On 16th November 2007, the Prime Section’s headline of the Straits Times, “Want to slim down? Don’t count on weigh-loss drugs” would have a lot of Singaporeans and those reading in the air (e.g. Singapore Airlines) fitting their eyes on this piece of news.

What a great catchy headline as many Singaporean particularly the female population considered themselves overweight, judging by the continuous flood of slimming advertisements in all appropriate local media. Is this to wake Singaporean up as their online version was not punchy – “Weight loss drugs may slim users down – but at high costs” ?

It has been reported obesity and overweight affect over 1.1 billion individuals worldwide and are highly and increasingly prevalent chronic conditions associated with premature mortality, chronic morbidity, and increased healthcare use.

Apart from traditional non-medicinal herbal options, the commonly used treatments are through the use of anti-obesity drugs such as orlistat, sibutramine and rimonabant. They are approved for long term treatment of obesity and choked up an estimated US$1.2 billion in global sales in 2005. The 3 drugs are prescribed for severe cases of obesity as obese people can reduce their risk of getting diabetes by 30 to 40 percent if they were to lose 4 kg.

Orlistat also known as tetrahydrolipstatin is marketed under the trade name Xenical. Its primary function is preventing the absorption of fats from the human diet, thereby reducing caloric intake.

Sibutramine is marketed under the trade name Meridia in the USA and Reductil in Europe and other countries. It acts by increasing serotonin and norepinephrine levels in the brain. The S$4 pill makes the patients feel full with less food and is needed to be taken for between 6-12months.

Rimonabant which is also known as Accomplia, Riobant, Slimona, Rimoslim, Zimulti and SR141716, is an anorectic anti-obesity drug. Its main avenue of effect is the reduction in appetite. On 15 June 2007 the BBC News reported that a committee advising the US FDA has voted not to recommend the drug’s approval because of concerns over suicidality, depression and other related side effects associated with use of the drug.

The Straits Times report was following up on the British Medical Journal’s article published a day ago on their meta-analysis that :-

  • 30 per cent of patients on Xenical lost an average of 3 kgs and had unpleasant digestive and intestinal side effects, such as incontinence.
  • Patients on Reductil lost 4 kgs and had improved cholesterol levels. But up to 20 percent suffered from raised blood pressure and pulse rates, insomnia and nausea.
  • Patients on Accomplia lost the most weight – 5 kgs on average. Their blood pressure and cholesterol levels also improved but their risk of mood disorders rose 6 percent.

Straits Times reported that another study released on Friday by a different medical journal, The Lancet, found that patients on Accomplia were far more likely to suffer from depression, anxiety and, in severe cases, suicidal tendencies.

Thus the conclusion from the BMJ article is that “Orlistat, sibutramine, and rimonabant modestly reduce weight, have differing effects on cardiovascular risk profiles, and have specific adverse effects.”