The popularity of antiobesity drugs known as GLP-1 agonists has exploded in Australia, as in many other countries, in recent years.

One of those drugs, Ozempic (semaglutide), was initially approved and put on the Pharmaceutical Benefits Scheme (PBS) for the treatment of diabetes in 2018. Last year, the Therapeutic Goods Administration approved Wegovy (semaglutide) and Mounjaro (tirzepatide) for chronic weight management, allowing general practitioners (GPs) to prescribe these medications to patients with obesity or overweight, as well as to patients with weight-related comorbidities.

Administered via injection, GLP-1 agonists promote weight loss by acting on the brain to reduce appetite and increase feelings of satiety while simultaneously slowing down gastric emptying. Experts say that the boom in these medications corresponds with a much greater understanding of obesity.

“Our understanding of obesity has changed enormously over the last 20 years,” Priya Sumithran, MBBS, PhD, head of the Obesity and Metabolic Medicine Group in the Department of Surgery at Monash University in Melbourne, told Medscape Medical News. “We have a greater understanding of how complex its causes are, and that it is not caused by lifestyle habits alone. We also understand more about how excess weight can affect health.”

High Prices

Earlier this year, a Lancet Commission was set up to establish objective criteria for obesity diagnosis to aid clinical decision-making and improve the prioritization of therapeutic interventions and public health strategies. The Commission recognized that BMI-based measures of obesity can alternately underestimate and overestimate adiposity. It defined clinical obesity “as a condition of illness that, akin to the notion of chronic disease in other medical specialties, directly results from the effect of excess adiposity on the function of organs and tissues.”

In 2022, 66% of adults in Australia were overweight or obese, highlighting the need for more efforts to tackle the epidemic.

But while antiobesity drugs are improving thousands of lives across the country, their high prices mean that many are unable to afford the monthly dose, further deepening health inequities. Available only by private prescription, Mounjaro costs $395 per monthly dose, and Wegovy costs $460 per monthly dose.

Terri-Lynne South, MBBS, a GP and chair of the Royal Australian College of General Practitioners (RACGP) specific interest group on obesity, told Medscape Medical News that she supported the drugs’ availability on the PBS “because the people who need them the most are the ones who can least afford them. Obesity has greater prevalence in lower socioeconomic status suburbs,” she said.

“We have medicines on the PBS for blood pressure, diabetes, and cardiovascular disease, but we don’t have a single medication for obesity management, which is a chronic disease. We need to help the people who have the most severe forms of obesity, who need it the most.”

Although these medications can treat obesity, they are not a “silver bullet,” said South. “Losing weight doesn’t equal health,” she said. “These medications can help patients to get moving, lose weight, and reduce food noise, but they need to be added onto the bedrock of lifestyle interventions: improving diet and exercise,” she said.

“For my patients, I find those who are getting the best health outcomes have wraparound care and advice on muscle maintenance, physical activity, and how to use the medication as a tool to improve diet.”

Unequal Access

South added that she is concerned about patients who are not the target population for these drugs but who, she said, are manipulating online prescription services to access them.

Mark Mellor, MBBS, a specialist GP and founder of Perth Weight Clinic, told Medscape Medical News that he advocates for funded access to treatment for obesity for “those who want and need it.”

The RACGP’s expert obesity group has submitted a framework to the government outlining which patients they believe should be eligible for funded access: patients with clinical obesity with three obesity-related impairments or at least one severe obesity impairment.

“There’s inequity in access to treatment for people with obesity compared with other diseases because of historic stigma that largely sees it as a choice,” said Mellor. “These are people who need treatment now. They’re living with a chronic, systemic illness.”

“But I do believe the government wants to be able to fund it. It recognizes that it’s an epidemic and the driving force behind so many other chronic diseases we see. The challenge now is how to fund it. It’s very expensive.”

But like South, Mellor cautioned that GLP-1 agonists were only a tool. “These medications should not be prescribed by someone who doesn’t understand obesity and wraparound care. Treatment should always be holistic, patient-centered, and delivered with a clinician with access to multidisciplinary care.”

Potential Harms?

But not all experts agree with the use of antiobesity drugs. While such medications help those who have found it difficult or impossible to lose weight because of their biology, they also cause harm, Emma Beckett, PhD, adjunct senior lecturer in nutrition, dietetics, and food innovation at the University of New South Wales Sydney, told Medscape Medical News.

“They harm all of us because it’s making diet culture and fat phobia worse,” she said. “They also harm people who use them to suppress appetite but aren’t given the support to improve their diets at the same time, which leads to malnourishment. And they harm the people who can’t use them because of costs, side effects, or other health reasons. They will now be judged for not losing weight in the GLP-1 medication era, when everyone else thinks it must be so easy.”

These drugs should be subsidized by the government to improve access “if weight truly is the medical problem that it is framed as under the medical model of overweight and obesity,” Beckett said.

Yet she didn’t agree that these drugs necessarily would improve Australians’ health. “As more people go on these medications, we will see that weight loss alone doesn’t improve health in the way we have been conditioned to think it will,” said Beckett.

Sumithran has coauthored manuscripts with a medical writer provided by Novo Nordisk and Eli Lilly and Company and received payment from these companies (to the writer’s institution) for speaking and advisory activities. South has received honoraria for educational lectures, advisory boards, and travel to conferences or research from Novo Nordisk, Eli Lilly and Company, Nestlé, iNOVA, and Boehringer. Mellor reported receiving honoraria for speaking and advisory board services from Novo Nordisk, Eli Lilly and Company, and Nestlé Health Sciences. He has a financial interest in Perth Weight Clinic. Beckett reported having no relevant financial relationships.