The most serious side effects of Levaquin include heart failure, heart attacks, aortic aneurysms, nerve damage, and tendon ruptures.
Levaquin and Heart Failure
Levaquin damages collagen and connective tissue throughout the body, including the heart. In a recent study of 9 million people in the U.S., researchers found that Levaquin increases the risk of heart valve damage by destroying collagen in the tiny flaps that open and close in the heart valves. When the heart valves do not work properly, blood can leak backward when the heart pumps. Over time, this forces the heart to work harder and increases the risk of heart failure.
Levaquin and Aortic Aneurysms
In December 2018, the FDA ordered drug-makers to update the label on Levaquin to warn about aortic aneurysms. This side effect occurs when Levaquin damages collagen and other delicate connective tissues in the aorta, which is the largest blood vessel in the body. Patients with high blood pressure have a higher risk of this severe side effect, according to the FDA. In severe cases, the aorta bursts open and causes massive internal bleeding and death. Patients can rapidly go into shock, a life-threatening emergency in which blood pressure plummets and vital organs shut down.
Levaquin and Nerve Damage
Experts have known that Levaquin and other antibiotics in the fluoroquinolone class can increase the risk of nerve damage since 2004. The disease, known as peripheral neuropathy, can occur rapidly and cause permanent pain and other complications. The FDA strengthened warnings about this risk in August 2013.
Levaquin and Tendon Ruptures
Levaquin is associated with an increased risk of tendon damage, including tendinitis and tendon ruptures. These side effects can be very painful and limit mobility. In 2008, the FDA added a Boxed Warning to emphasize this risk for patients over 60 years old, patients on corticosteroids, and recipients of heart, lung, or kidney transplants.