Overview of Weight Loss Medications
Weight loss medications have been a common topic recently. This is likely because there has been an expansion of FDA-approved weight loss medications available to those struggling with excess weight.
Who can use weight loss medications?
Weight loss medications are FDA-approved for patients with obesity, defined as a BMI > 30kg/m2, or for patients with overweight and the presence of another weight-related condition such as type 2 diabetes mellitus, high blood pressure, or high cholesterol.
Do weight loss medications work?
Some medications can reduce body weight more than others. However, this is not the only thing considered when selecting the best weight loss medication. Other medical conditions, potential side effects, and patient preferences are all considered. Let’s review the types of medications available, their mechanisms of action, benefits, and possible side effects.
GLP-1 Agonists
GLP-1 agonists, including semaglutide and liraglutide, can promote feelings of fullness, slow stomach emptying, and significantly aid in weight management. These hormones also help regulate blood glucose and insulin levels and are used in diabetes care. Contraindications include a personal or family history of medullary thyroid carcinoma or a rare condition called Multiple Endocrine Neoplasia Syndrome Type 2. Gastrointestinal side effects are common and can include nausea, vomiting, diarrhea, and constipation.
Tirzepatide:
Tirzepatide is a GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) hormone receptor agonist. The mechanism of action, contraindications, and side effects are similar to those of GLP-1 agonists.
Phentermine:
Phentermine is a short-term weight loss medication that acts as an appetite suppressant. It stimulates the release of neurotransmitters in the brain, affecting hunger signals. On average, patients will experience a 5% weight reduction. There are numerous contraindications for this medication, such as a history of cardiovascular disease, hyperthyroidism, and glaucoma.
Orlistat:
Orlistat inhibits an enzyme called lipase that works to break down fats. This inhibits the absorption of dietary fats in the intestines, leading to reduced calorie intake. Orlistat is available both over-the-counter (Alli) and in prescription strength (Xenical). Common side effects include gastrointestinal issues such as oily stools and flatulence. Orlistat can also impair the ability to absorb fat-soluble vitamins such as Vitamin E and Vitamin K.
Naltrexone-Bupropion:
This combination medication consists of naltrexone, an opioid receptor antagonist, and bupropion, an antidepressant. One of the ways it works is to decrease food cravings. Side effects may include nausea, constipation, and headache. Naltrexone-Bupropion also has many contraindications, including uncontrolled hypertension, seizure disorder, or current or chronic use of opioids.
Phentermine HCl / Topiramate:
This combination medication consists of phentermine combined with topiramate, which is a medication that is also used to treat seizures and migraine headaches. The use of topiramate is contraindicated in pregnancy or for women who may become pregnant. Common side effects include changes in taste, constipation, and dry mouth.
Nonsystemic Oral Hydrogel:
Oral non-systemic superabsorbent hydrogels contain particles approximately the size of a grain of salt which then dissolve in the stomach, where they can then hydrate up to 100 times their original weight and promote fullness. They must be taken with at least 16 ounces of water 20 minutes before a meal. GI side effects are common, including discomfort, constipation, diarrhea, and nausea.
Should I take weight loss medication?
As noted above, many factors must be considered when starting a weight loss medication, and this discussion should occur with your doctor. In any case, while weight loss medications can be valuable tools in achieving and maintaining weight loss, they are most effective when combined with lifestyle changes, including a healthy diet, regular physical activity, quality sleep, and stress management.
*References available with PDF download