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Alemtuzumab Side Effects

In Summary

Commonly reported side effects of alemtuzumab include: herpes simplex infection, opportunistic infection, and thrombocytopenia. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to alemtuzumab: intravenous solution


Intravenous route (Solution)

Serious, sometimes fatal autoimmune conditions including immune thrombocytopenia and antiglomerular basement membrane disease may occur. Complete blood counts with differential, serum creatinine levels, and urinalysis with urine cell counts should be monitored at periodic intervals for 48 months after discontinuing therapy. Serious and life-threatening infusion reactions have been reported and can occur after the 2-hour monitoring period. Administer in a setting appropriate for managing anaphylaxis or serious infusion reactions. Alemtuzumab may increase the risk of malignancies including thyroid cancer, melanoma, and lymphoproliferative disorders. Baseline and yearly skin exams are recommended. Because of the risks associated with alemtuzumab, it is only available through restricted distribution under a Risk Evaluation Mitigation Strategy (REMS) program.

Along with its needed effects, alemtuzumab 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 alemtuzumab:

More Common

  • Black, tarry stools
  • blood in the urine
  • chills
  • cough
  • diarrhea
  • dizziness
  • faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • fast heartbeat
  • fever
  • headache
  • itching, hives, or rash
  • nausea
  • painful or difficult urination
  • pale skin
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • sweating
  • swollen glands
  • tightness in the chest
  • troubled breathing, exertional
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting

Less Common

  • Bloating or swelling of the face, hands, lower legs, or feet
  • chest pain
  • hoarseness
  • lower back or side pain
  • muscle weakness
  • pounding, or irregular heartbeat or pulse
  • rapid weight gain
  • red or purple spots on the skin, varying in size and remaining after pushing the skin surface


  • Flushing of the face or neck
  • swelling of the eyelids, face, or lips
  • white patches on the tongue, in the mouth, or in the folds of the skin, including the genitals

Incidence Not Known

  • Back pain
  • blindness
  • blurred vision
  • chest discomfort
  • confusion
  • decreased urine output
  • decreased vision
  • dilated neck veins
  • drowsiness
  • extreme tiredness or weakness
  • eye pain
  • feeling of discomfort
  • inability to move the arms and legs
  • inflammation of the joints
  • irregular breathing
  • joint pain, stiffness, or swelling
  • muscle aches or pain
  • numbness, pain, tingling, or weakness
  • painful glands
  • seizures
  • spitting up blood
  • sudden numbness and weakness in the arms and legs
  • swelling of the face, fingers, feet, or lower legs

Some side effects of alemtuzumab 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

  • Fear or nervousness
  • trouble sleeping

Less Common

  • Belching
  • bone pain
  • burning, crawling, itching, numbness, prickling, “pins and needles”, or tingling feelings
  • heartburn
  • indigestion
  • lack or loss of strength
  • loss of appetite
  • painful cold sores or blisters on the lips, nose, eyes, or genitals
  • stomach discomfort, upset, or pain
  • swelling or inflammation of the mouth
  • weight loss


  • Bloody nose
  • constipation
  • sensation of temperature change
  • sleepiness
  • stuffy nose
  • tremor
  • unexplained nosebleeds

For Healthcare Professionals

Applies to alemtuzumab: intravenous solution


Very common (10% or more): Lymphopenia (97%), neutropenia (77%), anemia (76%), thrombocytopenia (71%), granulocytopenia

Common (1% to 10%): Decrease in CD4 lymphocytes, decrease in CD8 lymphocytes, decrease in T-lymphocyte count, febrile neutropenia, pancytopenia, leukopenia, lymphopenia, purpura

Uncommon (0.1% to 1%): Aplasia bone marrow, disseminated intravascular coagulation, hemolytic anemia, decreased haptoglobin, bone marrow depression, hematology test abnormal[Ref]


Very common (10% or more): Immunogenicity (up to 83%), herpes viral infection (16%), fungal infection (13%), sepsis, cytomegalovirus infection, cytomegalovirus


Common (1% to 10%): Influenza, neutropenic fever

Uncommon (0.1% to 1%): Sepsis, staphylococcal bacteremia, tuberculosis, beta hemolytic streptococcal infections, candidiasis, genital candidiasis, body tinea

Very rare (less than 0.01%): Immune thrombocytopenia

Frequency not reported: Autoimmunity[Ref]


Very common (10% or more): Nasopharyngitis (25%), upper respiratory tract infection (16%), sinusitis (11%), pneumonia

Common (1% to 10%): Cough, dyspnea, bronchitis, chest discomfort, epistaxis, hypoxia, hemoptysis, bronchospasm

Uncommon (0.1% to 1%): Stridor, throat tightness, pulmonary infiltration, pleural effusion, breath sounds decreased, respiratory disorder

Frequency not reported: Respiratory alkalosis[Ref]


