Anti-obesity medication or weight loss drugs are pharmacological agents that reduce or control weight. These drugs alter one of the fundamental processes of the human body, weight regulation, by altering either appetite, or absorption of calories. The main treatment modalities for overweight and obese individuals remain dieting and physical exercise.
In the United States orlistat (Xenical) is currently approved by the FDA for long-term use. It reduces intestinal fat absorption by inhibiting pancreatic lipase. Rimonabant (Acomplia), a second drug, works via a specific blockade of the endocannabinoid system. It has been developed from the knowledge that cannabis smokers often experience hunger, which is often referred to as "the munchies". It had been approved in Europe for the treatment of obesity but has not received approval in the United States or Canada due to safety concerns. The European Medicines Agency in October 2008 recommended the suspension of the sale of rimonabant as the risks seem to be greater than the benefits. Sibutramine (Meridia), which acts in the brain to inhibit deactivation of the neurotransmitters, thereby decreasing appetite was withdrawn from the United States and Canadian markets in October 2010 due to cardiovascular concerns.
Because of potential side effects, and limited evidence of small benefits in weight reduction especially in obese children and adolescents, it is recommended that anti-obesity drugs only be prescribed for obesity where it is hoped that the benefits of the treatment outweigh its risks.
- 1 Mechanisms of action
- 2 History
- 3 Medication
- 4 Herbal and alternative medicine
- 5 Side effects
- 6 Research
- 7 See also
- 8 References
- 9 Further reading
- 10 External links
Mechanisms of action
Current and potential anti-obesity drugs may operate through one or more of the following mechanisms:
- Catecholamine releasing agents such as amphetamine, phentermine, and related substituted amphetamines (e.g., bupropion) which act as appetite suppressants are the main tools used for the treatment of obesity.
- Increase of the body's metabolism.
- Interference with the body's ability to absorb specific nutrients in food. For example, Orlistat (also known as Xenical and Alli) blocks fat breakdown and thereby prevents fat absorption. The OTC fiber supplements glucomannan and guar gum have been used for the purpose of inhibiting digestion and lowering caloric absorption
Anorectics are primarily intended to suppress the appetite, but most of the drugs in this class also act as stimulants (e.g., amphetamine), and patients have abused drugs "off label" to suppress appetite (e.g. digoxin).
The first described attempts at producing weight loss are those of Soranus of Ephesus, a Greek physician, in the second century AD. He prescribed elixirs of laxatives and purgatives, as well as heat, massage, and exercise. This remained the mainstay of treatment for well over a thousand years. It was not until the 1920s and 1930s that new treatments began to appear. Based on its effectiveness for hypothyroidism, thyroid hormone became a popular treatment for obesity in euthyroid people. It had a modest effect but produced the symptoms of hyperthyroidism as a side effect, such as palpitations and difficulty sleeping. 2,4-Dinitrophenol (DNP) was introduced in 1933; this worked by uncoupling the biological process of oxidative phosphorylation in mitochondria, causing them to produce heat instead of ATP. The most significant side effect was a sensation of warmth, frequently with sweating. Overdose, although rare, lead to a rise in body temperature and, ultimately, fatal hyperthermia. By the end of 1938 DNP had fallen out of use because the FDA had become empowered to put pressure on manufacturers, who voluntarily withdrew it from the market.
Amphetamines (marketed as Benzedrine) became popular for weight loss during the late 1930s. They worked primarily by suppressing appetite, and had other beneficial effects such as increased alertness. Use of amphetamines increased over the subsequent decades, including Obetrol and culminating in the "rainbow pill" regime. This was a combination of multiple pills, all thought to help with weight loss, taken throughout the day. Typical regimens included stimulants, such as amphetamines, as well as thyroid hormone, diuretics, digitalis, laxatives, and often a barbiturate to suppress the side effects of the stimulants. In 1967/1968 a number of deaths attributed to diet pills triggered a Senate investigation and the gradual implementation of greater restrictions on the market.
