Every two months, scientists discover novel applications for GLP-1 agonist medications, such as Mounjaro and Ozempic — now including their use as a therapy for substance abuse. This represents a classic example of drug repurposing, a strategy that proved life-saving during the COVID-19 pandemic.
The range of uses for GLP-1 agonist drugs continues to expand: Initially developed for type 2 diabetes management, they later gained popularity as weight-loss injections.
Evidence also indicates that GLP-1 agonists, including semaglutide and tirzepatide — marketed as Mounjaro, Ozempic, Wegovy, and Zepbound —
decrease the likelihood of cardiovascular conditions,
safeguard kidney and liver function,
lessen inflammation and pain,
curb addiction and substance misuse,
assist individuals with arthritis,
and aid those suffering from sleep apnea.
View the situation from a high-level perspective, and you will recognize a textbook instance of what industry professionals call drug repurposing: a single medication serving multiple purposes.
**Repurposing medications during a health emergency**
What some may perceive as a clever strategy to profit from an already popular drug is, for others, a cost-effective and time-saving method to preserve lives.
The COVID-19 pandemic serves as a prime example: consider the drugs dexamethasone and baricitinib.
When COVID emerged, dexamethasone and baricitinib were already available. They are prescribed to treat inflammation or swelling.
Dexamethasone has a wide range of applications — it can address arthritis, asthma, blood or bone marrow disorders, kidney issues, skin conditions, and severe cases of multiple sclerosis.
Baricitinib is employed for moderate to severe rheumatoid arthritis, moderate to severe atopic dermatitis, and severe alopecia areata, an autoimmune condition that attacks hair follicles, leading to hair loss.
Subsequently, physicians experimented with these drugs to combat inflammation in COVID patients — this occurred before and during the early phases of COVID vaccine development.
In 2021, the UK's National Health Service reported that dexamethasone saved 22,000 lives in the UK and approximately one million globally.
Meanwhile, baricitinib helps regulate elevated cytokine levels and inflammation. During COVID, doctors and researchers observed "cytokine storms" in patients — a condition where the immune system becomes hyperactive, resulting in severe inflammation.
Based on these experiences during the pandemic, the European Commission planned to enhance support for drug repurposing to explore treatments for cancer.
**A health caution regarding repurposed drugs**
None of the above should be interpreted as suggesting — nor is it DW's recommendation — that anyone use GLP-1 agonists, or any other medication, for "off-label" or unapproved conditions without personalized, professional medical advice. The use of any drug carries risks, and as the applications of GLP-1s have expanded, for example, so too have lesser-known dangers come to light.
It should also come as no surprise that GLP-1 agonists offer such widespread health advantages.
If these drugs facilitate weight loss, prevent weight gain, or reduce addictive behaviors, they will consequently lower the risk of type 2 diabetes — which is largely driven by "lifestyle choices" such as overeating — and that, in turn, will ease the burden on every organ in the body.
It almost seems as if the original creators of the first GLP-1 agonist had mapped out a series of follow-ups — but they did not invent drug repurposing.
However, as we've highlighted above, drug repurposing typically occurs by accident or during moments of extreme urgency, such as the COVID-19 pandemic.
**A brief history of drug repurposing**
The following list is by no means comprehensive. It might best be viewed as an illustration of the human body's interconnectedness — that we function as a single system, and thus it stands to reason that one drug can serve multiple purposes.
In cancer treatment, there are two notable examples — the first being the drug raloxifene. Raloxifene was initially developed to treat osteoporosis.
Later, a large-scale study across 25 countries demonstrated its potential for repurposing in individuals at high risk of breast cancer. In that study, the risk of invasive breast cancer dropped by 76% over three years of treatment in postmenopausal women with osteoporosis. The US Food and Drug Administration (FDA) — regarded as the global benchmark for drug and vaccine approval — authorized raloxifene for the prevention of invasive breast cancer.
Thalidomide — a drug perhaps best known for its controversial history in the 1950s as a sedative for pregnant women with morning sickness, which was withdrawn after being linked to severe skeletal birth defects — was repurposed and approved by the FDA about 60 years later for use in combination with dexamethasone in patients newly diagnosed with multiple myeloma. Multiple myeloma is an incurable but manageable blood cancer.
More recently, studies have explored repurposing drugs for Alzheimer's Disease, a form of neurodegeneration or dementia. The prevalence of dementia is rising rapidly.
A 100-year-old vaccine against tuberculosis, known as Bacillus Calmette-Guerin, has been found to regulate blood sugar levels — and, consequently, the need for insulin — in individuals with type 1 diabetes.
But perhaps the most famous — or infamous — case of drug repurposing is that of Viagra, or sildenafil.
The drug was originally developed to treat cardiovascular conditions, such as chest pain or angina. It was then discovered — to make a long story short — to assist men with erectile dysfunction. It subsequently became known as the "little blue pill."
**Another caution — this time from history**
Writing in the British Medical Journal in 1998, Abi Berger, a general practitioner, observed: "It must surely be every drug company's dream: to have a product so sexy that the need for marketing and public relations has been obviated by a tidal wave of media hype."
It seems the excitement surrounding GLP-1 agonists is a case of "history repeating itself."
So, let's conclude with a historical warning: Not only did the hype strain the production of sildenafil back in the day, but more recent studies have also linked it to abnormal heart rhythms.
And the same may hold true for GLP-1 agonists: the evidence for their repurposed uses — their true benefits and drawbacks — may only become apparent many years from now.
Edited by: Jakov Leon