Treatment Side Effects

Core Conclusion

Antimyeloma regimens have manageable side effects: subcutaneous bortezomib reduces peripheral neuropathy to under 20%, and daily low-dose aspirin (81 to 100 mg) or anticoagulation lowers IMiD thrombosis risk by more than 80%.

Detailed Points

(1) Bortezomib (Velcade): Peripheral Neuropathy

• What it is: Bortezomib can cause damage to the nerves (peripheral neuropathy), which produces numbness, tingling, and pain that typically starts in your toes or fingertips and can feel like you are wearing tight stockings or gloves.
• Subcutaneous vs. IV: Getting this medication as a subcutaneous (under the skin) injection is the strongly preferred method of administration. Clinical trials have proven that giving the drug under the skin significantly reduces the rate of severe (Grade >= 3) neuropathy down to just 6%, compared to 16% when given intravenously (IV).
• Management & Interventions: The most important thing you can do is notify your doctor at the very first sign of tingling. They can easily adjust your dose or switch you to a once-weekly dosing schedule (which is preferred and safer) to prevent the nerve damage from getting worse.

(2) Lenalidomide (Revlimid): Thrombosis and Low Blood Counts

• Thrombosis Risk: This drug carries a "black box" warning because it increases your risk for dangerous blood clots in your veins or arteries.

  • Management: You must use "risk-adapted thromboprophylaxis". At the very least, you will need to take a baby aspirin every single day. If you have a higher risk of clots, your doctor will prescribe a stronger injectable (like Lovenox) or oral blood thinner (like Eliquis or Xarelto).
• Myelosuppression (Low Blood Counts): Lenalidomide can lower your white blood cells and platelets, putting you at risk for bleeding or infections. Severe (Grade >= 3) drops in white blood cells (neutropenia) can occur in roughly 29.5% to 41% of patients.

  • Management: Your doctor will monitor your blood work closely and may give you growth factors (like Neupogen) or prophylactic antibiotics to help protect you.
• Emergency Warning Signs: Seek emergency medical care immediately if you develop sudden shortness of breath or leg swelling (signs of a blood clot), or if you experience a fever over 100.5°F, chills, or sweating, which are critical signs of infection.

(3) Dexamethasone (Steroids): Blood Sugar and Discomfort

• What it is: Steroids are a powerful backbone of myeloma treatment but can cause frustrating side effects, including sleep disruptions, stomach discomfort, and significant changes in your blood sugar levels.
• Management & Interventions: Your doctor will monitor your blood sugar closely and may prescribe medications to protect your stomach. To minimize toxicity—especially for older or frail patients—guidelines recommend reducing the dexamethasone dose to 20 mg weekly. The dose can also be decreased or safely discontinued once your treatment response reaches a plateau.
• Emergency Warning Signs: Never stop or adjust your steroid dose on your own without talking to your doctor. Reach out to your team if you experience severe stomach pain or signs of extremely high blood sugar (like unquenchable thirst or frequent urination).

(4) Daratumumab (Darzalex): Infusion-Related Reactions

• What it is: Because this drug is an antibody, your immune system can overreact to it. Infusion-related reactions—such as chills, fever, nausea, cough, or rash—are very common, occurring in about 47.7% of patients receiving the IV form.
• Management & Interventions: To protect you, your nurses will give you premedications (like antihistamines and Tylenol) before and after your administration to drastically reduce your risk of a reaction. Additionally, the newer subcutaneous injection form of this drug (Darzalex Faspro) is now widely used because it results in significantly fewer infusion-related reactions compared to the traditional IV drip.
• Emergency Warning Signs: Although rare, severe reactions such as difficulty breathing or a sudden drop in low blood pressure can occur. If you feel your throat tightening or become dizzy during or after your appointment, alert a healthcare professional immediately.

The above content is sourced from the following references

• Br J Haematol - 2025 - Jenner - Management of relapsed multiple myeloma A British Society of Haematology and UK Myeloma Society guideline
• Patient Handbook
• MMRF-Newly-Diagnosed-MM_patient-toolkit
• MMRF-Treatment-Overview_patient-toolkit
• NCCN Guidelines Version 5.2026 Multiple Myeloma