Epilepsy commonly begins in childhood, but it can start at any age. Older adults may not come to mind as being at risk of developing the condition, but there’s strong evidence that people aged around 60 have an increased risk of both epilepsy and acute seizures. The risk rises sharply for over-60s living in wealthier countries.
For this older population, the leading cause of seizures and epilepsy is stroke. Chronic high blood pressure, even in the absence of stroke, also increases epilepsy risk. While medications can be given to control seizures, there’s no approved drug that prevents epilepsy in these at-risk people.
A new study led by the Stanford University School of Medicine (Stanford Medicine) has found that an existing class of drugs given to lower high blood pressure reduces the risk of epilepsy developing in older adults.
“This is incredibly exciting because we don’t currently have any medications that prevent epilepsy,” said Kimford Meador, a professor of neurology and neurological sciences at Stanford and the study’s corresponding author. “I hope these initial findings lead to randomized clinical trials.”
A 2022 study of more than 160,000 Germans found that those taking angiotensin receptor blockers (ARBs), one of the classes of drugs used to treat high blood pressure, had a reduced risk of developing epilepsy. Angiotensin is a hormone the body produces that constricts the blood vessels, driving up blood pressure. ARBs stop angiotensin from acting, reducing blood pressure and decreasing inflammation in blood vessels and other organs, including the brain. The generic names of ARBs always end in ‘sartan’ – for example, candesartan (Atacand), eprosartan (Teveten), irbesartan (Avapro), losartan (Cozaar), Olmesartan (Benicar), telmisartan (Micardis), and valsartan (Diovan).
For the current study, the researchers went bigger. Consulting a national database that included information on health care claims from Americans enrolled in either commercial health insurance plans or Medicare, they focused on 2.2 million individuals who’d been diagnosed with high blood pressure, were prescribed at least one medication for it, and did not already have epilepsy or heart disease. Study participants – with a mean age of 61, 49.5% of whom were female – were more racially diverse than those in the German study.
Of the study participants, around 14% were taking ARBs, while most took other classes of medications for high blood pressure, including beta-blockers, calcium channel blockers, and angiotensin-converting enzyme inhibitors (ACEIs). While all of the classes lower blood pressure, each has a different mechanism of action.
Overall, the researchers found that between 2010 and 2017, people taking ARBs had a 20% to 30% lower risk of developing epilepsy than those taking other blood pressure-lowering medications. The difference remained when they removed people with strokes from their analysis, suggesting that the lower epilepsy risk was not a result of a decreased risk of stroke.
“What we’ve done is replicate what was found in Germany but in a larger and completely different population,” Meador said. “That really increases the strength of the signal and tells us that there’s something real going on here.”
One ARB, losartan, significantly lowered epilepsy risk, but the researchers say that more research is needed to confirm this. While the researchers couldn’t explain why ARBs caused this reduced risk, their findings fit with previous research suggesting that ARBs’ anti-inflammatory effects might be a contributing factor. Brain inflammation following a stroke or traumatic brain injury is a risk factor for the development of epilepsy.
Randomized clinical trials are needed to prove the association between ARBs and reduced epilepsy risk. However, the researchers say that all blood pressure medications will likely influence that risk. By controlling high blood pressure through medication and/or lifestyle changes, people are reducing the potential impact of that particular risk factor.
Researchers from the University of Rhode Island and Brown University were also involved in the study, which was published in the journal JAMA Neurology.
Source: Stanford Medicine