First Detailed Data Show Risk of Using Aliskiren With ACE Inhibitors or ARBs TORONTO -- January 12, 2012 -- Researchers at have published the first detailed figures showing the risk of using aliskiren (Rasilez) in combination with certain other blood pressure-lowering medications. Findings were fast-tracked into publication this week in the British Medical Journal. It provided the first specific data of the risks of taking the drug combinations The pharmaceutical company Novartis terminated a large, international clinical trial of the drug last month after finding an increased incidence of non-fatal stroke, renal complications, hyperkalemia, and low blood pressure after 18 to 24 months. As a result, Health Canada said on December 22, 2011 that it would review the safety of aliskiren. Even before Novartis halted its clinical trial, Ziv Harel, MD, St. Michael’s Hospital, Toronto, Ontario, and colleagues were examining the interaction between aliskiren and angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blocker (ARB) drugs. After reviewing 10 large randomised clinical trials on the combination of these drugs, they found that patients taking aliskiren as well as an ACE inhibitor or ARB, had about a 50% greater risk of developing hyperkalemia than those taking only an ACE inhibitor or ARB. In addition, patients taking a combination of aliskiren plus an ACE inhibitor or ARB had a 70% greater risk of developing hyperkalemia than those taking aliskiren alone. Previous research in 2008 found an increased risk of hyperkalemia and acute kidney failure in people taking a combination of ACE inhibitors and ARBs. So when aliskiren entered the market, clinicians were keen to replace one of those drugs in the combination. Dr. Harel was surprised to find no increased risk of kidney failure in patients taking aliskiren and an ACE inhibitor or ARB over those taking just 1 of the drugs. He said that might be because the short-term clinical trials they reviewed used a conservative definition of kidney failure or the patients were being monitored so closely that any sign of kidney damage would have been detected and treated quickly. Dr. Harel said he believes that clinicians should offer alternatives to prescribing combinations of medications with a strong potential for life-threatening adverse events. SOURCE: St. Michael’s Hospital