What is antibiotic lock therapy?

Antibiotic lock therapy (ALT) is a way to clear bacteria from inside a long-term catheter that's in a blood vessel. A catheter is a thin flexible tube. It carries fluids, medicine, or nutrients into the blood.

In ALT, strong antibiotics are placed in the catheter for long enough to kill the bacteria.

ALT can help you keep your catheter if you have a blood infection. Long-term catheters help you get nutrition and medicines, such as chemotherapy. But using them increases the risk of infections in the blood. That can be serious. If there is a blood infection, the catheter may be taken out.

But in some cases, your doctor may try to treat the infection in the blood and kill the bacteria in the catheter while leaving the catheter in place. Trying this depends on how bad the blood infection is and what kind of bacteria are involved.

The first step in ALT is removing the fluid from the catheter. A strong dose of an antibiotic is placed in the catheter. The dose is just enough to fill the catheter without getting the medicine into your body. The antibiotic is left there for up to 12 hours or more.

During that time, the catheter will not be used for nutrition or medicine. It may be marked "Do not use." When treatment is done, the antibiotic is drained. Then the catheter is flushed clean. The catheter can be used again for nutrition and medicines. This treatment may be repeated over days or weeks.

If the bacteria in your catheter caused an infection in your bloodstream, your doctor will give you separate antibiotics to treat that infection.