Orlistat-Induced Systemic Adverse Events: A Review of Case Reports And Public Health Implications

Year 2025, Volume: 3 Issue: 3, 110 - 120, 15.01.2026

Murat Kösedağ

https://doi.org/10.62425/rtpharma.1770239

Abstract

Orlistat is a widely used gastrointestinal lipase inhibitor for obesity management. While its efficacy and safety are established under medical supervision, increasing unsupervised use has raised concerns regarding serious adverse events. This review aims to alert healthcare providers to the potential for significant adverse effects associated with Orlistat by synthesizing a collection of reported clinical cases. The review includes literature published between January 1988 and March 2025. We present case reports highlighting a range of adverse effects, including acute pancreatitis, hepatotoxicity, and acute oxalate nephropathy. These conditions are often linked to patient-specific vulnerabilities, pre-existing health conditions, or misuse, particularly among individuals with eating disorders. This review underscores the importance of careful patient selection, close monitoring, and increased awareness among family physicians, pharmacists, and other healthcare providers to ensure the safe use of Orlistat. When appropriately prescribed and monitored, Orlistat remains a valuable tool in obesity management. However, its unsupervised use and potential for abuse can lead to significant health risks, emphasizing the need for professional oversight.

Keywords

Acute nephrotoxicity , acute pancreatitis , case reports , drug misuse , hepatotoxicity , orlistat , side effects

