Julia Forbes

Julia Forbes, Registered Dietitian, Nutrilicious explores the latest truth behind the headlines devoted to one of the latest anti-obesity medications, Rimonabant and poses other questions about the psychological needs of the obese patient.

New anti-obesity drugs are continuing to be developed since the first one of its kind in 1893 (1). Over the years such treatment options for obesity have received their fair share of criticism, particularly when they have offered quick fix solutions to weight loss which resulted in inevitable regain of weight lost. We now know that when used in certain patients and in combination with other treatments and strategies they can offer sustainable weight loss. Keeping up to date with the latest research helps us to identify which patients can benefit most along with the side effects that we need to be aware of and the kind of support needed.

Earlier this year Rimonabant, one of the latest anti-obesity drugs, hit the media spotlight for being “The weight loss drug that has been linked to suicide” The Daily Telegraph June 25 2008.

This article explores the truth behind this headline and questions whether health professionals should also be placing a greater emphasis on the psychological management of obesity.

In parallel to the media frenzy ‘The National Institute for Health and Clinical Excellence’ (2) gave Rimonabant the all clear to be prescribed as a treatment option for obese and overweight patients. Rimonabant works by blocking the CB1 receptors in the endocannabinoid system (ECS) in the brain. This system regulates body weight, energy balance, glucose and lipid metabolism. Increased activity of the ECS will lead to increased appetite and fat accumulation (3) Therefore, Rimonabant works to inhibit the activity of the ECS which should lead to weight loss and other metabolic benefits (3).

The NICE guidelines state:

• Rimonabant should be used in those adults intolerant to or with no response to Orlistat (Xenical) and Sibutramine (Reductil). Both of which have been previously reviewed by NICE.
• Rimonabant should be used at the same time as a calorie-controlled diet and exercise.
• Rimonabant is approved to treat obese patients (BMI≥30kg/m²) or overweight patients (BMI >27kg/m²) with associated risk factors such as Type 2 Diabetes Mellitus and Dyslipidaemia.
• To stop the use of anti-obesity drugs if 5% of total body weight is not lost after six months. If the patient achieves success after six months, he/she should be regularly monitored.

So how do the media claims about suicide fit into the recommendations made by NICE? A series of RIO (Rimonabant in Obesity) trials were carried out to clarify it’s efficacy, safety and tolerability prior to it’s launch in July 06. The RIO trials also demonstrated it’s effectiveness in: weight loss, a reduction in waist circumference and improvements in lipid profile and glycaemic control (4). Ongoing major depressive illness and/or ongoing antidepressive treatment are listed as contraindications. It states clearly in the SmPC (Summary of product characteristics) (5) for Rimonabant that:

• Depressive disorders or mood alterations with depressive symptoms have been reported in up to 10% of patients.
• Suicidal ideation in up to 1% of patients on Rimonabant.
• Patients with current suicidal ideations and/or with a history of depressive disorder should not be started on the medication unless the benefits of the treatment are considered to outweigh the risks.
• Obesity is a condition that may be associated with depressive disorders and therefore this highlights the importance of a thorough patient history and assessment of the patient when considering such medication.

In relation to this, healthcare professionals may also want to consider other research which highlights the psychological components of obesity: A number of retrospective studies have found that low self efficacy (6), unrealistic weight goals(6) and poor coping mechanisms(7) are some of the contributing factors to weight gain post treatment. A more recent study looked at the psychological mechanisms (a range of specific behavioural, cognitive and affective factors) which could account for the lack of weight maintenance once treatment ends. It was found that psychological factors significantly impact on a patients need to eat to help regulate mood, avoid negative affect, or cope with stressful circumstances. These factors are likely to encourage weight regain (8). The above research supports the need for weight management programmes which include an element of behavioural therapy.

Conclusion

All drugs have side effects and there is some truth in the claims made by the media that Rimonabant can cause suicidal ideation. However, the research suggests that this risk is minimal i.e. in 1% of patients (5) and it is also subject to the adequacy of the medical history and assessment of the risks verses benefits for treatment. An accurate clinical assessment of the patient will help ensure that a patient receives support tailored toward their individual psychological needs, and will encourage compliance to their anti-obesity medication.

It is clear from the research that behavioural therapy should play a key role during and beyond anti-obesity medication therapy (6,7,8). It should be viewed as a vital adjunct to weight loss and weight maintainance. The National Obesity Forum support these ideas and recognise that obesity is a complex condition and can only be managed effectively through lifelong care (9, 10).

References

(1) Bray G.A (2008) Some historical aspects of drug treatment for obesity. Pharmacotherapy of Obesity.11-19

(2) Nice guidelines Obesity – Rimonabant – accessed on 17th September 2008.
http://www.nice.org.uk/Guidance/TA144

(3) Overview of the EC system – medscape – accessed on 16th September 16th 2008 http://www.medscape.com/viewarticle/508011_2

(4) Curioni C, André C (2008) Rimonabant for overweight or obesity (Review) The Cochrane Collaboration. Published by JohnWiley & Sons, Ltd – accessed on 17th September 2008.
http://www.cochrane.org/reviews/en/ab006162.html

(5) SmPC Rimonabant – accessed on 17th September 2008.
http://www.sanofi-aventis.co.uk/live/gb/en/layout.jsp?scat=1EC7066D-865F-4766-852F-B12EC5F86412

(6) Colvin RH, Olson SB (1983) A descriptive analysis of men and women who have lost significant weight and are highly successful at maintaining the loss. Addict Behav; 8: 287–295.

(7) Gormally J, Rardin D, Black S (1980) Correlates of successful response to a behavioral weight control clinic.J Couns Psychol; 27: 179–191

(8) Byrne S, Cooper Z, Fairburn C (2003) Weight maintenance and relapse in obesity: a qualitative study. International Journal of Obesity 27: 955–962.

(9) National Obesity Forum Guidelines on Management of Adult Obesity and Overweight in Primary Care – accessed on 17th September 2008. http://nationalobesityforum.org.uk/images/stories/W_M_guidelines/NOF_Adult_Guildelines_Feb_06.pdf

(10) National Obesity Forum - Long term maintenance – accessed on 17th September 2008 http://nationalobesityforum.org.uk/images/stories/PDF_training_resource/in-depth-long-term-maintenance.pdf