Very common (10% or more): Nausea (21%), diarrhea (12%), oropharyngeal pain (11%), abdominal pain (10%), vomiting (10%)

Common (1% to 10%): Dyspepsia, gastrointestinal hemorrhage, ulcerative stomatitis, stomatitis, gastroenteritis, tongue ulceration, gingivitis, hiccup, eructation, dyspepsia, constipation, flatulence, oral candidiasis

Uncommon (0.1% to 1%): Gingival bleeding, dry mouth, paralytic ileus, oral discomfort

Frequency not reported: Duodenal ulcer, intestinal perforation, melena, peptic ulcer, pseudomembranous colitis, colitis, pancreatitis, peritonitis[Ref]

Nervous system

Very common (10% or more): Headache (52%), insomnia (16%), paresthesia (10%), dizziness (10%)

Common (1% to 10%): Dysgeusia, vertigo, tremor, paresthesia, hypoesthesia, hyperkinesia, taste loss

Uncommon (0.1% to 1%): Syncope, abnormal gait, dystonia, hyperesthesia, neuropathy, taste perversion[Ref]


Very common (10% or more): Hypotension, hypertension

Common (1% to 10%): Tachycardia, peripheral edema, vasospasm

Uncommon (0.1% to 1%): Cardiac arrest, myocardial infarction, atrial fibrillation, supraventricular tachycardia, arrhythmia, bradycardia, abnormal ECG, peripheral ischemia, cyanosis, orthostatic hypotension, hot flush

Frequency not reported: Congestive heart failure, cardiomyopathy, decreased ejection fraction in non-MS patients previously treated with potentially cardiotoxic agents[Ref]


Very common (10% or more): Arthralgia (12%), pain in extremity (12%), back pain (12%)

Common (1% to 10%): Chills, muscular weakness, muscle spasms, myalgia, neck pain, arthralgia, skeletal pain, back pain

Uncommon (0.1% to 1%): Leg pain, hypertonia, muscle spasms

Frequency not reported: Arthritis or worsening arthritis, bone fracture, myositis, muscle atrophy, osteomyelitis, polymyositis, skeletal pain[Ref]


Very common (10% or more): Rash (53%), urticaria (16%), pruritus (14%)

Common (1% to 10%): Dermatitis, erythema, hyperhidrosis, bullous eruption, erythematous rash

Uncommon (0.1% to 1%): Maculopapular rash, skin disorder[Ref]


Very common (10% or more): Thyroid gland disorders (13%)[Ref]


Frequency not reported: Hyperbilirubinemia, hepatic failure, hepatocellular damage, hypoalbuminemia, biliary pain[Ref]


Very common (10% or more): Anorexia

Common (1% to 10%): hyponatremia, hypocalcemia, weight decrease, dehydration, thirst

Uncommon (0.1% to 1%): Hypokalemia, diabetes mellitus aggravated

Frequency not reported: Thyroid disorder, fluid overload[Ref]


Frequency not reported: Malignancies (e.g., malignant lymphoma, malignant testicular neoplasm, prostatic cancer, plasma cell dyscrasias, secondary leukemia, squamous cell carcinoma)[Ref]


Very common (10% or more): Urinary tract infection (19%)

Common (1% to 10%): Blood in urine, abnormal uterine bleeding

Uncommon (0.1% to 1%): Impotence, urinary incontinence, urine flow decreased, polyuria, cystitis

Frequency not reported: Cervical dysplasia[Ref]


Very common (10% or more): Pyrexia (29%), fatigue (18%), flushing (10%)

Common (1% to 10%): Asthenia[Ref]


Uncommon (0.1% to 1%): Renal function abnormal

Frequency not reported: Acute renal failure[Ref]


Common (1% to 10%): Conjunctivitis

Uncommon (0.1% to 1%): Endophthalmitis[Ref]


Uncommon (0.1% to 1%): Allergic reaction

Frequency not reported: Anaphylactoid reaction[Ref]


Uncommon (0.1% to 1%): Infusion site bruising, infusion site dermatitis, infusion site pain

Frequency not reported: Infusion reactions[Ref]


1. "Product Information. Campath (alemtuzumab)" Berlex, Richmond, CA.

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

3. Cerner Multum, Inc. "Australian Product Information." O 0

4. Poynton CH, Mort D, Maughan TS "Adverse reactions to Campath-1H monoclonal antibody [letter; comment]." Lancet 341 (1993): 1037

5. Rai KR, Freter CE, Mercier RJ, et al. "Alemtuzumab in previously treated chronic lymphocytic leukemia patients who also had received fludarabine." J Clin Oncol 20 (2002): 3891-7

6. Ghobrial IM, Otteman LA, White WL "An EBV-positive lymphoproliferative disorder after therapy with alemtuzumab." N Engl J Med 349 (2003): 2570-2; discussion 2570-2

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.