Obesity is a chronic condition just like any other. It needs to have the proper medical attention and support in order to properly and effectively treat it. Some patients may even require surgery or medications in order to make their weight loss journey easier or more sustainable. Some specifically-approved prescription medications that are used can reduce the amount of energy absorbed from food. Others can reduce the desire to eat by causing the body to feel full. All of the prescription medications mentioned are for patient over a specific age. This age depends on each drug.
Orlistat is a drug that reduces the amount of fat absorbed from the food eaten. Fats that are typically eaten need to be broken down in order for the body to absorb them. This specific drug blocks the enzyme that breaks them down therefore restricting them from being absorbed. When using Orlistat, it is important to keep in mind that this drug does not block other enzymes used to break down other macros, such as proteins or carbs. Therefore, a patient using Orlistat still needs to be mindful of their carb consuming.
Another approved weightloss medication is called Lorcaserin, whose branded version is known as Belviq. Serotonin is a hormone that is secreted by the intestines to decrease appetite when eating. When the individual is not consuming food, the receptors’ need for this hormone can lead to cravings. Lorcaserin attaches to serotonin receptors in order to create a feeling of fullness and lower cravings. It not only attaches to the receptor but invokes the same feeling just as a key fits a lock and opens it as shown in the diagram below.
Lock-and-key hypothesis, Brookhaven National Laboratory
Phentermine-topiramate is a combination of medications that can be prescribed separately. Phentermine decreases your appetite because it is a sympathomimetic amine. It acts on the body stimulating the sympathetic nervous system which is responsible for your “fight-or-flight” response. Topiramate is generally used to treat seizures or migraine headaches but can also be used for weightloss because it reduces the activity of neurotransmitters at some GABA receptors as well as blocks a subtype of a glutamate receptor. Both these receptors are associated with appetite regulation and stimulation of these receptors is associated with feeding. Therefore, reducing stimulation of and activity at these receptors can decrease a patient’s appetite. When taken together these medications allow for a decreased consumption of food by causing an earlier feeling of fullness.
Naltrexone-bupropion is another combination medication. Naltrexone is used typically used to treat alcohol and drug dependence by working as an opiate antagonist. It reduces the desire to take drugs by inhibiting the feelings of well-being and pain relief that come with taking drugs. It is used in weightloss by inhibiting the feelings of well-being that can come from bingeing on carbohydrate-rich, high-sugar foods. Bupropion is used to help treat depression or get people to quit smoking by balancing the dopamine and epinephrine levels in your brain. Together these drugs can be used to decrease hunger and increase feelings of fullness.
Liraglutide is a medication that is used to create a decreased craving for food. This drug decreases the speed of gastric emptying, so the food remains in your stomach for a longer period of time, creating a feeling of fullness. This decreases the amount of food consumed allowing for burning of body fat.
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Phentermine - FDA prescribing information, side effects and uses. (n.d.). Retrieved from https://www.drugs.com/pro/phentermine.html#s-34089-3.
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Topiramate - FDA prescribing information, side effects and uses. (n.d.). Retrieved from https://www.drugs.com/pro/topiramate.html#s-34090-1.