Medtronic warned doctors and patients that two insulin pumps the company sold as waterproof can develop stress cracks over time and take in water.
The company said Medtronic MiniMed Paradigm 511 and Paradigm 512 insulin pumps should not be worn while swimming or participating in other water activities, and recommended that patients disconnect the pumps when showering.
No health problems were reported because of the malfunction, but Medtronic said more pumps were being returned this summer because of water exposure as people began swimming more. The company would not say how many were returned, but said the number was small.
Medtronic voluntarily notified the Food and Drug Administration of the problem and sent out letters this week to physicians and patients.
The devices allow users to control insulin levels with a battery-operated pump contained in a plastic case about the size of a beeper connected to the body by a thin plastic tube inserted just under the skin.
If the pump turns off due to water damage, its screen will go blank and its buttons won’t work. If that happens, patients should check their blood sugar levels and treat any high blood glucose with an insulin injection, the company said.
The company will replace water-damaged pumps, McLaughlin said.