Developing new drugs is a slow and expensive process. From start to finish, clinical trials can take years or even a decade, and cost hundreds of millions of dollars. Some researchers looking for new Alzheimer’s drugs are taking another approach that avoids these problems: repurposing drugs that are already out there. 

Studies following people taking various drugs over decades have provided clues that drugs intended to treat high blood pressure, diabetes, or epilepsy might also protect the brain. Since these drugs are already proven safe, scientists can skip the earliest stages of clinical trials, speeding up the discovery of a potential new treatment for the disease.

These repurposed drugs are currently being tested in Phase 2 and Phase 3 trials, and we may know in the coming years whether they might treat or slow cognitive decline. 

A blood pressure drug for Alzheimer’s?

Bumetanide is a drug that helps the body get rid of excess fluids to treat high blood pressure. Recent studies have found that people with high blood pressure taking this drug were less likely to develop Alzheimer’s disease.

Based on this observation, researchers have designed a Phase 2 clinical trial, currently recruiting 40 older adults in the earliest stages of Alzheimer’s. This trial will test whether the drug is safe and the side effects aren’t severe. The trial is expected to finish in 2025, and if the drug shows promise, researchers will conduct a definitive Phase 3 trial to see whether it’s effective.

Can drugs like Wegovy and Ozempic protect the brain?

A class of diabetes drugs called GLP-1 agonists like Wegovy and Ozempic, also approved for treating obesity, can reduce the risk of heart attacks and stroke. A few studies also suggest these drugs could protect against Parkinson’s, Alzheimer’s, and other forms of dementia.

Drugmaker Novo Nordisk is currently putting these drugs to the test with two Phase 3 trials of the GLP-1 drug semaglutide, sold as Wegovy and Ozempic. The trials follow 1,840 participants over more than three years to see if the drug is effective in the early stages of Alzheimer’s disease. Results from these trials are expected by the end of 2025. 

An epilepsy treatment could help restore memory

Levetiracetam is a drug approved for treating epilepsy. Scientists discovered that the drug might have an unexpected benefit: preventing memory loss. 

The drug is being tested in a Phase 2 trial to see if it could treat memory issues in people with Alzheimer’s. Participants are also currently taking drugs (like Razadyne, Aricept, or Exelon) to treat other Alzheimer’s symptoms. The trial is set to finish at the end of the year.

Researchers have also developed a long-lasting version of levetiracetam, called ABG101, to see if it could ease symptoms in people with mild cognitive impairment caused by Alzheimer’s disease. However, its Phase 3 trial failed to show any benefits. 

An inexpensive diabetes pill might treat Alzheimer’s

Metformin is a medication commonly prescribed for treating Type 2 diabetes. It lowers blood glucose and helps restore the body’s sensitivity to insulin, which helps regulate sugar metabolism. 

Studies that followed people taking metformin checked whether they were protected against Alzheimer’s, but the results were mixed. Scientists are currently running a clinical trial of 600 older adults at risk of diabetes to test whether the drug could protect their brains against cognitive decline and dementia. The study is set to finish in 2026.

Taking a closer look at drugs that treat other diseases could help scientists find new treatments faster. Scientists testing these drugs can skip the earliest stages of clinical trials since they’re already approved and would be cheaper for patients than brand new drugs.