Tositumomab Side Effects

Some side effects of tositumomab may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

For the Consumer

Applies to tositumomab: intravenous solution

Along with its needed effects, tositumomab may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking tositumomab:

More common
  • Bleeding gums
  • bloating or swelling of the face, arms, hands, lower legs, or feet
  • blurred vision
  • bone pain
  • chest pain
  • chills
  • confusion
  • constipation
  • cough
  • coughing up blood
  • depressed mood
  • difficulty with breathing
  • difficulty with swallowing
  • dizziness
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • dry skin and hair
  • fast heartbeat
  • feeling cold
  • fever or chills
  • hair loss
  • headache
  • hives
  • hoarseness or husky voice
  • increased menstrual flow or vaginal bleeding
  • itching
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • lower back or side pain
  • muscle cramps and stiffness
  • noisy breathing
  • nosebleeds
  • painful or difficult urination
  • pale skin
  • paralysis
  • pinpoint red spots on the skin
  • prolonged bleeding from cuts
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • rapid weight gain
  • red or black, tarry stools
  • red or dark brown urine
  • shortness of breath
  • skin rash
  • slowed heartbeat
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • sweating
  • swollen glands
  • tightness in the chest
  • tingling of the hands or feet
  • troubled breathing with exertion
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • unusual weight gain or loss
  • wheezing
Less common
  • Feeling of warmth or heat
  • flushing or redness of the skin, especially on the face and neck

Some side effects of tositumomab may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common
  • Acid or sour stomach
  • back pain
  • belching
  • body aches or pain
  • congestion
  • diarrhea or increased bowel movements
  • difficult or labored breathing
  • difficulty with moving
  • dryness or soreness of the throat
  • heartburn
  • indigestion
  • itching skin
  • joint pain
  • lack or loss of strength
  • loose or liquid stools
  • loss of appetite
  • muscle aches or pains
  • nausea or feeling of upset stomach or feeling like you may vomit
  • neck pain
  • runny nose
  • stomach discomfort, upset, or pain
  • sudden sweating
  • swelling of the hands, ankles, feet, or lower legs
  • swollen joints
  • tender, swollen glands in the neck
  • trouble with swallowing
  • voice changes
  • vomiting
  • weight loss
Less common
  • Sleepiness or unusual drowsiness

For Healthcare Professionals

Applies to tositumomab: intravenous kit


Common (1% to 10%): Hypotension, vasodilation


Very common (10% or more): Rash, pruritus
Common (1% to 10%): Sweating


Common (1% to 10%): Hypothyroidism


Very common (10% or more): Abdominal pain, nausea, vomiting, diarrhea, anorexia
Common (1% to 10%): Constipation, dyspepsia


Very common (10% or more): Neutropenia, thrombocytopenia, anemia


Common (1% to 10%): Allergic (hypersensitivity) reactions (allergic reaction, facial edema, injection site hypersensitivity, anaphylactic reaction, laryngismus, serum sickness)
Postmarketing reports: Hypersensitivity reactions including fatal anaphylaxis


Very common (10% or more): Positive serology for human anti-mouse antibodies (HAMA)


Frequency not reported: Infusion reactions


Common (1% to 10%): Peripheral edema, weight loss


Very common (10% or more): Myalgia, arthralgia
Common (1% to 10%): Back pain, neck pain

Nervous system

Common (1% to 10%): Dizziness, somnolence
Postmarketing reports: Axonal neuropathy leading to quadriparesis


Common (1% to 10%): Secondary malignancies (non-melanoma skin, colorectal, head and neck, breast, lung, bladder, melanoma, gastric)
Frequency not reported: Secondary leukemia, myelodysplastic syndrome


Very common (10% or more): Asthenia, fever, infections, pain, chills, headache
Common (1% to 10%): Chest pain, serious infections (pneumonia, bacteremia, septicemia, bronchitis, skin infections)


Very common (10% or more): Cough, pharyngitis, dyspnea, rhinitis
Common (1% to 10%): Pneumonia

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.