The agency strengthened kidney warnings for canagliflozin, the active ingredient in Invokana and Invokamet, and dapagliflozin, the active ingredient in Farxiga and Xigduo XR.
From March 2013 (when Invokana was approved) to October 2015, the FDA received 101 confirmed cases of kidney damage.
These medications control diabetes by forcing the kidneys to remove more sugar from the body in urine. Patients can urinate so much they become dehydrated, which makes it hard for the kidneys to do their job. In severe cases, the kidneys suddenly stop working.
Patients should seek medical attention immediately if they experience symptoms of kidney damage, such as decreased urination and swelling in the legs or feet. These are signs that the kidneys are not working, causing dangerous levels of toxins to build up in the body.
According to the FDA, risk-factors for kidney damage include:
- Decreased blood volume
- Chronic kidney insufficiency
- Congestive heart failure
The risk also increases for patients on other medications, including diuretics, blood pressure medications known as angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and non-steroidal anti-inflammatory drugs (NSAIDs).
The problem is that a large percentage of people with diabetes take these other medications. Diuretics are often prescribed in combination with ACE inhibitors or ARBs to control blood pressure. NSAIDs include common painkillers like ibuprofen and naproxen.
Diuretics reduce the amount of water in the body, which also decreases blood-volume and the amount of blood that passes through the kidneys. The kidneys can compensate by tightening blood vessels, but ACE inhibitors and ARBs interfere with this safety mechanism.