At the Winnett Specialist Group, we recognise the pivotal role that GPs and health professionals play in supporting patients with weight management. As obesity rates continue to rise, it is crucial for healthcare providers to stay informed about the latest evidence-based treatments available. Our goal is to share our expertise and insights in a collaborative and educational manner, ensuring that patients receive the most effective and appropriate care for their weight-related concerns.
The Growing Role of Weight Loss Medications
Over recent years, the field of medical weight management has evolved significantly, with an increasing number of pharmacological options now available. While lifestyle modifications remain the cornerstone of weight management, for many patients, medications can provide an essential adjunct to improve outcomes. However, with the rapid emergence of new treatments, there has been a mix of enthusiasm and misinformation, making it vital for health professionals to have a clear understanding of how these medications work and for whom they are most suitable.
Mechanisms of Action
Weight loss medications primarily target appetite regulation and metabolic processes. Most work by influencing neurohormonal pathways within the brain to reduce hunger and cravings, while some also enhance energy expenditure. Understanding these mechanisms allows us to tailor treatments to individual patient needs.
Currently, there are seven primary weight loss medications, categorised as three oral options and four injectable treatments:
- Oral medications: Duromine (Phentermine), Topamax (Topiramate), and Contrave (Bupropion/Naltrexone) have been available for several decades and can be effective in select patient groups.
- Injectable medications: Saxenda (Liraglutide), Ozempic (Semaglutide), Wegovy (Semaglutide), and Mounjaro (Tirzepatide) are newer options that have demonstrated significant efficacy in both weight reduction and metabolic health improvement, particularly in patients with type 2 diabetes or metabolic syndrome.
Patient Selection: Who Benefits from Pharmacological Treatment?
Weight loss medications are not a universal solution, and patient selection is critical to achieving the best outcomes. While BMI remains a common guide, a more nuanced approach involves assessing a patient’s metabolic profile, comorbidities, and previous weight loss attempts.
General guidelines for prescribing weight loss medications include:
- BMI 25-30 (Overweight): Considered for patients with weight-related comorbidities such as insulin resistance, hypertension, or sleep apnoea.
- BMI 30+ (Obesity): Stronger indication for pharmacotherapy, particularly for patients struggling with lifestyle modifications alone.
- Pre-surgical weight loss: Medications can be used as a bridge to improve surgical outcomes in patients with a high BMI or significant visceral adiposity.
Addressing Safety and Misconceptions
A frequently asked question among health professionals is, How safe are these treatments?
The GLP-1 receptor agonists (Saxenda, Ozempic, Wegovy, and Mounjaro) mimic endogenous incretin hormones, improving glycaemic control while suppressing appetite. They are generally well-tolerated, with the most common side effects being gastrointestinal, such as nausea and mild diarrhoea. While there are contraindications -including a history of medullary thyroid carcinoma or pancreatitis- these medications are considered safe for long-term use in most patients.
Phentermine-based treatments like Duromine require careful monitoring due to their sympathomimetic effects, which can increase heart rate and blood pressure. However, in well-selected patients, they can be an effective short-term tool.
Where is the evidence these drugs work for weight loss?
The potency of Semaglutide was first confirmed in 2021 in The New England Journal of Medicine resulting in 14.9% weight loss compared to2.4% placebo in 1961 subjects over 68 weeks. A third of semaglutide group patients lost 20% of weight.
Furthermore, 84% of patients with pre-diabetes returned to normoglycemia, compared with 47.8% in placebo. Weight circumference in the semaglutide group was -13.4cm, compared with -2.4cm in placebo.
The dosing in the study was slightly higher than the dosage used in Australia and was 2.4mg weekly (Wegovy ®) compared with 1mg weekly (Ozempic).
The two drugs are essentially the same ingredient – and just have different dosages. The reason why Semaglutide has constantly been in shortage globally is because it is a very effective short-term weight loss solution. It also helps keep blood sugar under control for patients with diabetes.
Practical Considerations in General Practice
Given the increasing demand for weight loss medications, many GPs face challenges in accessing certain treatments. Supply shortages, compounded medications, and cost barriers can all impact treatment availability. Encouraging patients to source medications through approved channels ensures safety and efficacy, avoiding potential risks associated with unregulated compounding pharmacies.
A Collaborative Approach to Weight Management
At the Winnett Specialist Group, we strongly advocate for a holistic approach to weight loss. Combining pharmacotherapy with dietetic support, psychological intervention, and surgical options where appropriate leads to the best patient outcomes. We welcome referrals and collaboration with GPs and health professionals who are keen to integrate medical weight management into their practice.
By staying informed and working together, we can provide patients with evidence-based, compassionate, and effective weight management strategies that go beyond traditional diet and exercise advice.
We are always available to support our healthcare colleagues with educational resources, case discussions, and shared patient care. If you have questions or wish to discuss a case, feel free to reach out to us. Together, we can make a significant impact on the health and well-being of our patients.
Mr Jason Winnett
Laparoscopic and Bariatric Surgeon
P (03) 9417 1555 admin@winnettspecialistgroup.com.au
www.winnettspecialistgroup.com.au
Queens Terrace, 382 Victoria Parade, East Melbourne 3002
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