Meanwhile, phentermine had been FDA approved in 1959 and fenfluramine in 1973. The two were no more popular than other drugs until in 1992 a researcher reported that when combined the two caused a 10% weight loss which was maintained for more than two years. Fen-phen was born and rapidly became the most commonly prescribed diet medication. Dexfenfluramine (Redux) was developed in the mid-1990s as an alternative to fenfluramine with fewer side-effects, and received regulatory approval in 1996. However, this coincided with mounting evidence that the combination could cause valvular heart disease in up to 30% of those who had taken it, leading to withdrawal of Fen-phen and dexfenfluramine from the market in September 1997.
Some patients find that diet and exercise is not a viable option; for these patients, anti-obesity drugs can be a last resort. Some prescription weight loss drugs are stimulants, which are recommended only for short-term use, and thus are of limited usefulness for extremely obese patients, who may need to reduce weight over months or years.
Orlistat (Xenical) reduces intestinal fat absorption by inhibiting pancreatic lipase. Some side-effects of using Orlistat include frequent, oily bowel movements (steatorrhea). But if fat in the diet is reduced, symptoms often improve. Originally available only by prescription, it was approved by the FDA for over-the-counter sale in February 2007. On 26 May 2010, the U.S. Food and Drug Administration (FDA) has approved a revised label for Xenical to include new safety information about cases of severe liver injury that have been reported rarely with the use of this medication. Of the 40 million users of Orlistat worldwide, 13 cases of severe liver damage have been reported.
Lorcaserin (Belviq) was approved June 28, 2012 for obesity with other co-morbidities. The average weight loss by study participants was modest,[vague] but the most common side effects of the medication are considered benign. It reduces appetite by activating a type of serotonin receptor known as the 5-HT2C receptor in a region of the brain called the hypothalamus, which is known to control appetite.
Sibutramine (Reductil or Meridia) is an anorectic or appetite suppressant, reducing the desire to eat. Sibutramine may increase blood pressure and may cause dry mouth, constipation, headache, and insomnia.
In the past, it was noted by the US that Meridia was a harmless drug for fighting obesity. The US District Court of the Northern District of Ohio rejected 113 cases complaining about the negative effects of the drug, stating that the clients lacked supporting facts and that the representatives involved were not qualified enough.
Sibutramine has been withdrawn from the market in the United States, the UK, the EU, Australia, Canada, Hong Kong and Colombia. Its risks (non-life-threatening myocardial infarction and stroke) have been shown to outweigh the benefits.
Rimonabant (also known as SR141716; trade names Acomplia and Zimulti) was an anorectic antiobesity drug that was first approved in Europe in 2006 but was withdrawn worldwide in 2008 due to serious psychiatric side effects; it was never approved in the United States. Rimonabant is an inverse agonist for the cannabinoid receptor CB1 and was the first drug approved in that class.
In people with Diabetes mellitus type 2, the drug metformin (Glucophage) can reduce weight. Metformin limits the amount of glucose that is produced by the liver as well as increases muscle consumption of glucose. It also helps in increasing the body's response to insulin.
Exenatide (Byetta) is a long-acting analogue of the hormone GLP-1, which the intestines secrete in response to the presence of food. Among other effects, GLP-1 delays gastric emptying and promotes a feeling of satiety. Some obese people are deficient in GLP-1, and dieting reduces GLP-1 further. Byetta is currently available as a treatment for Diabetes mellitus type 2. Some, but not all, patients find that they lose substantial weight when taking Byetta. Drawbacks of Byetta include that it must be injected subcutaneously twice daily, and that it causes severe nausea in some patients, especially when therapy is initiated. Byetta is recommended only for patients with Type 2 Diabetes. A somewhat similar drug, Symlin, is currently available for treating diabetes and is in testing for treating obesity in non-diabetics.
Liraglutide (Saxenda) is another GLP-1 analogue.
The combination of phentermine and topiramate, brand name Qsymia (formerly Qnexa) was approved by the U.S. FDA on July 17, 2012, as an obesity treatment complementary to a diet and exercise regimen. The European Medicines Agency, by contrast, rejected the combination as a treatment for obesity, citing concerns about long-term effects on the heart and blood vessels, mental health and cognitive side-effects.
