Recently the Endocrine Society provided recommendations for use of weight loss medications for treating obesity. Here is a summary of the Endocrine Society recommendations and a review of available medications for weight loss management in obese patients.
Medications for weight management should be combined with nutritional, physical activity, and behavioral therapies. Medications are used for management of underlying conditions, slowing progression of weight gain, and also improving the health and quality of life of patients who are overweight or obese.
The FDA indications for weight loss medications include patients with obesity (BMI greater or equal to 30 kg/m2), and patients who are overweight (BMI greater or equal to 27 kg/m2) with presence of complications such as type 2 diabetes mellitus, hypertension, or dyslipidemia. If weight loss is not adequate after 12 weeks of using one weight management medication the dose may be increased or alternative medications may be considered.
Weight loss medications treat other associated conditions and improve adherence to behavior changes. Associated conditions include high blood pressure, high cholesterol, type 2 diabetes mellitus, and obstructive sleep apnea. The benefits of weight loss include reduction of risk factors, improvements in feeling and function, and prevention of diseases.
The efficacy and safety of treatment should be assessed monthly for the first three months of weight management therapy, then every three months thereafter.
If a patient’s weight loss is 5% or more of body weight 3 months after starting a weight loss medication the medication should be continued. If a patient’s weight loss is less than 5% of body weight at 3 months after starting a weight loss medication the medication should be discontinued and alternative medications should be considered.
Sympathomimetic agents such as phentermine and diethylpropion are not recommended for obese patients with uncontrolled high blood pressure or history of heart disease who are candidates for weight management medications.
Non-sympathomimetics such as lorcaserin and/or orlistat are preferred for patients with heart disease.
ACE inhibitors, ARBs, and/or calcium channel blockers are preferred over beta-blockers as first-line therapy for patients with high blood pressure and type 2 diabetes mellitus.
Antidiabetic medications that promote weight loss are recommended for patients with type 2 diabetes. Examples include metformin, GLP-1 analogs (exenatide, liraglutide) or sodium-glucose-linked transporter-2 inhibitors (canagliflozin, empagliflozin).
Weight management drugs approved in 1999 or earlier
Sympathomimetic amines are stimulant agents that mimic the behaviors of neurotransmitters such as epinephrine, norepinephrine, dopamine, and catecholamines. These agents suppress appetite and increase satiety. Their adverse reactions include palpitations, tachycardia, increased blood pressure, over stimulation, tremor, dizziness, insomnia, dry mouth, headache, diarrhea, and constipation. They are contraindicated in patients with severe hypertension, pulmonary hypertension, hyperthyroidism, glaucoma, within 14 days of monoamine oxidase inhibitors (MAOI) therapy, and during pregnancy.
Examples of sympathomimetics:
Phentermine (Adipex P, Suprenza) is a schedule IV medication. The usual dose is up 15-37.5 mg/day. It should be taken before breakfast or 1-2 hours after breakfast. The average wholesale price (AWP) for 15 mg is $125.15, 30 mg is $118.78, and 37.5 mg is $157.00.
Diethylpropion (Tenuate, Dospan) is also a schedule IV medication. The recommended dose is 25 mg every 8 hours or 75 mg daily. The AWP for 100 tablets of 25 mg is $51.85 and for 75 mg it is $130.17.
Phendimetrazine (Bontril PDM) is a schedule III medication. The usual dose is 105 mg capsule once daily before breakfast or 17.5 to 35 mg tablets 2-3 times daily one hour before meals. The AWP for generic phendimetrazine 35 mg is $20.40 for 100 tablets. The cost of brand name Bontril PDM 35 mg is $101.83 for 100 tablets.
Benzphetamine (Didrex, Regimex) is a schedule III medication. The dose is adjusted based on individual response. The initial dose is 25 to 50 mg once daily, and the dose is titrated to 25 to 50 mg 1-3 times daily. The AWP for generic benzphetamine 50 mg is $131.07 for 100 tablets, and for brand name Didrex 50 mg it is $317.04 for 100 tablets.
Gastrointestinal lipase inhibitor
Gastrointestinal lipase inhibitor reversibly inhibits gastric and pancreatic lipase, thus reducing absorption of dietary fats by 30%. Its adverse reactions include headache, abdominal pain, fecal urgency, oily stool, back pain, upper respiratory infection, influenza, menstrual irregularities, nausea, urinary tract infection, myalgia, and otitis. It is contraindicated in patients with chronic malabsorption syndrome, cholestasis, and pregnancy.
Orlistat (Xenical, Alli [OTC]) is a lipase inhibitor used for obesity management. Xenical is a prescription form of orlistat. The recommended dose is 120 mg three times daily with each main meal containing fat. Alli is an over-the-counter formulation of orlistat. The recommended dose of Alli is 60 mg three times daily with each main meal containing fat. Its maximum dose is 180 mg daily. Orlistat decreases absorption of fat-soluble vitamins such as vitamins A, D, E, and K. The AWP for Alli 60 mg is $52.79 for 90 capsules and for Xenical 120 mg it is $563.80 for 90 capsules.
Weight management drugs approved 2012 and beyond
Belviq’s exact mechanism of action is not known. It reduces the feeling of hunger and need to consume food. Belviq activates serotonin 2C (5HT2C) receptors on pro-opiomelanocortin neurons. Pro-opiomelanocortin neurons are hormone precursors in the hypothalamus, a portion of the brain responsible for many functions including control of hunger. Activating these receptors causes satiety leading to less food consumption and ultimately weight loss. Essentially Belviq possibly decreases food consumption by making a person feel full even after consuming less food than usual.
