It is widely recognised that the tsunami of obesity is closely followed by one of Type 2 diabetes with its associated impact on the population and health services, specifically heart disease, obstructive sleep apnoea (OSA), certain types of cancer and a decreased life expectancy.
The pharma industry has long recognised this and has provided a plethora of obesity treating drugs over the years including Phenterpamine/ Phenfluramine in the 1990s and more recently Rimonobant, Sibutramine and Xenical. Unfortunately, apart from Xenical, all have been withdrawn due to a variety of risks including cardiovascular and mental health. Clinicians who have prescribed Xenical, not to mention patients who have taken it, are all aware of its limitations of both weight loss (in the region of 5-10%) and significant gastrointestinal side effects. Newer agents in the pipeline including phentermine with topiramite have also had problems – in this case its appraisal being indefinitely suspended by NICE following authorisation refusal – highlighting the difficulty in developing medications for obesity. Not to be discouraged however comes another agent or rather the rebranding of the current diabetes drug Liraglutide, a GLP-1 analogue. Whilst for diabetes its maximum dose is 1.8mg per day (or 1.2mg as recommended by NICE), for obesity the 3mg dose has just received FDA authorisation. Results from the SCALE series of trials indicate weight loss of approximately 6% – significant but a level in keeping with earlier agents.
What the history of obesity medication has told us is that whilst animal studies often show promise, this is not always borne out in humans due to our complex relationship with food – physical, psychological and emotional. Furthermore, there is an argument that early reliance on pharmacological aids (for often minimal gain) reduces a patient’s motivation to make lifestyle changes which must be the corner stone of treatment. This is before the relationship with the fast food industry is addressed – but that is another debate.
Dr Mark Freeman