Bupropion/naltrexone is a combination drug used for weight loss in those that are either obese or overweight with some weight-related illnesses It combines low doses of bupropion and naltrexone. Both drugs have individually shown some evidence of effectiveness in weight loss, and the combination has been shown to have some synergistic effects on weight. In September 2014, a sustained release formulation of the drug was approved for marketing in the United States under the brand name Contrave. The combination was subsequently approved in the European Union in the spring of 2015, where it will be sold under the name Mysimba.
Other weight loss drugs have also been associated with medical complications, such as fatal pulmonary hypertension and heart valve damage due to Redux and Fen-phen, and hemorrhagic stroke due phenylpropanolamine. Many of these substances are related to amphetamine.
Tesofensine (NS2330) is a serotonin–noradrenaline–dopamine reuptake inhibitor from the phenyltropane family of drugs, which is being developed for the treatment of obesity. Tesofensine was originally developed by a Danish biotechnology company, NeuroSearch, who transferred the rights to Saniona in 2014. Tesofensine has been evaluated in Phase 1 and Phase 2 human clinical studies with the aim of investigating treatment potential with regards to obesity.
Unresearched nonprescription products or programs for weight loss are heavily promoted by mail and print advertising and on the internet. The US Food and Drug Administration recommends caution with use of these products, since many of the claims of safety and effectiveness are unsubstantiated. Individuals with anorexia nervosa and some athletes try to control body weight with laxatives, diet pills or diuretic drugs, although these generally have no impact on body fat. Products that work as a laxative can cause the blood's potassium level to drop, which may cause heart and/or muscle problems. Pyruvate is a popular product that may result in a small amount of weight loss. However, pyruvate, which is found in red apples, cheese, and red wine, has not been thoroughly studied and its weight loss potential has not been scientifically established.
Herbal and alternative medicine
The ECA Stack cannot be marketed in most developed countries but used to be marketed as a weight loss; it provided modest short term weight loss but was ineffective in the long term and had adverse effects on the cardiovascular, mental, digestive, and nervous systems.
Some anti-obesity drugs can have severe, even, lethal side effects, fen-phen being a famous example. Fen-phen was reported through the FDA to cause abnormal echocardiograms, heart valve problems, and rare valvular diseases. One of, if not the first, to sound alarms was Sir Arthur MacNalty, Chief Medical Officer (United Kingdom). As early as the 1930s, he warned against the use of dinitrophenol as an anti-obesity medication and the injudicious and/or medically unsupervised use of thyroid hormone to achieve weight reduction. The side effects are often associated with the medication's mechanism of action. In general, stimulants carry a risk of high blood pressure, faster heart rate, palpitations, closed-angle glaucoma, drug addiction, restlessness, agitation, and insomnia.
Another drug, orlistat, blocks absorption of dietary fats, and as a result may cause oily spotting bowel movements (steatorrhea), oily stools, stomach pain, and flatulence. A similar medication designed for patients with Type 2 diabetes is Acarbose; which partially blocks absorption of carbohydrates in the small intestine, and produces similar side effects including stomach pain and flatulence.
Other classes of drugs in development include lipase inhibitors, similar to orlistat. Another lipase inhibitor, called GT 389-255, was being developed by Peptimmune (licensed from Genzyme). This was a novel combination of an inhibitor and a polymer designed to bind the undigested triglycerides therefore allowing increased fat expulsion without side effects such as oily stools that occur with orlistat. The development stalled as Phase 1 trials were conducted in 2004 and there was no further human clinical development afterward. In 2011, Peptimmune filed for Chapter 7 Liquidation.
- National Institute for Health and Clinical Excellence. Clinical guideline 43: Obesity: The prevention, identification, assessment and management of overweight and obesity in adults and children. London, 2006.
