What Are the Effects of Combining Fludarabine and Rituximab?

Fludarabine and rituximab are two medications that may be prescribed together to treat blood cancers, given their dual effect. Continuing research on using the two drugs together shows that when they are combined, they have proven more useful to treat certain types of cancer, particularly blood cancers like chronic lymphocytic leukemia (CLL). Their effect when used together is called “synergistic,” which means they tend to provide a greater pronounced positive effect when combined than when either of the two drugs is used alone. While this can be positive, the use of both medications also elevates risks of certain side effects.

Rituximab has been found useful in certain blood cancers because it can reduce the count of some blood cells that may accelerate disease. Injected or infused fludarabine accomplishes several things. It tends to retard cell growth and by impairing DNA and RNA growth, it often causes cell death.

These different actions inspired medical researchers to begin testing the efficacy of using fludarabine and rituximab in combination. Since the early 2000s, small trials showed positive results as a treatment for CLL. For example, a 2006 study showed fludarabine and rituximab to be between 30-70% effective in extending life.

Some of the most telling studies on the benefits of fludarabine and rituximab were published in 2011. Long analysis of many small studies finds that the two drugs significantly increase survival rates for those with CLL. In other words, much longer-term remission from CLL is achieved for many people who are given this combined treatment.

Fludarabine and rituximab aren’t always used alone. Depending on the condition or the patient’s response, other drugs might be used, also. For example, other chemo- or immunotherapy medications could be part of treatment. Generally, though, these two drugs are now considered the gold standard treatment for CLL, though this may be subject to change due to additional research.

Using fludarabine and rituximab has some demonstrated side effects, too. Patients given both medications are more likely to develop low blood pressure. The drugs can also cause neutropenia, a dangerously low level of white blood cells. Doctors watch for these adverse reactions carefully, and might adjust medications or recommend new treatments if they occur.

The two drugs may also interfere with other medications, particularly drugs like blood thinners or anticoagulants. Additionally, their use may not be recommended during pregnancy or if patients have certain other medical conditions. Patients are advised to discuss with their physicians the medications they use and any ongoing medical conditions prior to accepting treatment with fludarabine and rituximab.