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Gemtuzumab Side Effects

For the Consumer

Applies to gemtuzumab: intravenous powder for solution

Along with its needed effects, gemtuzumab 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 gemtuzumab:

More Common

  • Bleeding gums
  • blood in the urine or stools
  • bone pain
  • chest pain
  • chills
  • confusion
  • cough
  • coughing up blood
  • decreased urine output
  • difficulty in breathing or swallowing
  • dizziness, lightheadedness, or fainting
  • dry mouth
  • fast or irregular heartbeat
  • fever
  • headache
  • hoarseness
  • increased menstrual flow or vaginal bleeding
  • increased thirst
  • irregular heartbeat
  • loss of appetite
  • loss of consciousness
  • lower back or side pain
  • mood changes
  • muscle pain or cramps
  • nausea
  • nosebleeds
  • numbness or tingling in the hands, feet, or lips
  • painful or difficult urination
  • paralysis
  • pinpoint red spots on the skin
  • prolonged bleeding from cuts
  • rapid, shallow breathing
  • rash
  • red or black, tarry stools
  • red or dark brown urine
  • seizures
  • sore throat
  • swelling of the face, ankles, or hands
  • tightness in the chest
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting

Less Common

  • Blue lips and fingernails
  • coughing that sometimes produces a pink frothy sputum
  • difficult, fast, noisy breathing
  • fast, pounding, or irregular heartbeat or pulse
  • increased sweating
  • pale skin
  • right upper abdominal pain and fullness
  • stomach pain and bloating
  • ulcers, sores, or white spots in the mouth

Incidence Not Known

Some side effects of gemtuzumab 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

Less Common

  • Cracked lips

For Healthcare Professionals

Applies to gemtuzumab: intravenous powder for injection


Very common (10% or more): Bleeding (25%), thrombocytopenia (24%), febrile neutropenia (18%)

Common (1% to 10%): Hemorrhage

Frequency not reported: Myelosuppression, anemia[Ref]


Very common (10% or more): Fever (79%), fatigue (46%)

Common (1% to 10%): Pain

Frequency not reported: Chills[Ref]


Very common (10% or more): Nausea (21%), vomiting (21%), constipation (21%), mucositis (21%)

Common (1% to 10%): Diarrhea

Postmarketing reports: Neutropenic colitis (sometimes fatal)[Ref]


Common (1% to 10%): Pneumonia, lung edema

Frequency not reported: Hypoxia, respiratory failure, dyspnea

Postmarketing reports: Fungal lung infections (including Pulmonary mycosis and Pneumocystis jirovecii pneumonia) (sometimes fatal), interstitial pneumonia (sometimes fatal)[Ref]


Very common (10% or more): Increased AST (40%), increased ALT (16%)

Common (1% to 10%): Veno-occlusive liver disease (VOD) (sometimes fatal), hyperbilirubinemia[Ref]


Postmarketing reports: Hemorrhagic cystitis (sometimes fatal)

Genitourinary side effects have included vaginal hemorrhage (12%) and hematuria (10%)[Ref]


Very common (10% or more): Infection (44%), sepsis (32%)

Postmarketing reports: Bacterial infections (including Stenotrophomonas infection), potential for immunogenicity[Ref]


Frequency not reported: Renal failure secondary to tumor lysis syndrome[Ref]


Common (1% to 10%): Tachycardia

Frequency not reported: QT interval prolongation, hypotension[Ref]


Very common (10% or more): Rash (16%)[Ref]

Nervous system

Very common (10% or more): Headache (19%)[Ref]


Very common (10% or more): Hypophosphatemia (64%), hypokalemia (57%), hyponatremia (44%), alkaline phosphatase increased (13%), aspartate aminotransferase increased (14%), alanine aminotransferase increased (10%)

Common (1% to 10%): Blood bilirubin increased[Ref]


Frequency not reported: Hypersensitivity (including anaphylaxis)[Ref]


1. "Product Information. Mylotarg (gemtuzumab)" Wyeth-Ayerst Laboratories, Philadelphia, PA.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.