References

• Abeer, Q., Abhilasha, J., Ornela, T., Haider, G., Moore, S., & Elona, S. (2025). Exploring Acute Pancreatitis After Orlistat Use: A Case Report. Cureus, 17(3).
• Ahmad, F. A., & Mahmud, S. (2010). Acute pancreatitis following orlistat therapy: report of two cases. JOP. Journal of the Pancreas, 11(1), 61-63.
• Ahmed, N., Nounou, M. I., Abouelfetouh, A., & El-Kamel, A. (2019). Over-the-counter herbal weight loss supplements in Egypt: label claim, microbiological and pharmaceutical quality, and safety assessments. Medical Principles and Practice, 28(2), 167-177.
• Algarni, M., Hadi, M. A., Yahyouche, A., Mahmood, S., & Jalal, Z. (2021). A mixed-methods systematic review of the prevalence, reasons, associated harms and risk-reduction interventions of over-the-counter (OTC) medicines misuse, abuse and dependence in adults. Journal of Pharmaceutical Policy and Practice, 14(1), 76. https://doi.org/10.1186/s40545-021-00350-7
• Bansal, A. B., Patel, P., & Al Khalili, Y. (2024). Orlistat. In StatPearls [Internet]. StatPearls Publishing.
• Buysschaert, B., Aydin, S., Morelle, J., Hermans, M. P., Jadoul, M., & Demoulin, N. (2016). Weight loss at a high cost: Orlistat-induced late-onset severe kidney disease. Diabetes & Metabolism, 42(1), 62-64. https://doi.org/https://doi.org/10.1016/j.diabet.2015.08.006
• Chaudhuri, P. R., Santra, R., Palodhi, S., & Mondal, S. (2013). Orlistat‑induced acute pancreatitis in a type II diabetic and hypothyroid young woman: A case report. International Journal of Health & Allied Sciences, 2(4), 278.
• Daneschvar, H. L., Aronson, M. D., & Smetana, G. W. (2016). FDA-Approved Anti-Obesity Drugs in the United States. The American Journal of Medicine, 129(8), 879.e871-879.e876. https://doi.org/https://doi.org/10.1016/j.amjmed.2016.02.009
• Elsahoryi, N., Al-Sayyed, H., McGrattan, A., Odeh, M., & Hammad, F. (2021). Using of licensed and unlicensed anti-obesity medications among the university students. Nutrition and Food Processing.
• Fernández-Aranda, F., Amor, A., Jiménez-Murcia, S., Giménez-Martínez, L., Turón-Gil, V., & Vallejo-Ruiloba, J. (2001). Bulimia nervosa and misuse of orlistat: Two case reports. International Journal of Eating Disorders, 30(4), 458-461. https://doi.org/https://doi.org/10.1002/eat.1108
• Filippatos, T. D., Derdemezis, C. S., Gazi, I. F., Nakou, E. S., Mikhailidis, D. P., & Elisaf, M. S. (2008). Orlistat-associated adverse effects and drug interactions: a critical review. Drug safety, 31, 53-65.
• Flegal, K. M. (2023). Use and misuse of BMI categories. AMA Journal of Ethics, 25(7), 550-558. Guerciolini, R. (1997). Mode of action of orlistat. Int J Obes Relat Metab Disord, 21 Suppl 3, S12-23.
• Hadváry, P., Lengsfeld, H., & Wolfer, H. (1988). Inhibition of pancreatic lipase in vitro by the covalent inhibitor tetrahydrolipstatin. Biochemical Journal, 256(2), 357-361. https://doi.org/10.1042/bj2560357
• Hall, N. Y., Hetti Pathirannahalage, D. M., Mihalopoulos, C., Austin, S. B., & Le, L. (2024). Global Prevalence of Adolescent Use of Nonprescription Weight-Loss Products: A Systematic Review and Meta-Analysis. JAMA Network Open, 7(1), e2350940-e2350940. https://doi.org/10.1001/jamanetworkopen.2023.50940
• Handing, G., Pathak, U. I., Balasubramanian, A., Liu, A., & Mayer, W. A. (2022). Case - Orlistat-induced calcium oxalate crystalluria. Can Urol Assoc J, 16(10), 371-373. https://doi.org/10.5489/cuaj.7900
• Harp, J. B. (1998). An assessment of the efficacy and safety of orlistat for the long-term management of obesity. The Journal of Nutritional Biochemistry, 9(9), 516-521. https://doi.org/https://doi.org/10.1016/S0955-2863(98)00006-0
• Heck, A. M., Yanovski, J. A., & Calis, K. A. (2000). Orlistat, a New Lipase Inhibitor for the Management of Obesity. Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy, 20(3), 270-279. https://doi.org/https://doi.org/10.1592/phco.20.4.270.34882
• Heymsfield, S. B., Segal, K. R., Hauptman, J., Lucas, C. P., Boldrin, M. N., Rissanen, A., Wilding, J. P. H., & Sjöström, L. (2000). Effects of Weight Loss With Orlistat on Glucose Tolerance and Progression to Type 2 Diabetes in Obese Adults. Archives of Internal Medicine, 160(9), 1321-1326. https://doi.org/10.1001/archinte.160.9.1321
• Humayun, Y., Ball, K. C., Lewin, J. R., Lerant, A. A., & Fülöp, T. (2016). Acute oxalate nephropathy associated with orlistat. J Nephropathol, 5(2), 79-83. https://doi.org/10.15171/jnp.2016.14
• Hvizdos, K. M., & Markham, A. (1999). Orlistat. Drugs, 58(4), 743-760. https://doi.org/10.2165/00003495-199958040-00015
• Kose, M., Emet, S., Akpınar, T. S., Ilhan, M., Gok, A. F. K., Dadashov, M., & Tukek, T. (2015). An Unexpected Result of Obesity Treatment: Orlistat-Related Acute Pancreatitis. Case Reports in Gastroenterology, 9(2), 152-155. https://doi.org/10.1159/000430433
• Lau, G., & Chan, C. L. (2002). Massive Hepatocellular Necrosis: Was it Caused by Orlistat? Medicine, Science and the Law, 42(4), 309-312. https://doi.org/10.1177/002580240204200405
• London, F., Thévenon, A., Levisse, C., Cassim, F., & Tard, C. (2018). Camptocormia and myalgia as the revealing symptoms of a drug-induced myopathy related to chronic orlistat intake: a case report. Acta Neurologica Belgica, 118(1), 115-118.
• Lucas, K. H., & Kaplan-Machlis, B. (2001). Orlistat—a novel weight loss therapy. Annals of Pharmacotherapy, 35(3), 314-328.