Adverse Reactions of Belviq include dizziness, fatigue, nausea, dry mouth, constipation, cough, reduced heart rate, and hyperprolactinemia. It is contraindicated in people with defective heart valves, psychiatric disorders, serotonin syndrome or neuroleptic malignant syndrome, and pregnant patients
The recommended dose of Belviq is one 10 mg tablet twice a day by mouth with or without food. Learn more about Belviq.
Phentermine HCl/ topiramate ER (Qsymia)
Phentermine suppresses appetite by triggering the release of a brain chemical (hormone) called leptin, which regulates appetite. Topiramate causes weight loss by reducing appetite, increasing feelings of fullness, reducing the taste of food, and increasing burning of calories. Adverse reactions of Qsymia include increased heart rate, headache, insomnia, xerostomia, constipation, upper respiratory tract infection,dizziness, depression, and anxiety. It is contraindicated in patients with severe hyperthyroidism, glaucoma, within 14 days of MAOI therapy, and pregnancy.
The recommended dose of Qsymia is 3.75/23 mg (phentermine/topiramate) once daily for 14 days then increase dose to 7.5/46 mg once daily for 12 weeks then evaluate weight loss. If 3% of baseline body weight has not been lost discontinue use or increase dose to 11.25 mg/69 mg once daily for 14 days and then to 15/92 mg once daily.
Evaluate weight loss after 12 weeks of 15/92 mg and if 5% of baseline body weight has not been lost gradually discontinue therapy.
The cost for 30 capsules of Qsymia 3.75/23 mg is $198.24; Qsymia 7.5/46 mg is $204.78; Qsymia 11.25/69 mg is $239.40, and Qsymia 15/92 mg is $239.40. Learn more about Qysmia.
Naltrexone HCl/ bupropion HCl ER (Contrave)
Contrave is a combination of two FDA approved medications, naltrexone and bupropion. Naltrexone is an opioid antagonist approved for treatment of opioid and alcohol abuse. Prescription opioid medications include Percocet, Dilaudid, Oxycontin, Vicodin, and Norco. These medications are controlled substances because they have a high risk of abuse and dependence. Naltrexone works by blocking receptors these medications bind to in the body. When these receptors are blocked by naltrexone, opioids and alcohol are unable to bind to the receptor and produce their effects, reducing the effect of opioids and alcohol. Bupropion is approved for treatment of depression and smoking cessation. It stops chemicals in the brain called dopamine and norepinephrine from being taken up by neurons, keeping them active in the brain.
Contrave is a fixed dose combination of naltrexone and bupropion. How this combination works to cause weight loss is not known. Scientists think that Contrave may work on areas of the brain that control appetite and the reward system (the part of the brain that remembers a rewarding experience in order to repeat it).
The three most common side effects of Contrave are nausea, constipation, and headache. Other side effects of Contrave include vomiting, dizziness, insomnia, dry mouth, and diarrhea. It is contraindicated in patients with uncontrolled hypertension,seizure disorders, anorexia nervosa or bulimia, or undergoing abrupt discontinuation of alcohol, benzodiazepines, barbiturates, and antiepileptic drugs. It should not be used in combination with bupropion-containing products, within 14 days of MAOI use, and in combination with chronic opioid medications.
Contrave is only available as an extended release tablet containing 8 mg of naltrexone and 90 mg of bupropion. The manufacturer recommends slowly increasing the dose of Contrave over a 1-month period. During the first week, Contrave should be administered as 1 tablet every morning. In the second week increase the dose to 1 tablet in the morning and 1 tablet in the evening. For week three, increase to 2 tablets in the morning and 1 tablet in the evening. During the final week, give 2 tablets in the morning and 2 tablets in the evening. This provides a total daily dose of 32 mg of naltrexone and 360 mg of bupropion which is the maximum recommended daily dose of Contrave. Learn more about Contrave.
Saxenda belongs to a group of drugs known as glucagon-like peptide-1 (GLP-1) receptor agonists because they resemble and mimic the action of human GLP-1 hormone (incretin hormone). They are also known as incretin mimetics. It is a higher dose of Victoza which is used for treating type 2 diabetes. Saxenda controls appetite by reducing the feeling of hunger. It also delays the emptying of food from the stomach and increases the feeling of fullness. This results in weight loss.
Common side effects of Saxenda include nausea, hypoglycemia, diarrhea, constipation, vomiting, headache, decreased appetite, dyspepsia, fatigue, dizziness, abdominal pain, and increased lipase. The risk of hypoglycemia (low blood glucose) is increased in diabetics taking a sulfonylurea. Serious side effects of Saxenda include pancreatitis, reduced kidney function, gallbladder disease, and suicidal thoughts. Saxenda causes thyroid C-cell tumors at clinically relevant exposures in rats and mice. It is unknown whether Saxenda causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC) in humans. It should not be used in patients with a personal or family history of MTC or in patients with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).Saxenda is contraindicated in patients with personal or a family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2. It is also contraindicated in pregnant women.
The recommended dose of Saxenda is 3 mg subcutaneous injection daily. Patients should initiate at 0.6 mg per day for one week, and increase the dose weekly until a dose of 3 mg is reached. The cost of Saxenda is expected to be about $9000 a year. Learn more about Saxenda.
Seger JC, Horn DB, Westman EC, Primack C, Schmidt SL, Ravasia D, McCarthy W, Ferguson U, Sabowitz BN, Scinta W, Bays HE. Obesity Algorithm, presented by the American Society of Bariatric Physicians. 2014 - 2015 www.obesityalgorithm.org (Accessed 2/2015)
Pharmacological Management of Obesity: An Endocrine Society Clinical Practice Guideline