Anti Obesity Medications
What are Anti Obesity Medications?
Anti Obesity Medications have been available in Australia and throughout the world for several decades.
These medications included oral medications such as Xenical, Duromine, Contrave, Metformin, Topiramate.
More recently injectable weight loss medications have become available that mimic certain GUT Hormones (Hormone GLP1) that control appetite and how we feel when we eat. These include Trulicity, Saxenda, Ozempic, Wegovy, and Mounjaro.
In Australia, Anti Obesity Medications can be prescribed by doctors such as General Practitioners, Endocrinologists, Bariatric Physicians and Bariatric Surgeons.
Your Doctor will choose which medication may be most suitable for you. As with most medications, there are some potential side effects that may vary depending on yourself and on the product.
Most Anti Obesity Medications are not PBS listed and carry a significant cost.
As with most medications, the effect of the Anti Obesity Medication wears off once the medication has ceased.


Types of Anti Obesity Medications
TABLETS:
- Duromine
- Topiramate
- Contrave
- Metformin
INJECTIONS:
- Trulicity
- Saxenda
- Ozempic
- Wegovy
- Mounjaro
How Do Anti Obesity Medications Work?
Medications which are taken orally as a tablet form such as Metformin, Duromine, Contrave, and Topiramate all work in different ways according to the particular medication. Generally, these medications reduce a patient's appetite and may reduce cravings.
Injectable weight loss medications mimic certain GUT Hormones (Hormone GLP1) that control appetite and how we feel when we eat. They often cause patients to snack less and eat smaller portions. These medications include Trulicity, Saxenda, Ozempic, Wegovy, and Mounjaro.
What are the Advantages of Anti Obesity Medications?
The benefits of Anti Obesity Medications are often improved if patients combine these with a healthy diet, healthy eating behaviours and regular physical activity.
GLP1 AGONIST (Ozempic, Wegovy, Mounjaro, Saxenda, Trulicity) MEDICATIONS-EFFECTS ON THE BODY
* Decreased appetite
* Decreased food intake
* Increased Satiety
* Decreased body weight
* Increased Insulin
* Decreased hyperglycaemia
* Increased Insulin sensitivity
* Decreased gastric emptying - slower emptying of stomach
GLP1 AGONIST (Ozempic, Wegovy, Mounjaro, Saxenda, Trulicity) MEDICATIONS-BENEFITS TO HEALTH
* Decreased death from cardio-vascular disease
* Decreased incidence of heart attack
* Decreased incidence of stroke
* Decreased blood pressure
* Decreased fatty liver disease
* Decreased inflammation
* Decreased body weight
WHAT ARE THE DISADVANTAGES OF INJECTABLE WEIGHT LOSS MEDICATIONS (GLP1 AGONISTS)
Most Anti Obesity Medications are not PBS listed and carry a significant cost
The high cost associated with taking Anti Obesity Medications long term often leads to many patients having to stop these medications
Up to 1/3 patients have ceased OAMs by 1 month in some practices due to cost or side effects
Up to 2/3 patients have ceased OAMs by 3 months in some practices due to cost or side effects
Patients are more likely to cease medications if not prescribed by a specialist
Many patients regain their lost weight within 12 months of ceasing medications
Anti Obesity Medications may need to be ceased if certain side effects occur
As with certain medications, the effect of Anti Obesity Medications may diminish over time in some patients
Disadvantages of Injectable Weight Loss Medications (GLP1 Agonists)
AVOID or USE CAUTIOUSLY
Medullary Thyroid Carcinoma, MEN2
History of Pancreatitis
Severe GI disorders (eg. Gastroparesis)
Pregnancy
POSSIBLE ADVERSE EFFECTS/ POSSIBLE SIDE EFFECTS OF INJECTABLE WEIGHT LOSS MEDICATIONS (GLP1 AGONISTS):
Nausea, Vomiting, Diarrhoea, Early Satiety
Pancreatitis
Gallstones
Delayed Gastric Emptying
Thyroid C cell tumours
Acute Kidney Injury
Hypoglycaemia
When to use different Anti-Obesity Medications:
HUNGER CONTROL, PORTION CONTROL - GLP1’s - Saxenda, Ozempic, Wegovy, Mounjaro
SNACKING AND CRAVING - Contrave
SWEET CRAVING AND FATIGUE- Phentermine
SWEET CRAVING / HEADACHES- Topiramate
WEIGHT REGAIN FROM MENTAL HEALTH MEDICATIONS -Metformin
GLP1 AGONIST MEDICATIONS-INDICATIONS FOR USE
BMI>27 WITH COMORBIDITIES OR BMI>30 WITH NO COMORBIDITIES
Not a candidate for surgery
Preoperatively for BMI>60
Within 3months Weight Loss Surgery if not on expected weight loss curve
Weight regain post Weight Loss Surgery
TABLETS:
DUROMINE:
Phentermine
Dosage: 15-30mg weekly
Not PBS listed
Expected weight loss: - 12 weeks of treatment - 5-10% TWL (Kang et al. 2010)
Cost per Month: $90-$170/month - depending on dose and place of purchase
Cost per Year: $1,080-$2,040/year - depending on dose and place of purchase
CONTRAVE:
Naltrexone/Bupropion
Dosage: 8mg/90mg daily - dose increases from 1-4 tablets/d
Not PBS listed
Expected Weight Loss: - 56 weeks of treatment - 5.4% TWL (Greenway et al. 2010)
Cost per Month: $249/month - depending on dose and place of purchase
Cost per Year: $2,988/year - depending on dose and place of purchase
TOPAMAX:
Topiramate
25mg -200mg daily
TGA approved for migraines and epilepsy
Not PBS listed
Bray et al. 2003 -24weeks of treatment - 5% TWL
$10-$23/month - depending on dose and place of purchase
$60-$141/year - depending on dose and place of purchase
MOUNJARO:
Tirzepatide
2.5mg – 15mg weekly
TGA approved for T2DM
Not PBS listed
Surmount Trial - 72 weeks of treatment - 15-20.9% TWL
$285-$719/month - depending on dose and place of purchase
$3,420-$8,628/year - depending on dose and place of purchase
WEGOVY:
Semaglutide
0.25mg-2.4mg weekly
TGA approved for weight loss
Not PBS listed
Step1-4,5,8 and Select Trials - 68-208 weeks of treatment - 14.9-18.5% TWL
$260-$645/month - depending on dose and place of purchase
$3,120-$7,740/year - depending on dose and place of purchase
OZEMPIC:
Semaglutide
0.25mg – 1mg weekly
PBS listed for T2DM
Not PBS listed for weight loss
Sustain 7 Trials- 40 weeks of treatment - 6.5% TWL
$130-$200/month - depending on dose and place of purchase
$1,560-$2,400/year - depending on dose and place of purchase
SAXENDA:
Liraglutide
0.6mg – 3mg daily
TGA approved for weight loss
Not PBS listed for weight loss
Step 8, Scale and Leader Trials- 56-68 weeks of treatment - 6.4-8% TWL
$400/month - depending on dose and place of purchase
$4,800/year - depending on dose and place of purchase
TRULICITY:
Dulaglutide
1.5mg weekly
TGA approved for weight loss
PBS listed for T2DM
Sustain 7 Trial- 40 weeks of treatment - 3% TWL
$150/month - depending on place of purchase
$1,800/year - depending on place of purchase