People with high blood pressure who regularly take common painkillers known as non-steroidal anti-inflammatory drugs (NSAIDs) may increase their risk of developing chronic kidney disease, a study from Taiwan suggests.

While some previous research has linked NSAIDs to impaired kidney function, the results have been mixed and often overlooked the effects on people with high blood pressure, or hypertension, which itself carries an elevated risk for kidney damage.

For the current study, researchers examined data on more than 30,000 people with hypertension and found that those who'd been taking NSAIDs for at least three months were 32 percent more likely to have chronic kidney disease than participants who didn’t use the pills.

In addition, participants who typically took NSAIDs more than once a day had a 23 percent greater risk of developing chronic kidney disease than people who didn’t use the pills.

Even if patients used NSAIDs for less than three months, they still had an 18 percent higher risk of developing chronic kidney disease, the study found.

“Our results suggest that NSAID duration plays a role in chronic kidney disease among subjects with hypertension,” said senior study author Hui-Ju Tsai, a scientist at the Institute of Population Health Sciences, National Health Research Institutes in Zhunan.

“Physicians should exercise caution when administering NSAIDs to people with hypertension and closely monitor renal function,” Tsai said by email.

NSAIDs are among the most commonly used pills in the world for ailments ranging from headaches to fever, arthritis and menstrual cramps. This family of medicines includes over-the-counter drugs such as aspirin, which can also help prevent strokes and heart attacks, as well as ibuprofen (Motrin, Advil) and naproxen (Aleve). Prescription NSAIDs include naproxen (Naprosyn) and celecoxib (Celebrex).

About one in three adults have high blood pressure, an often silent condition that can damage the heart and blood vessels and lead to stroke, kidney failure and other problems, according to the U.S. National Institutes of Health.

Renal damage can develop in people with hypertension because the kidneys are laced with dense blood vessels transporting high volumes of blood. Uncontrolled hypertension can make arteries around the kidneys harden, weaken or narrow, damaging the organs by restricting blood flow.

One shortcoming of the study is a lack of blood test data to confirm the severity of kidney disease, the authors note in the journal Hypertension. It’s also possible that some patients with kidney disease weren’t identified due to a lack of clinical or laboratory data.

In addition, the study only tracked prescription NSAID use. In Taiwan, the vast majority of people taking these drugs get prescriptions because the cost is much lower than it would be for over-the-counter versions of the drugs, the authors point out.

While past research has suggested that kidney damage linked to NSAIDs might be reversed once the pills are stopped, the current study points to the possibility that long-term use of these painkillers might lead to permanently impaired renal function, said Dr. Liffert Vogt, a nephrologist at Academic Medical Center at the University of Amsterdam in The Netherlands.

NSAIDs can cause the kidney to retain salts and water, prompting a rise in blood pressure and potentially making medications to lower hypertension ineffective, Vogt, who wasn’t involved in the study, said by email.

“When a patient is already treated with a blood pressure lowering drug, NSAIDs should be avoided,” Vogt said. “The negative effects of NSAIDs on the kidneys can be explained by their effects on blood pressure control.”