doctors, reflects its safety credentials.
While the drug may very rarely cause side effects such as bowel inflammation and hepatitis, bloggers in the US, where orlistat has been available without prescription since 2007, are open about one major drawback. If you stray too far from the recommended low-fat diet, you are likely to soil your pants.
Because the diet pill works by blocking 25 per cent of fat from being digested, those who exceed the recommended fat intake are likely to experience at least some faecal discharge, if not the sudden and unwelcome appearance of a stool.
Although this represents a challenge for first-time users, the side effect does have the advantage of reinforcing behavioural change. If you cheat on your diet, you pay a penalty, which is an incentive to reduce your fat intake so as to avoid social embarrassment and which happily will also help you lose weight.
Research has shown that, for every 2lbs lost by diet alone, Alli could help lose an additional 1lb. In weight-loss terms, this 50 per cent boost is highly significant.
With the exception of Xenical, weight-loss drugs and supplements have a chequered and somewhat murky history. In the past some diet pills have worked by speeding up the entire body.
The problem with this blunderbuss approach is twofold: it caused heart problems, including valve abnormalities; and some people became over fond of the “rush” associated with certain drugs.
You will still find these “fast burners” advertised as additives to weight-loss supplements. Bitter orange is a stimulant you should avoid: it has been linked to stroke and heart problems in healthy people. Green tea has also been hyped as a fat-burning agent, but the evidence is slim.
Certainly there is no research showing that taking green tea extract helps reduce body weight. And CLA (conjugated linoleic acid) may cause insulin resistance – a precursor to type 2 diabetes – in people with abdominal obesity.
Rimonabant (Acomplia) is a weight-loss drug that did make it onto the market, but was withdrawn for use in the Republic last October, because of adverse psychiatric effects associated with its use.
Acomplia’s original 2006 authorisation stated it was to be used “as an adjunct to diet and exercise for the treatment of obese patients or overweight patients with associated risk factors such as type 2 diabetes or dyslipidaemia [high cholesterol]”.
In November 2007, an analysis of four clinical trials of Acomplia published in The Lancetfound that people taking the drug were two and a half times more likely to stop the drug because of depression and three times more likely to drop out of the studies because of anxiety.
The findings caused particular concern because the drug trials specifically excluded people with existing depression or a past history of the illness.
A further concern is that up to 48 per cent of people who are obese have depression, so giving a drug that increases the risk of psychiatric side effects to a vulnerable group is highly questionable.
The Acomplia saga confirmed the risks associated with anti-obesity drugs that work through the central nervous system. Even though a quarter of us are obese and at risk of major health complications, having a treatment that is worse than the disease will never be a solution to the problem.
- Dr Houston is pleased to hear from readers, but regrets he is unable to reply to individual medical queries