- "WIN – Publication – Prescription Medications for the Treatment of Obesity". National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). National Institutes of Health. Archived from the original on 13 January 2009. Retrieved 14 January 2009.
- "Anti-obesity drug no magic bullet". Canadian Broadcasting Corporation. 2 January 2007. Retrieved 19 September 2008.
- "FDA Briefing Document NDA 21-888 Zimulti (rimonabant) Tablets, 20 mg Sanofi Aventis Advisory Committee" (PDF). Food and Drug Administration. 13 June 2007. Archived (PDF) from the original on 10 September 2008. Retrieved 19 September 2008.
- "Nutrition Police".
- "Abbott Laboratories Voluntarily Withdraws Weight-loss Drug Sibutramine (Meridia) from the Canadian Market – Health Canada Information Update 2010-10-08".
- Mead, E; Atkinson, G; Richter, B; Metzendorf, MI; Baur, L; Finer, N; Corpeleijn, E; O'Malley, C; Ells, LJ (29 November 2016). "Drug interventions for the treatment of obesity in children and adolescents". The Cochrane database of systematic reviews. 11: CD012436. PMID 27899001.
- Snow V, Barry P, Fitterman N, Qaseem A, Weiss K (2005). "Pharmacologic and surgical management of obesity in primary care: a clinical practice guideline from the American College of Physicians". Ann. Intern. Med. 142 (7): 525–31. doi:10.7326/0003-4819-142-7-200504050-00011. PMID 15809464.
- Cooke D, Bloom S (2006). "The obesity pipeline: current strategies in the development of anti-obesity drugs". Nature Reviews. Drug Discovery. 5 (11): 919–31. doi:10.1038/nrd2136. PMID 17080028.
- "Evekeo Prescribing Information" (PDF). Arbor Pharmaceuticals LLC. April 2014. pp. 1–2. Retrieved 11 August 2015.
- Bray, G. A. (1993). "Use and Abuse of Appetite-Suppressant Drugs in the Treatment of Obesity". Annals of Internal Medicine. 119 (7, Pt. 2): 707–713. doi:10.7326/0003-4819-119-7_Part_2-199310011-00016.
- Parascandola J (November 1974). "Dinitrophenol and bioenergetics: an historical perspective". Mol. Cell. Biochem. 5 (1–2): 69–77. doi:10.1007/BF01874175. PMID 4610359.
- Pool, Robert (2001). Fat: Fighting the Obesity Epidemic. Oxford, UK: Oxford University Press. ISBN 0-19-511853-7.
- Weintraub M (May 1992). "Long-term weight control: The National Heart, Lung, and Blood Institute funded multimodal intervention study". Clin. Pharmacol. Ther. 51 (5): 581–5. doi:10.1038/clpt.1992.68. PMID 1445528.
- Kolata, Gina (2007). Rethinking thin: The new science of weight loss – and the myths and realities of dieting. Picador. ISBN 0-312-42785-9.
- "Obesity Medication".
- "Press Announcements". fda.gov.
- "FDA Drug Safety Communication: Completed safety review of Xenical/Alli (orlistat) and severe liver injury". fda.gov.
- Aronne, L.J.; Powell, A.G.; Apovian, C.M. (2011). "Emerging pharmacotherapy for obesity". Expert Opinion on Emerging Drugs. 16 (3): 587–96. doi:10.1517/14728214.2011.609168. PMID 21834735.
- Bray, GA; Frühbeck, G; Ryan, DH; Wilding, JP (7 May 2016). "Management of obesity". Lancet. 387 (10031): 1947–56. doi:10.1016/S0140-6736(16)00271-3. PMID 26868660.
- Shukla, AP; Kumar, RB; Aronne, LJ (2015). "Lorcaserin Hcl for the treatment of obesity". Expert Opinion on Pharmacotherapy. 16 (16): 2531–8. doi:10.1517/14656566.2015.1096345. PMID 26472579.
- Obesity, Fitness & Wellness Week (14 August 2004). "Legal Issues; Court dismisses claims against anti-obesity medication". Retrieved 9 April 2012.
