Treating Multiple Myeloma: Common Side Effects to Watch Out For

Before starting treatment for multiple myeloma—a cancer of the plasma cell, which is a type of white blood cell made in the bone marrow—it’s important to be aware of the side effects you may experience. Knowing how certain therapies will affect your life can help you find the treatment plan that’s right for you.

Here are the main treatments for multiple myeloma and the side effects that may occur: 

Chemotherapy kills cancer cells but can also damage normal, healthy cells. “It’s the high-dose chemotherapy that treats the myeloma, and then we use stem cells to help you recover quickly,” says Adriana Rossi, MD, associate clinical director of the Myeloma Center at Weill Cornell Medicine and NewYork-Presbyterian. 

Common side effects of chemo may include: 

• Hair loss

• Mouth sores

• Loss of appetite

• Nausea and vomiting

• And low blood counts.

Stem cell (bone marrow) transplantation. “We use stem cells that come from the bone marrow, and we now collect them through an IV in your arm to help you recover from high-dose chemotherapy,” says Dr. Rossi. “With a stem cell transplant, we’re really rebooting the immune system.” 

A stem cell transplant can be done using the patient’s own stem cells (autologous transplantation) or from a donor (allogeneic transplantation). In multiple myeloma, most transplants are performed using the patient’s own stem cells.

 Some side effects of stem cell transplants may include: 

• Fatigue

• Mouth and throat pain

• Nausea and vomiting 

• Infections

• Bleeding

• And lung problems, such as pneumonia. 

Corticosteroids (steroids) are an important part of the treatment of multiple myeloma. “They really enhance the response to every other drug that we use,” says Dr. Rossi. 

Common side effects of these drugs may include:

• High blood sugar

• Increased appetite and weight gain

• Problems sleeping

• Changes in mood (some people become irritable or “hyper”)

• Weakening of the bones

• And a suppressed immune system.

Most of these side effects go away over time after the patient stops taking the medicine. 

Proteasome inhibitors work by stopping enzyme complexes (proteasomes) in cells from breaking down proteins that are important for cell division. “Proteasome inhibitors are very commonly used and generally well tolerated,” says Dr. Rossi. 

However, this treatment may cause: 

• Nerve damage (peripheral neuropathy)

• Constipation

• And low platelet counts.

Monoclonal antibodies are a type of immunotherapy. “Monoclonal antibodies are the newest class of drugs that we have in myeloma and they’re incredibly well tolerated,” says Dr. Rossi. Monoclonal antibodies treat multiple myeloma by attacking specific substances (antigens) on the surface of the cancer cells.

“Other than an allergic reaction, usually to the first dose, there are very few side effects,” says Dr. Rossi. 

If you begin to experience side effects, your cancer care team can help. “It’s very important to maintain close communication with your physician, especially during that first cycle of new therapy, as your body gets used to not only the treatments, but [also] the other medicines that we use to prevent side effects,” says Dr. Rossi. “[If] a treatment either stops working or has side effects that the patient finds intolerable, that’s a reason for us to find a new line of therapy.”