If you have high blood pressure, the last thing you’d want to hear is that the meds you’re taking could be making things worse. L-type calcium channel blockers (LCCBs) — the most widely used drugs for treating hypertension — may harm the heart as much as help it, according to a new study.

The researchers from Penn State found that in rats and human cells in vitro, LCCBs cause changes in blood vessels, which reduce blood flow and increase pressure. The team also found that LCCBs are associated with a greater risk for heart failure.
“In the United States, nearly half of all adults — or just over a hundred million — have hypertension, and its prevalence is increasing; worldwide, the condition is expected to affect 1.56 billion people by 2025,” said Mohamed Trebak, professor of cellular and molecular physiology, Penn State. “L-type calcium channel blockers are one of the most widely prescribed drugs to treat hypertension, yet we have found that these drugs may cause the same type of damage they are intended to prevent.”
Too much calcium in the wrong place…
Trebak explained that vascular smooth muscle cells (VSMCs) make up the walls of blood vessels. These VSMCs help control blood flow by contracting and relaxing. This activity is regulated by the concentration of calcium within the cells.
In individuals suffering from hypertension, there is too much calcium present in VSMCs, which trigger the cells to divide and multiply. This physiological “remodeling,” causes blood vessel walls to thicken and stiffen. Over time, blood pressure steadily rises.
“L-type calcium channel blockers were created to prevent this from happening,” said Trebak. “Yet, we found that these drugs also simultaneously cause remodeling and proliferation of VSMCs through another mechanism.”
Higher Incidences of Heart Failure
Epidemiological data from the Penn State clinical database found that incidences of heart failure were significantly higher in hypertensive patients treated with LCCBs than in hypertensive patients treated with other types of hypertension medications.
“Treatment with LCCBs is clinically associated with elevated incidence of heart failure, which prompts a careful examination of the use of LCCBs during chronic hypertension where vascular remodeling is evident,” said Trebak.
These findings suggest that extra care should be taken when prescribing to hypertensive patients infected with COVID-19 or older adults with advanced hypertension, as LCCBs may exacerbate their vascular damage.