- Rockoff, Jonathan D.; Dooren, Jennifer Corbett (8 October 2010). "Abbott Pulls Diet Drug Meridia Off US Shelves". The Wall Street Journal. Archived from the original on 11 October 2010. Retrieved 8 October 2010.
- "Top obesity drug sibutramine being suspended". BBC News. 22 January 2010. Archived from the original on 25 January 2010. Retrieved 22 January 2010.
- (in German) Sibutramin-Vertrieb in der Europäischen Union ausgesetzt . Abbott Laboratories in Germany. Press Release 2010-01-21. Retrieved 2010-01-27
- "Sibutramine (brand name Reductil) Information – Australia". Abbott Laboratories. 2010. Archived from the original on 14 October 2010. Retrieved 8 October 2010.
- "MedEffect Canada - Advisories, Warnings and Recalls - Health Canada". hc-sc.gc.ca.
- "De-registration of pharmaceutical products containing sibutramine" (Press release). info.gov in Hong Kong. 2 November 2010. Retrieved 8 November 2010.
- "Top 10 Diet Pills That Work in 2014". TENMANIA. 2014. Retrieved April 15, 2014.
- "Rimonabant". AdisInsight. Retrieved 21 February 2017.
- Sam, AH; Salem, V; Ghatei, MA (2011). "Rimonabant: From RIO to Ban". Journal of obesity. 2011: 432607. PMC . PMID 21773005.
- Moreira, FA; Crippa, JA (June 2009). "The psychiatric side-effects of rimonabant". Revista brasileira de psiquiatria (Sao Paulo, Brazil : 1999). 31 (2): 145–53. PMID 19578688.
- Fong TM, Heymsfield SB (September 2009). "Cannabinoid-1 receptor inverse agonists: current understanding of mechanism of action and unanswered questions". Int J Obes (Lond). 33 (9): 947–55. doi:10.1038/ijo.2009.132. PMID 19597516.
- "European Approval Comes Early for Sanofi-Aventis' Acomplia". IHS. June 23, 2006.
- George A. Bray; Frank L. Greenway (1999). "Current and Potential Drugs for Treatment of Obesity: Table 19: Clinical trials with metformin for the treatment of obese diabetics". Endocrine Reviews. 20 (6): 805–87. doi:10.1210/er.20.6.805. PMID 10605627. Archived from the original on 15 October 2007. Retrieved 7 August 2006.
- "Diabetes Medications: Metformin" (PDF). Archived from the original (PDF) on 8 July 2015. Retrieved 21 October 2015.
- de Luis DA, Gonzalez Sagrado M, Conde R, Aller R, Izaola O (2007). "Decreased basal levels of glucagon-like peptide-1 after weight loss in obese subjects". Ann. Nutr. Metab. 51 (2): 134–8. doi:10.1159/000103273. PMID 17536190.
- Sauer, N; Reining, F; Schulze Zur Wiesch, C; Burkhardt, T; Aberle, J (July 2015). "Off-label antiobesity treatment in patients without diabetes with GLP-1 agonists in clinical practice". Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme. 47 (8): 560–4. doi:10.1055/s-0034-1387793. PMID 25230325.
- Salynn Boyles (2012-07-17). "FDA approves diet drug Qsymia : agency warns of increased risk for oral birth defects". WebMD., citing "FDA approves weight-management drug Qsymia" (Press release). U.S. Food and Drug Administration. 2012-07-17.
- Abenhaim L; Moride Y; Brenot F; et al. (August 1996). "Appetite-suppressant drugs and the risk of primary pulmonary hypertension. International Primary Pulmonary Hypertension Study Group". N. Engl. J. Med. 335 (9): 609–16. doi:10.1056/NEJM199608293350901. PMID 8692238.
- Alfred P. Fishman, MD (1999). "Aminorex to Fen/Phen: An Epidemic Foretold". Circulation. 99 (1): 156–161. doi:10.1161/01.CIR.99.1.156. PMID 9884392. Retrieved 24 July 2006.
