Side effects of treatment in multiple myeloma

This paper reviewed the side effects of drugs used in the treatment of multiple myeloma. 

Treatment for multiple myeloma includes different groups of medications. Immunomodulatory drugs work by changing the function of the immune systems. Proteasome inhibitors work by blocking the breakdown of proteins that are needed for cancer growth. Monoclonal antibodies target cancer cells. It is important to understand the negative side effects that may be experienced with each type of therapy.

This review summarized the adverse events (undesired outcome of treatment) associated with these drugs.

Lenalidomide (Revlimid) is an immunomodulatory drug. The most frequent adverse events were blood related. These included low levels of neutrophils (type of white blood cell). One study reported a 30% rate of infections. Long-term lenalidomide therapy may be associated with chronic diarrhea. Lenalidomide is also associated with an increased risk for a second cancer.  Pomalidomide (Imnovid) is another immunomodulatory drug. The most frequent adverse events are low levels of neutrophils, platelets (cells involved in clotting) and red blood cells.  

Bortezomib (Velcade) is a proteasome inhibitor. Adverse events include low levels of neutrophils, platelets and red blood cells. It can also cause nerve damage, diarrhea, constipation, vomiting and fatigue. The dose of bortezomib should be reduced if there is a blood-related adverse event or nerve damage. Patients should receive treatment to prevent viral infections. Carfilzomib (Kyprolis), another proteasome inhibitor, is generally well tolerated. The most common adverse events are low red blood cell levels, fatigue, nausea and diarrhea. The dose of carfilzomib should be changed if there are blood-related adverse events.

Monoclonal antibodies are given through an infusion into the vein. The most frequent adverse reaction are infusion-related reactions. Elotuzumab (Empliciti) is a monoclonal antibody. Adverse events seen with elotuzumab include fatigue, diarrhea, constipation, infections, and weight loss. Daratumumab (Darzalex) is also a monoclonal antibody. About half of patients receiving daratumumab experienced an infusion-related reaction. Other common adverse events are low blood cell counts, fatigue and infections.

Blood clots are a complication of treatment. Patients who are at risk of blood clots should receive medication to prevent blood from clotting. To reduce the risk of infections, patients should be vaccinated. Patients should be regularly monitored for side effects. 

The authors concluded that knowing the side effects of drugs is important to prevent complications.