Drug combination linked to kidney failure

Blood pressure medication raises risks when used with common painkillers, Montreal study finds

A new study showing a triple combination of blood pressure drugs and common painkillers can increase the risk of serious kidney problems means doctors will have to be extra vigilant when prescribing this particular concoction of drugs.

A team of researchers from the Jewish General Hospital and McGill University found a triple therapy combination of a diuretic with a second antihypertensive drug plus a painkiller was associated with a 30 per cent higher risk of kidney fail- ure — and the risk was 80 per cent higher during the first 30 days of treatment.

Samy Suissa, an epidemiologist at the Jewish, led the study and said what was particularly worrisome about the finding is that high blood pressure is common and it is also quite common that someone be prescribed more than one antihypertensive drug to combat it.

“Many people will take two drugs simultaneously and then have arthritis, or some other kind of pain, that requires non-steroidal anti-inflammatory drugs (NSAIDs),” Suissa said. “Now we realize this is a triple threat and physicians will have to be vigilant about following this up because some people, especially elderly people, require this combination of drugs.”

He said one surprise was that people taking only one blood pressure drug and a painkiller didn’t seem to be at increased risk for kidney failure.

But it’s also a little premature to celebrate. The study was published in the medical journal bmj.com with an accompanying editorial from the London School of Hygiene and Tropical Medicine, which warned “the jury is still out on whether double drug combinations are indeed safe.”

And it further predicted the study “probably underestimates the true burden of drug-associated acute kidney injury.”

The research team used the largest database of primary care records in the world to identify almost 500,000 people who received blood pressure drugs in the U.K. between 1997 and 2008.

The drugs included angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARB) and diuretics, along with NSAIDs, which do not include Tylenol but could include Advil, Aleve and Aspirin.

However, Suissa said the kidney problem wasn’t the result of just taking painkillers with the other drugs on one occasion, but over 30 days.

And he found it surprising that 11 per cent of the group were using all three drugs, a fairly high proportion, although he noted there were many elderly people.

Patients were tracked for six years, during which time 2,215 were found to have acute kidney injury that prompted admission to hospital or dialysis.

The study concluded vigilance was required, especially in the early part of treatment, “and a more appropriate choice among the available anti-inflammatory or analgesic drugs could therefore be applied in clinical practice.”

While kidney failure was still a rare event, Suissa said, it requires a lot of attention if it occurs.

“We certainly wouldn’t want to cause anything that wouldn’t happen otherwise,” he said.

“If our kidneys are fine, there’s no reason to hurt them.”