- Doggrell, SA (2009). "Tesofensine--a novel potent weight loss medicine. Evaluation of: Astrup A, Breum L, Jensen TJ, Kroustrup JP, Larsen TM. Effect of tesofensine on bodyweight loss, body composition, and quality of life in obese patients: a randomised, double-blind, placebo-controlled trial. Lancet 2008;372:1906-13". Expert Opin Investig Drugs. 18 (7): 1043–6. doi:10.1517/13543780902967632. PMID 19548858.
- https://newsclient.omxgroup.com/cdsPublic/viewDisclosure.action?disclosureId=630243&messageId=782165. Missing or empty
- U.S. Food and Drug Administration: The Facts About Weight Loss Products and Programs Archived 11 August 2007 at the Wayback Machine.
- "Prepared Statement of the Federal Trade Commission on the Marketing of Dietary Supplements" (Press release). Committee on Governmental Affairs, United States Senate. 8 October 2002. Archived from the original on 25 August 2006. Retrieved 7 August 2006.
- Martin M, Schlabach G, Shibinski K (1998). "The Use of Nonprescription Weight Loss Products Among Female Basketball, Softball, and Volleyball Athletes from NCAA Division I Institutions: Issues and Concerns". J Athl Train. 33 (1): 41–44. PMC . PMID 16558483.
- George A. Bray; Frank L. Greenway (1999). "Current and Potential Drugs for Treatment of Obesity: Postabsorptive modifiers of nutrient metabolism". Endocrine Reviews. 20 (6): 805–87. doi:10.1210/er.20.6.805. PMID 10605627.
- Lau DC, Douketis JD, Morrison KM, Hramiak IM, Sharma AM, Ur E (April 2007). "2006 Canadian clinical practice guidelines on the management and prevention of obesity in adults and children [summary]". CMAJ. 176 (8): S1–13. doi:10.1503/cmaj.061409. PMC . PMID 17420481.
- Onakpoya IJ, Posadzki PP, Watson LK, Davies LA, Ernst E (March 2012). "The efficacy of long-term conjugated linoleic acid (CLA) supplementation on body composition in overweight and obese individuals: a systematic review and meta-analysis of randomized clinical trials". Eur J Nutr (Systematic review). 51 (2): 127–34. doi:10.1007/s00394-011-0253-9. PMID 21990002.
- Shekelle PG, Hardy ML, Morton SC, et al. (March 2003). "Efficacy and safety of ephedra and ephedrine for weight loss and athletic performance: a meta-analysis". JAMA. 289 (12): 1537–45. doi:10.1001/jama.289.12.1537. PMID 12672771.
- Bachorik, Lawrence. "FDA Announces Withdrawal Fenfluramine and Dexfenfluramine (Fen-Phen)". U.S. Food and Drug Administration. FDA. Retrieved 2014-01-27.
- , Launceston, Tasmania, Australia, Examiner, Friday, January 21, 1938, p 14, which states in postscript "However, the sex which for many years injured its health by tight lacing is not likely to be deterred from slimming by such considerations, The dictates of fashion will be paramount." Sir Arthur was particularly concerned with the neurological side effects of the then popular practice of dosing with thyroid extract to lose weight and, also, use of the then much vaunted weight loss drug dinitrophenol, which his report found killed as many patients as it reduced in girth, as well as, the compromise of the malnourished’s immune system and their consequent, often, inability to resist infectious diseases like the then endemic tuberculosis (archaic "epidemics of consumption").
- See, also, , Sidney Morning Herald, Nov. 17, 1937, p 10.
- Johnson, Kimball. "Alli: A Weight Loss Drug". WebMD. WebMD. Retrieved 2014-01-27.
- "acarbose - oral, Precose". MedicineNet. MedicineNet. Retrieved 2014-01-27.
- "Peptimmune homepage". peptimmune.com.
- McBride, Ryan. "Genzyme-Spinout Peptimmune Files for Chapter 7 Liquidation". Xconomy Boston. Retrieved 5 September 2011.