• MacWalter, R. S., Fraser, H. W., & Armstrong, K. M. (2003). Orlistat Enhances Warfarin Effect. Annals of Pharmacotherapy, 37(4), 510-512. https://doi.org/10.1345/aph.1C122
• Malhotra, S., & McElroy, S. L. (2002). Orlistat misuse in bulimia nervosa. American Journal of Psychiatry, 159(3), 492-a-493.
• McDuffie, J. R., Calis, K. A., Uwaifo, G. I., Sebring, N. G., Fallon, E. M., Hubbard, V. S., & Yanovski, J. A. (2002). Three‐month tolerability of orlistat in adolescents with obesity‐related comorbid conditions. Obesity Research, 10(7), 642-650.
• Mironica, A., Popescu, C. A., George, D., Tegzeșiu, A. M., & Gherman, C. D. (2024). Social Media Influence on Body Image and Cosmetic Surgery Considerations: A Systematic Review. Cureus, 16(7), e65626. https://doi.org/10.7759/cureus.65626
• Mittendorfer, B., Ostlund Jr, R. E., Patterson, B. W., & Klein, S. (2001). Orlistat Inhibits Dietary Cholesterol Absorption. Obesity Research, 9(10), 599-604. https://doi.org/https://doi.org/10.1038/oby.2001.79 Montero, J. L., Muntané, J., Fraga, E., Delgado, M., Costán, G., Serrano, M., Padillo, J., de la Mata, M., & Miño, G. (2001). Orlistat associated subacute hepatic failure. Journal of hepatology, 34(1), 173.
• Muls, E., Kolanowski, J., Scheen, A., Van Gaal, L., & Group, L. V. G. f. t. O. S. (2001). The effects of orlistat on weight and on serum lipids in obese patients with hypercholesterolemia: a randomized, double-blind, placebo-controlled, multicentre study. International Journal of Obesity, 25(11), 1713-1721. https://doi.org/10.1038/sj.ijo.0801814
• Napier, S., & Thomas, M. (2006). 36 year old man presenting with pancreatitis and a history of recent commencement of orlistat case report. Nutrition journal, 5(1), 19. https://doi.org/10.1186/1475-2891-5-19
• Phan, D. T. A., Kongkaew, C., Heinrich, M., Dao, T. C. M., & Vo, T. H. (2025). From ‘traditional’remedies to ‘modern’supplements: a systematic review and meta-analysis of pharmaceutical adulteration in weight-loss natural products. Frontiers in Pharmacology, 16, 1594975.
• Ringman, J. M., & Mozaffar, T. (2008). Myopathy associated with chronic orlistat consumption: A case report. Neuromuscular Disorders, 18(5), 410-412. https://doi.org/https://doi.org/10.1016/j.nmd.2008.03.005
• Sall, D., Wang, J., Rashkin, M., Welch, M., Droege, C., & Schauer, D. (2014). Orlistat-induced fulminant hepatic failure. Clinical Obesity, 4(6), 342-347. https://doi.org/https://doi.org/10.1111/cob.12075
• SAYGILI, U. E. S., & ERDAL, M. (2001). Yeni Teknolojilerin Sağlik Sektöründeki Etkileri Ve Internet Kullanimi.
• Schwartz, S. M., Bansal, V. P., Hale, C., Rossi, M., & Engle, J. P. (2008). Compliance, Behavior Change, and Weight Loss With Orlistat in an Over-the-Counter Setting. Obesity, 16(3), 623-629. https://doi.org/https://doi.org/10.1038/oby.2007.96
• Singh, A. (2007). Acute oxalate nephropathy (first report) in a patient with chronic kidney disease: case report. Reactions, 1135, 20.
• Stalder, H., Oesterhelt, G., & Borgström, B. (1992). Tetrahydrolipstatin: Degradation products produced by human carboxyl-ester lipase. Helvetica Chimica Acta, 75(5), 1593-1603. https://doi.org/https://doi.org/10.1002/hlca.19920750513
• Steffen, K. J., Mitchell, J. E., le Grange, D., Crow, S. J., Attia, E., Bulik, C. M., Dellava, J. E., Bermudez, O., Erickson, A. L., Crosby, R. D., & Bansal-Dev, V. P. (2010). A prevalence study and Description of alli® use by patients with eating disorders. International Journal of Eating Disorders, 43(5), 472-479. https://doi.org/https://doi.org/10.1002/eat.20829
• Tushar, M. I., & Kersbergen, I. (2024). Factors associated with over-the-counter drug misuse among young people: a narrative review. European Journal of Public Health, 34(Supplement_3). https://doi.org/10.1093/eurpub/ckae144.1671
• Veeramachaneni, G. K., Raj, K. K., Chalasani, L. M., Annamraju, S. K., Js, B., & Talluri, V. R. (2015). Shape based virtual screening and molecular docking towards designing novel pancreatic lipase inhibitors. Bioinformation, 11(12), 535.
• Weir, M. A., Beyea, M. M., Gomes, T., Juurlink, D. N., Mamdani, M., Blake, P. G., Wald, R., & Garg, A. X. (2011). Orlistat and Acute Kidney Injury: An Analysis of 953 Patients. Archives of Internal Medicine, 171(7), 702-710. https://doi.org/10.1001/archinternmed.2011.103
• Wilson, N. S., Shah, N., Manitpisitkul, W., Twadell, W. S., Barth, R. N., Philosophe, B., & Fayek, S. A. (2011). Liver Failure Requiring Transplantation After Orlistat Use. Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy, 31(11), 1145-1145. https://doi.org/https://doi.org/10.1592/phco.31.11.1145
• Zhang, X., Liu, J., Ni, Y., Yi, C., Fang, Y., Ning, Q., Shen, B., Zhang, K., Liu, Y., Yang, L., Li, K., Liu, Y., Huang, R., & Li, Z. (2024). Global Prevalence of Overweight and Obesity in Children and Adolescents: A Systematic Review and Meta-Analysis. JAMA Pediatr, 178(8), 800-813. https://doi.org/10.1001/jamapediatrics.2024.1576
• Zhu, J., Hu, M., Liang, Y., Zhong, M., Chen, Z., Wang, Z., Yang, Y., Luo, Z., Zeng, W., Li, J., Du, Y., Liu, Y., & Yang, C. (2024). Pharmacovigilance analysis of orlistat adverse events based on the FDA adverse event reporting system (FAERS) database. Heliyon, 10(14). https://doi.org/10.1016/j.heliyon.2024.e34837