Pharmacotherapy for obesity
Scope of application
- BMI kg/m2: Pharmacotherapy can be considered in patients with a BMI of ≥30 kg/m2, or ≥27 kg/m2 with obesity-related complications if lifestyle therapy does not provide sufficient clinical benefit for patients.3
- Comprehensive disease management: Pharmacological treatment should be considered as part of a comprehensive strategy for disease management.4
- Post-bariatric surgery: There is also a role for pharmacotherapy post-bariatric surgery. 10-20% of all patients will regain all the weight they lost following bariatric surgery.10 In these cases, pharmacotherapy is recommended for patients with a partial weight loss response or who have experienced weight regain after bariatric surgery.11
Pharmacological treatments of obesity utilise different mode of actions and across the different classes, they can provide 3-9% weight loss.12
Benefits of pharmacotherapy include:
- Maintenance of compliance to lifestyle changes: Pharmacological management may be a useful adjunct to help patients maintain lifestyle changes that lead to a healthier weight.4
- Reduction of obesity-related health risks: Since pharmacological adjuncts can lead to potentially increased weight loss, this further decreases the risk of weight-related health problems such as osteoarthritis and sleep apnoea.2
- Improvement in quality of life: Pharmacotherapy has been shown to reduce the number of disability-adjusted life years, thus improving quality of life.4 This may be linked to increased maintenance of weight loss which has also been shown to cause marked improvement in quality of life measures.4
Types of pharmacological obesity treatments
Pharmacotherapy can be divided into non-prescription and prescription medications. Both are potential medical treatments for obesity but vary in efficacy.
Over-the-counter diet supplements for weight loss
Some diet supplements available without prescription claim to help with medical weight loss; however, there is little evidential basis to verify their use as weight loss treatments. In many countries, herbal products are classified under dietary supplements and therefore are not subject to regulatory testing and review, and therefore could be risky to health.
Prescription weight loss medications
Prescription weight loss medications are only available following prescription by a qualified health professional.
Different prescribed weight loss medications contain different types of medication and can have differing effects. Studies have shown that taking prescription weight loss medications can result in between 3-9% weight loss.12 Other studies have shown that some individuals (6-20%) taking prescription weight loss medications in conjunction with lifestyle changes both lose 10% or more of their initial weight and maintain that initial weight loss.13 This highlights the role of pharmacotherapy in augmenting weight loss or preventing regain after initial weight loss through lifestyle interventions.13
Mode of action
Anti-obesity medications can act directly on the central nervous system, inducing weight loss by reducing appetite, or act peripherally and induce weight loss by interfering with fat absorption from the gastrointestinal tract.14
Medications cannot replace key lifestyle factors such as regular physical activity or healthy eating habits. Prescription medications in conjunction to a lifestyle program have shown clinically meaningful weight loss results, thus a combination approach is recommended.13 It is also important to consider the side effects of prescription medications and a risk-benefit analysis should be performed prior to prescription. Delivering the best treatment for obesity should always be holistic and consider the patient’s needs.
For more guidance on Pharmacological Treatment Options, see page 102 of the AACE/ACE Guidelines (2016).