Side Effects & Complications of Multiple Myeloma

Multiple myeloma symptoms can vary in intensity and scope, depending on how far the disease has advanced. Also, since myeloma tends to strike at older ages, many people have underlying health problems before the cancer shows itself. Here are some common complications of disease and side effects of treatment.

Bone Pain and Weakness

The most common problems affecting myeloma patients are pain and weakness in the bones. The malignant plasma cells affect the remodeling of bone, causing overproduction of the natural substances that dissolve bone. When plasmacytomas form inside bones, the affected bones can develop soft spots or holes. Although these lesions can affect any bone, pain appears to be most common in the back, ribs and hips. Even seemingly slight movements, such as coughing or turning over in bed, can be painful. Sometimes bones can become so weak they easily fracture.

If the spinal bones become weak, they can collapse and press on nerves in the spine. Patients experiencing sudden and severe pain or numbness should contact their doctor immediately or seek emergency medical help.

When pain adversely affects quality of life, symptoms can be controlled with analgesics or radiation therapy. Drugs are commonly prescribed to delay the deterioration of bone. Unlike medications that alleviate pain directly, drugs for bone loss may take a few weeks to bring relief. Many patients also find that complementary techniques, such as relaxation therapy, acupuncture and massage, can alleviate pain.

Blood Effects

Anemia: More than two-thirds of people with multiple myeloma experience anemia. In the blood, oxygen is carried throughout the body by hemoglobin, which is a protein nestled inside red blood cells. In addition to anemia from the disease, chemotherapy can also impede the production of red blood cells. When the body’s tissues can’t get the oxygen they need, the result is fatigue. The severity of anemia is measured by a patient’s level of hemoglobin. If the hemoglobin is too low, doctors can help manage anemia with a blood transfusion or certain medications.

If a patient’s condition warrants it, erythropoiesis-stimulating agents, or ESAs, may be prescribed to stimulate the production of red blood cells. However, although these drugs are well tolerated, they can be costly and introduce new risks (for example, some studies have suggested they increase the risk of blood clots and, if used inappropriately, may shorten survival time), so the potential benefits and risks must be carefully considered.

Although fatigue is associated with anemia, it can also be a side effect of some medications, stress and other underlying health conditions. Fatigue may be managed through diet (such as taking in more fluids and electrolytes), exercise and by treatment of anemia.

Repeated Infection: Myeloma cells disrupt the balance of the immune system, crowding out white blood cells that normally protect the body from invading viruses and bacteria. Myeloma cells do not produce antibodies to help fight infection, leaving patients vulnerable to serious infections—such as pneumonia—and at risk for bladder and kidney infections, skin infections and shingles. The production of normal white blood cells that help fight infection, including normal plasma cells, is also impeded by chemotherapy. A lower than normal number of white blood cells is called leukopenia. Leukopenia usually resolves following treatment.

Thrombocytopenia and Blood Clots: Some drugs, notably Velcade, might temporarily result in a higher risk of bleeding due to its effects on platelet formation in some patients—particularly those who are taking medications or supplements that interfere with blood clotting. This side effect, known as thrombocytopenia, is temporary in the majority of patients. Conversely, Revlimid and Thalomid treatments increase the risk of venous thromboembolism (the formation of a clot or thrombus in a vein). The chances of venous thromboembolism can be reduced or prevented by adding aspirin to the treatment regimen.

Peripheral Neuropathy

Patients experiencing tingling, numbness or pain in the extremities may have peripheral neuropathy—nerve damage that can be related to the myeloma itself or can occur as a side effect of treatment with Thalomid or Velcade. In the case of Thalomid, some of the damage can be irreversible, so patients should alert their doctor if they start having symptoms while taking the drug. Neuropathy is usually reversible and appears to occur less often in patients who are taking Velcade. If neuropathy develops while taking these drugs, the dosage may be lowered or the treatment discontinued.

Certain medications can help with symptoms, but there are also practical steps that can be taken, such as massaging the feet and exercising regularly.

Kidney Problems

Some patients develop kidney problems even before receiving a diagnosis of multiple myeloma. The kidneys remove waste and excess fluid from the body. Multiple myeloma can damage kidneys, leading to a buildup of salt, fluid and potentially harmful waste products. Sometimes the damage comes from the calcium released as bone tissue dissolves. (High calcium can also cause other symptoms, such as excessive thirst, constipation and even weakness and drowsiness.) Kidneys can also become damaged by the abnormal proteins produced by myeloma cells. As blood filters through the kidneys, the abnormal protein from myeloma cells can latch onto normal protein in urine. The two locked proteins are then too bulky to pass through the kidney’s filtration system. Like clogged pipes, the tubes in the kidneys that filter the blood become more blocked over time.

Early damage often has no symptoms and is generally discovered only through a blood or urine test. Symptoms of advanced kidney disease include itching, swelling in the legs, loss of appetite, fatigue and confusion. Renal problems can become so serious that they are often the cause of death for patients with multiple myeloma, which is why the kidney function is closely monitored during the course of the disease.

Treatment of multiple myeloma will reduce the amount of abnormal protein in the blood and allow the kidneys a chance to heal. It’s also important for patients to stay hydrated and avoid medicines (such as ibuprofen) that can tax the kidneys. If damage to the kidneys is severe, patients may require dialysis or transplantation.

From "A Patient's Guide to Multiple Myeloma," published in the Winter 2011 issue of CURE. Download the full guide here.