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With the emergence of newer and more effective weight management medications, coupled with social and lay media spreading the word at a furious pace, use of these treatments has reached a previously unsurpassed level.  How long do people stick with weight management medication, and why does it matter?

A recent retrospective cohort study gives us updated data on this topic from 2015-2022, evaluating electronic health records from a US database.  The purpose of the study was to determine how many patients stuck with their initial weight management medication prescription at 3, 6, and 12 months.   The medications evaluated were naltrexone-bupropion (Contrave), semaglutide 2.4mg (Wegovy; they also evaluated ‘off label’ use of semaglutide as Ozempic, which is approved for use in type 2 diabetes), liraglutide 3mg (Saxenda; they also evaluated ‘off label’ use of liraglutide as Victoza, which is approved for use in type 2 diabetes), orlistat (Xenical), and phentermine-topiramate (Qsymia – not available in Canada).   Tirzepatide (Mounjaro, approved for type 2 diabetes) was not included in the analysis as it was first approved in USA in 2022 (it was subsequently also approved for obesity as Zepbound in November 2023).

The study identified 1,911 people who filled a prescription for weight management medication.  The average age of these people was 44, median baseline BMI was 38, 75% were female, 76% where white, and 84% had private health insurance.  A quarter of patients were prescribed semaglutide, 34% naltrexone-bupropion, 26% phentermine-topiramate, 14% liraglutide, and 1% orlistat.

They found that 44% were persistent with their obesity medication at 3 months, 33% at 6 months, and only 19% at the one-year mark.  The lowest persistence at 1 year was with naltrexone-bupropion (10%), and the highest with semaglutide (40%).   Persistence at 1 year was markedly better for those prescribed weight management medication later during the study time frame (eg 2022) than earlier (eg 2015).  Persistence at 1 year also varied by insurance carrier (for those who were privately insured) but was not associated with age, ethnicity, gender, neighborhood socioeconomics, or comorbidity index (index of other health conditions).  For those who were persistent with treatment at 6 months, each 1% increase in weight loss at 6 months was associated with a 6% greater likelihood of persistence with treatment at 1 year.   People who were persistent with their obesity medication at 1 year experienced a mean 10% weight loss, while those who stopped treatment experienced only a 2% weight reduction.

Why do people stop their weight management medication?  While these data give some hints as to why, here is my expanded list of reasons:

  1. Lower efficacy of older treatments. While we were excited to see an average weight loss of 5% with older treatments, newer treatment options are getting well into double digit weight loss for many people. This may partially explain why persistence with semaglutide was higher in this study. We know from the ACTION studies [conducted in Canada (disclosure, I am a coauthor), USA, and globally] that people with obesity wish to lose an average of about 19% weight, so newer treatments are coming closer to these goals.
  2. Patients may not be advised what results to expect from weight management medication.   Sometimes people who have started treatment haven’t been advised how much weight loss is typically seen with a particular medication, nor how long it takes to get there.  It’s also important that people understand that weight loss varies greatly from one person to the next.
  3. Cost, access, and insurance (or lack therof).  While the cost of medication varies greatly by country (with USA topping the list), these treatments are expensive everywhere. Some people who are having success with treatment just can’t afford to take it long term.  Many insurance companies are making it harder to get weight management medication paid for.  The global shortages of these medications is forcing discontinuation in many cases.
  4. Side effects.  Obesity medications have potential side effects (read about these in our Canadian 2022 Obesity Guidelines Pharmacotherapy chapter – disclosure, I am the lead author.  Read more on updates since 2022 by searching each medication in the search box at the top right of this blog.)  While some people simply do not tolerate particular medications, side effects can often be navigated with good support in titrating medication and finding strategies to manage mild side effects, which tend to be more common earlier in treatment with semaglutide, liraglutide, and naltrexone-bupropion.
  5. People may not be advised that weight management medication is intended to be long term, just as for any chronic medical condition.  When weight loss medication is stopped, weight almost always goes back up.  I think the improvement in persistence in later years of this study may in part reflect a better understanding of the need to treat long term.
  6. People may not be informed of the health benefits beyond weight loss.  We are learning so much about the benefits of weight loss medication to improve other health issues like blood sugar control, diabetes prevention, fatty liver disease, heart failure, sleep apnea, and cardiovascular risk, with some of these benefits being independent of the amount of weight lost.  So, even if the numbers on the scale are not meeting the person’s individual goals, with education on health benefits and a reframe of goals to encompass these health benefits, I would expect to see better persistence with treatment.

BOTTOM LINE:   Persistence with weight management medication remains poor, though is improving in more recent years.   Supporting people on these treatments to frame expectations, understand health benefits and need for long term treatment, navigate side effects, and advocate for long term access can pave the way for better persistence in the long run.

Disclaimer:  I receive honoraria as a continuing medical education speaker and consultant from the maker of semaglutide and liraglutide (Novo Nordisk), naltrexone/bupropion (Bausch), and tirzepatide (Eli Lilly).  I am/have been an investigator in clinical trials of semaglutide, liraglutide, and tirzepatide.

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