Prescription Weight Loss Medications
Obesity is the largest and fastest growing public health problem all over the world. It results in a number of chronic diseases such as type 2 diabetes, osteoarthritis, obstructive sleep apnea, gallstones, and fatty liver diseases. Lifestyle modifications, such as diet and exercise are essential for both prevention and management of obesity. But if they are ineffective, prescription weight loss medications can be considered as one of the options.
In the past several years, many medications have been used to manage obesity. However, most of the anti-obesity drugs that were approved and marketed have been withdrawn due to serious adverse effects. Fenfluramine and dexfluramine were pulled out of the market in 1997 as they were linked to cardiac valvulopathy (an abnormal thickening of the valves of the heart) in patients when taken with phentermine (combination known as fen-phen). Phentermine is still available in the market. It is an appetite suppressant drug used for short-term (up to three months) treatment of obesity.
Other drugs such as rimonabant (Acomplia®) and sibutramine (Merida®) were withdrawn in 2008 and 2010 respectively, as they were linked to suicidal thoughts, depression, heart attack, and stroke.
Orlistat (Marketed under the trade name of Xenical® and Alli®)
Orlistat was approved in 1998 for the long-term management of obesity. It is marketed as a prescription under the trade name Xenical® (120 mg) in most of the countries and is sold over-the-counter as Alli® (60 mg) mainly in the United States.
When you eat fat containing food, your body breaks it down into its simplest components with the help of an enzyme called lipase to make it easily digestible. But if you consume food having excessive amount of calories, it is stored in the body in the form of fat, which results in weight gain. Orlistat works by blocking the enzyme lipase, thereby disabling the breakdown of fat. The undigested fat is eliminated out with your stools. This helps in shedding off the excess weight.
Consult your physician immediately if you develop itching, yellow eyes or skin, dark urine, loss of appetite, or light-colored stools. These may be the signs of liver injury. Recently, serious liver injury has been reported by the use of these drugs. FDA has added the warning of severe liver injury on labels of Xenical® and Alli® to educate the public regarding the signs and symptoms of liver injury.
It is prescribed with low calorie diet and exercise to help people in reducing weight effectively. Patients are advised to take a multivitamin at least 2 hours before or after taking orlistat as it reduces the absorption of some vitamins.
Phentermine (Marketed under the trade name of Adipex-P®)
How it works?
Phentermine is the most commonly prescribed weight loss medication for short-term use i.e. up to three months. It works by triggering the hunger channels present in the brain. It further raises the blood concentration of leptin (an appetite-regulating hormone), which reduces your appetite and makes you feel less hungry. For effective weight loss, it must be taken in conjugation with diet, exercise, and behavioral modification.
Side Effects: Consult your physician if you suffer from any of the following symptoms:
- Dry mouth
- Chest pain
- Decreased ability to exercise
- Swelling of feet or lower legs
- Trouble in breathing
NOTE: Phentermine is not recommended for long-term treatment of obesity due to its strong potential for abuse and dependence.
Lorcaserin (Marketed under the trade name of Belviq®)
How it works?
Belviq® is the first anti-obesity drug to be approved in the past 13 years. It works by activating specific receptors in the brain (i.e. serotonin receptors), which increase serotonin levels that control your appetite. This helps in decreasing your hunger and makes you feel full.
Belviq® is a 10 mg tablet taken twice a day and it should be discontinued if you are not able to lose 5 percent of your weight after 12 weeks of treatment.
Headaches, dizziness, fatigue, nausea, dry mouth, and constipation are the common side effects. But if you are having any suicidal thoughts and face any problem in retaining memory then you should consult your physician immediately.