Diabetes Drug Byetta Linked to Kidney Problems
The FDA has received 78 reports of kidney problems related to Byetta, a drug by Amylin Pharmaceuticals and Eli-Lilly prescribed to treat type 2 diabetes. With the new findings, the drug’s label will be updated to warn doctors and patients about this possible side effect.
Byetta (exenatide) was approved in 2005. It's known as an incretin mimetic, which copies the action of incretin GLP-1, a hormone that is released in response to eating food which causes insulin to be secreted from the pancreas to lower blood glucose. The drug is injected twice a day, similar to insulin.
The drug recently was approved as a stand-alone treatment for controlling blood sugar, whereas previously it was prescribed for patients also on other diabetic therapies.
The reports of kidney failure were filed between April 2005 and October 2008. Sixty-two of the cases were for acute renal failure and 16 were cases of renal insufficiency. Most of the problems occurred in patients with pre-existing kidney disease or one or more risk factors for developing kidney problems. 91% of the patients were hospitalized, 18 required dialysis, 2 had kidney transplants, and 4 died. 80% stopped taking Byetta, and half of those patients had improvements to kidney function after discontinuing the drug.
Between 2005 and 2008, approximately 7 million prescriptions were written for Byetta. The FDA said, “Therefore, the 78 reported cases of altered renal funcion represent a small percentage of the total number of patients who have used the drug.”
Some of the side effects of Byetta can contribute to kidney problems. For example, diarrhea, nausea and vomiting can lead to dehydration. Patients are encouraged to ask their physicians about their kidney function before taking Byetta and to monitor for signs and symptoms while taking the drug. Symptoms of kidney disease include changes in urine color, swelling in the feet and legs, fatigue, nausea or vomiting, and dull ache in the mid to lower back. If left untreated, kidney damage can worsen and lead to kidney failure.
Kidney malfunction may also occur as a consequence of diabetes itself, other chronic conditions, such as pancreatitis and hypertension. Concomitant use of certain medications (nonsteroidal anti-inflammatory drugs, diuretics, and antihypertensives) can also lead to kidney problems. Discontinuation of Byetta should only be considered if kidney dysfunction cannot be explained by these or other causes.
The FDA is advising physicians to avoid prescribing Byetta for patients with severe renal impairment, identified as creatinine clearance less than 30 mL per minute, or end-stage renal disease. It also recommends using caution when initiating or increasing doses from 5 micrograms to 10 micrograms in patients with moderate renal impairment. Physicians should monitor patients for the development of kidney dysfunction while on Byetta.
In 2007, Byetta was linked to a higher risk of acute pancreatitis, a potentially life-threatening inflammation of the pancreas. In October 2007 and August 2008, the FDA issued safety alerts about the reports that included cases of hemorrhagic pancreatitis and nectrotizing pancreatitis, which can be fatal. The symptoms of pancreatitis include nausea, vomiting, severe abdominal pain, a rise or fall in blood pressure, and increase heart or respiratory rates.
Adverse events for any medication should be reported to the FDA’s MedWatch Safety Information and Adverse Event Reporting Program.
Denise Reynolds RD LDN