Introduction
Weight loss is a complex journey that often requires more than just willpower. The cornerstone of any weight loss therapy should be behavioral intervention, caloric intake reduction, increased caloric expenditure, exercise, and a balanced diet rich in micronutrients. But, medications and surgical options are also available. This article aims to provide a comprehensive review of currently available weight loss medications, offering insights into their mechanisms, dosages, side effects, and costs.
Orlistat (Xenical®)
Mechanism of Action (how it works):
Orlistat inhibits the absorption of fats in the gastrointestinal tract.
Dosage:
The usual dose is one 120mg capsule up to three times a day with meals.
Side Effects:
Common side effects include gastrointestinal issues like diarrhea and flatulence.
Considerations:
Orlistat may not be suitable for those with malabsorption syndrome or gallbladder problems.
Average weight loss after 1 year: -10.2% vs -6.1% placebo (4.1%)
Cost:
Estimated cost: $150/month.
Naltrexone/Bupropion (Contrave®)
Mechanism of Action:
Contrave combines naltrexone, an opioid receptor antagonist, and bupropion, an antidepressant. This combination acts on the brain’s appetite and food craving centres.
Dosage:
The dosage is gradually increased over four weeks, starting with one tablet in the morning and eventually reaching two tablets twice daily.
Side Effects:
Common side effects include nausea, constipation, and headache. Mood changes and sleep problems may also occur.
Considerations:
Contrave is not suitable for patients with uncontrolled hypertension, opioid use, or certain psychiatric conditions like bipolar disorder. Monitoring of kidney function, heart rate, and blood pressure may be required.
Average weight loss after 1 year: -6.1% vs -1.3% placebo (4.8%)
Cost:
Estimated cost: $250/month.
Phentermine (Duromine®)
Mechanism of Action:
Phentermine is a stimulant that acts on the brain’s appetite centers.
Dosage:
The usual dose is one capsule (15 mg or 30 mg) once a day in the morning. It is licensed for use for up to 3 months.
Side Effects:
Common side effects include increased heart rate, dry mouth, and sleeplessness.
Considerations:
Phentermine is not suitable for patients with high blood pressure, heart problems, or psychiatric conditions. It’s also contraindicated in cases of glaucoma, history of drug or alcohol misuse, and agitated states.
Cost:
Estimated cost: $100/month.
Liraglutide (Saxenda®)
Mechanism of Action:
Liraglutide, sold under the brand name Saxenda, is a GLP-1 receptor agonist that suppresses appetite. It also plays a role in glucose metabolism keeping blood sugar levels low.
Dosage:
The medication starts at a dose of 0.6 mg daily, with gradual increases each week until a target dose of 3.0 mg is reached. It is administered via subcutaneous injection.
Side Effects:
Common side effects include nausea, constipation, and diarrhea. There’s also a small increased risk of pancreatitis.
Considerations:
The medication is not suitable for patients with a history of certain thyroid cancers or multiple endocrine neoplasia type 2.
Average weight loss after 1 year: 8.6% vs 2.6% placebo (6%)
Cost:
Estimated cost: $500/month.
Semaglutide (Ozempic®)
Mechanism of Action:
Semaglutide is also a GLP-1 receptor agonist reducing feelings of hunger and blood sugar levels.
Dosage:
Semaglutide is a once-weekly injectable medication. The starting dose is 0.25mg injected once weekly for 4 weeks, then the dose is moved up to 0.5mg once weekly. After this the dose may be increased every 4 weeks up to 2mg once weekly depending on the response.
Side Effects:
Common side effects include nausea, vomiting, diarrhoea, abdominal pain and constipation.
Considerations and Cost:
Currently Semaglutide is very difficult to obtain in New Zealand. There is very high demand in especially the United States due to recent research showing strong efficacy. The result is that the cost to purchase is quite high. This medication is also not suitable for patients with a history of certain thyroid cancers or multiple endocrine neoplasia type 2.
The Reality of Weight Regain
It’s important to note that weight is likely to be regained once medications are stopped. This makes adherence to lifestyle modifications even more crucial. Obesity is a chronic disease influenced by genetics which is often activated by our current environment, requiring ongoing effort from you and your healthcare provider. For morbid obesity, surgical intervention often becomes the preferred method due to its long-term effectiveness. However, due to anaesthetic risks extreme weight may be considered too risky for undergoing surgical options.
Closing Words
While the journey of weight loss is challenging, the health benefits gained during the period of weight loss are substantial. Improvements in blood pressure, liver health, heart health, and sleep quality can be achieved with as little as a 5% reduction in body weight. Even if weight regain occurs, the benefits accrued during the weight loss period are not negated, making the effort worthwhile.
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