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Ten top tips - Weight loss using medication

GP Dr David Haslam gives his hints to effective use of pharmacotherapy for weight loss

GP Dr David Haslam gives his hints to effective use of pharmacotherapy for weight loss

1 Make an assessment of the patient's readiness to change

Make sure your patient wants to lose weight for the right reasons, and that they have a long-term view. If weight loss isn't one of the most important things in their life it may not be the best time to start a weight loss programme, for them, or for you.

2 Keep the advice simple

Small dietary and physical activity changes really do add up. Ask them to keep a food diary for a week. Encourage them to buy a pedometer to assess physical activity levels. Agree several simple changes they can choose to make and keep to and monitor their progress over several months. Offer monthly appointments, with a GP or nurse.

3 Look for evidence of lifestyle change before prescribing

Make sure you see results before prescribing. Guidelines suggest at least three months of lifestyle change before prescribing weight loss medication. This may be assessed through documented changes (food diary), increased and regular exercise, or observed weight loss. Even 1-2kg over a month shows good intent, and action speaks louder than words. Make a baseline assessment of their biochemistry, lipids, glucose and BP.

4 Set early goals and long term aims with your patient

Both doctor and patient need to know where this is going. Long-term aims might be simply weight loss or becoming fitter and able to play football with the kids, or take that beach holiday, or even better to improve diabetes or blood pressure control. Short-term goals can be becoming more active, cutting back on booze or high-fat snack foods. A reasonable initial goal is an average weight loss of 0.5-1kg per week.

5 Choose carefully which drug to use with your patient

The drug that works best is the one the patient wants to take. Discuss how they work with your patient and make the decision together. Three drugs are currently available:

• Orlistat, a gastrointestinal lipase inhibitor that reduces absorption of triglicerides from the small gut and reduces absorption by one-third. A low-fat diet is essential. Side-effects can be oily stools, abdo cramps or diarrhoea. A smart patient will quickly work out how to avoid fatty foods.

  • Sibutramine, a centrally acting serotonin and noradrenaline re-uptake inhibitor, enhances satiety and reduces calorific intake by about 20%. Side-effects are constipation, dry mouth and headache, and 5% of patients experience a small rise in blood pressure or pulse requiring cessation of treatment.
  • Rimonabant is the new kid on the block. An endo-cannibinoid blocker, it acts centrally and peripherally to increase the sensation of fullness and reduce food intake. Commonly encountered side-effects are dizziness, anxiety, and depression, which stops on cessation.

All three drugs can help achieve very similar weight loss results, about 8-9 kg from baseline over six to 12 months.

6 Check for drug interactions

Safety is paramount. Users of orlistat theoretically risk reduced levels of fat-soluble vitmans A, D, E and K but in practice this rarely occurs. Sibutramine is contraindicated in cases of pre-existing CHD, poorly controlled blood pressure, thyrotoxicosis, and SSRI treated depression and has some significant drug interactions. Rimonabant is considered unsafe in patients with active or recent depression. Familiarise yourself with the SPC of all three medications.

7 Expect an average of 0.5-1kg per week weight loss

Weight lost on medication varies widely, but averages 0.5-1kg per week over a three-month period. On some appointments when weight loss is not realised it's important to encourage your patient to continue, even intensify their resolve and to continue to accept the ebb and flow, as long as the overall spiral is downwards. Continue to explore further small changes as the months go by. Keep pointing out where positive change has occurred and encourage them.

8 Ask about side-effects

When reviewing your patient, proactively enquire about side effects – they are common and may not be directly attributed to the medication by them. If excessive they can deter patients from continuing their prescription; if not discussed they can't be minimised (such as renewed emphasis on a low-fat diet if using orlistat). Monitor blood pressure and pulse every two weeks with subutramine for at least three months and monthly thereafter. Psychological changes with rimonabant can be sudden and severe. Onset of depression or suicidal thoughts should result in the medication being stopped immediately.

9 Encourage the use of patient-support programmes

There's evidence that the free support programmes provided by all three manufacturers can, by use of websites, support materials and direct phone calls, improve overall effectiveness of treatment and improve weight loss, and patient satisfaction with their weight loss programme. They provide valuable ongoing support that will work with you, not against you, help the patient set reasonable goals, and encourage them when the going gets tough.

10 Make sure lifestyle change will last longer than prescription

Inevitably prescription medication will stop. Sibutramine is licensed for 12 months, orlistat open-ended, rimonabant yet to be appraised by NICE. To make weight loss meaningful, to ensure your efforts are fruitful, and to ensure health benefits are gained weight loss has to be long term. Obesity can never be cured, just controlled and the only way to achieve that is to ensure that your patient embarks on lifelong lifestyle changes that will continue long after medication has stopped. The time to start talking about this is right at the beginning, and continue throughout the programme. It can't be emphasised enough.

Dr David Haslam is a GP in Watton-at-Stone, Hertfordshire, and clinical director of the National Obesity Forum.

Dr Haslam has acted as an adviser to Roche, Abbott, Sanofi, GSK, Pfizer, and MSD, and surgery, food and activity companies. He provides submissions for QOF, NICE, the DoH, the Health Select Committee and other bodies.

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