New diet pills Q&A

A pill “to help you drop a dress size” is to go on sale, the Daily Express has reported. The newspaper highlights the decision to release orlistat, a prescription-only obesity drug, for sale 'over the counter' at pharmacists. Pharmacists are required to weigh customers before they can sell them       the pills.

Several newspapers have reported on two commercially available pills designed to aid weight loss. The first pill, Alli (the brand name for low-dosage orlistat), can be bought by adults with a BMI of 28 or more. GlaxoSmithKline, which manufactures the drug, has said that clinical trials had shown “adding orlistat to a reduced-calorie, lower-fat diet, can help people lose 50% more weight than dieting alone”.

The second drug, Appesat contains a seaweed extract that swells in the stomach and tricks the dieter into feeling full. Its manufacturers said slimmers using the pill lost 10lbs (4.5kg) in three months.

How do the drugs work?

The over-the-counter Alli pill is a lower-dose version of the medication orlistat or Xenical, which is only available by prescription. It works by preventing the body from absorbing fats from the diet, thereby reducing calorie intake. People taking the drug should avoid fatty foods and stick to a reduced-calorie diet.

At the standard prescription dose of 120mg three times per day before meals, orlistat prevents approximately 30% of dietary fat from being absorbed. At the new over-the-counter dose of 60mg, the drug prevents absorption of around 25% of dietary fat.

Appesat contains a fibre complex that is extracted from seaweed. The manufacturers say it helps with appetite control by helping people to feel fuller while dieting. They claim that people taking Appesat felt up to four times more satisfied with the food they had eaten, compared to those who had not used the tablet. This apparently reduces the amount of food people want to eat, even if they are not actively on a diet.

Are there problems or side effects?

The main side effects of Alli are related to the gut. These include oily, diarrhoea-like stools that may leak. This occurs because orlistat blocks some dietary fat in the digestive system from being absorbed, which exits the body unchanged in the faeces. Other problems can include wind and frequent or urgent bowel movements and abdominal bloating.

There are several conditions that pharmacists should ask about, according to the Royal Pharmaceutical Society of Great Britain (RPSGB). There are also several different groups of people who should not take the Alli pill, including:

  • people who have a problem with absorbing nutrients,
  • pregnant or breastfeeding women,
  • people taking other medication such as ciclosporin, warfarin or other oral anticoagulants, and
  • people with a condition where the flow of bile from the liver is blocked

How effective is the drug?

In one-year clinical trials, about one-third to one-half of people achieved a 5% or greater decrease in body mass, although not all of this mass was necessarily fat. After orlistat was stopped, a significant number of subjects gained weight, with some regaining up to 35% of the weight they had lost. The drug also causes a reduction in the incidence of type 2 diabetes.

What do experts make of the drugs?

Some commentators have cautioned that people should still see their GP for advice because some of them would have clinically treatable causes for their obesity, and all of them would face the risks of related illnesses that need to be discussed.

David Pruce, director of policy and communication at the Royal Pharmaceutical Society, welcomed the drug, and Dr Matt Capehorn, from the National Obesity Forum said that the drug would not be a ‘magic bullet’ but could be effective and safe when included in a structured weight management programme.

Does taking these pills mean I can lose weight without exercising?

No. All weight loss drugs are designed to be taken by people who also make sensible lifestyle changes. Diet and exercise are important parts of this and should ideally be started before beginning treatment with orlistat or Alli.

The RPSGB says that people taking the Alli pill should eat a nutritionally balanced diet that is mildly reduced in calories. This diet should contain no more than approximately 30% of calories from fat, which equates to less than 67g of fat in a 2000kcal/day diet. A day’s intake of fat, carbohydrate and protein should also be evenly distributed over three meals.

Any diet and exercise programmes should continue to be followed even once treatment with orlistat or Alli has stopped.

How can my doctor help me lose weight?

As well as being seen by a pharmacist, some people will need to see their GPs because they are at increased risk for other diseases that may need treatment. Overweight or obese people are at increased risk of heart disease, stroke, some cancers, high cholesterol, type 2 diabetes and raised blood pressure.

Seeking weight loss treatments can be an important sign of a commitment to losing weight. Maintaining weight loss will also require behavioural and lifestyle change, and speaking to a GP or other health professional can be an important opportunity to seek advice and support to achieve these goals and successful weight loss.

NHS Attribution