Anti- obesity Medications
Dr Terri Lynne South
Obesity is a complex medical condition that requires lifelong management. For some people medication is necessary as part of a multipronged approach.
There are currently 4 medications approved by the TGA (Therapeutic Goods Administration) for augmentation of weight control in Australia.
1. Orlistat (Xenical) - is an oral tablet taken up to 3 times a day that impairs fat digestion and absorption from the gut.
2. Phentermine (Duromine) - is an oral tablet taken once a day and acts on the brain to reduce hunger.
3. Liraglutide (Saxenda)- is a daily injection with a hunger-suppressing action and helps people to feel full after eating but with less food. Liraglutide can cause nausea which settles after continued use. The starting dose of 0.6 mg can be slowly increased up to 3 mg daily, if required.
4. Bupropion / Naltrexone (Contrave) -A combination tablet containing an antidepressant/anti smoking medication of bupropion and naltrexone (an opioid antagonist). This medication acts in the brain to reduce hunger and food cravings. The starting dose is one tablet daily, gradually increasing to two tablets twice daily.
There are 2 other medications in common use for weight control which do not (yet) have TGA approval and are considered “off label” and requires a doctor to be comfortable in prescribing in this way.
Semaglutide (Ozempic) - Semaglutide is approved in Australia for the treatment of type 2 diabetes. It is given as a weekly injection. Although this medication lowers glucose in patients with diabetes, it does not cause hypoglycemia (low blood glucose) in individuals who do not have diabetes.
Topiramate (Topamax)- Topiramate is an antiepileptic drug. It appears to reduce intake via altering appetite and taste.
Each of these medications have their own contraindications, different methods of administration, adverse effects, and costs. The cost may be as low as $75 a month to more than $350 a month.
The side-effects are different for each medication, but most include gut related concerns such as constipation and nausea. A dose that works well with no adverse effects for one individual could cause very severe and intolerable adverse effects in another. The same can be said regarding expected weight loss results. The product information will state average weight loss expectations, but individuals can vary greatly in their response. There are significant contraindications for each medication and the decision to start a medication (and for most people living with obesity continue in some form long-term) is not one to take lightly.
Patients should be routinely monitored for adverse effects and the response to treatment.
All anti-obesity medications (AOMs) should be seen as a tool to help with a back-bone of sustainable changes to lifestyle factors such as improved eating, sleep, stress and activity.
