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Temozolomide Side Effects

In Summary

Commonly reported side effects of temozolomide include: leukopenia. Other side effects include: decreased hemoglobin. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to temozolomide: oral capsule

As well as its needed effects, temozolomide may cause unwanted side effects that require medical attention.

Major Side Effects

If any of the following side effects occur while taking temozolomide, check with your doctor immediately:

Less common or rare:
  • Amnesia
  • black, tarry stools
  • blood in the urine or stools
  • convulsions
  • cough or hoarseness
  • fever or chills
  • lower back or side pain
  • muscle weakness or paralysis on one or both sides of the body
  • painful or difficult urination
  • pinpoint red spots on the skin
  • swelling of the feet or lower legs
  • unusual bleeding or bruising
Incidence not known:
  • Abdominal or stomach pain or tenderness
  • blistering, peeling, or loosening of the skin
  • chest pain
  • clay colored stools
  • cough
  • decreased appetite
  • diarrhea
  • difficulty swallowing
  • dizziness
  • fast heartbeat
  • headache
  • hives, itching, or skin rash
  • joint or muscle pain
  • nausea or vomiting
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • sneezing
  • sore throat
  • sores, ulcers, or white spots in the mouth or on the lips
  • tightness in the chest
  • troubled breathing
  • unusual tiredness or weakness
  • yellow skin or eyes

Minor Side Effects

Some temozolomide side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common:
  • Constipation
Less common or rare:
  • Anxiety
  • blurred or double vision
  • breast pain (in females)
  • burning or prickling feeling on the skin
  • confusion
  • diarrhea
  • difficulty with speaking
  • drowsiness
  • increased urge to urinate
  • loss of appetite
  • loss of muscle coordination
  • mental depression
  • runny or stuffy nose
  • trouble sleeping
  • unusual weight gain

For Healthcare Professionals

Applies to temozolomide: intravenous powder for injection, oral capsule


Very common (10% or more): Constipation (Up to 33%), nausea (Up to 53%), vomiting (Up to 42%), diarrhea (16%)
Common (1% to 10%): Abdominal pain, diarrhea, stomatitis, taste perversion, dysphagia, dyspepsia
Uncommon (0.1% to 1%): Abdominal distension, fecal incontinence, gastrointestinal disorder, gastroenteritis, hemorrhoids[Ref]


The most common side effects were alopecia, nausea, vomiting, anorexia, headache, and constipation.[Ref]

Nervous system

Very common (10% or more): Headache (Up to 41%), convulsions (Up to 23%), hemiparesis (18%), abnormal coordination (11%)
Common (1% to 10%): Dizziness, confusion, memory impairment, amnesia, paresthesia, somnolence, paresis, urinary incontinence, ataxia, abnormal gait, neuropathy, balance impairment, speech disorder, tremors, hemiparesis[Ref]


Very common (10% or more): Peripheral edema (11%)
Uncommon (0.1% to 1%): Palpitation[Ref]


Very common (10% or more): Fatigue (Up to 61%), asthenia (13%), fever (13%)
Common (1% to 10%): Weakness, radiation injury, face edema, pain, hearing impairment
Uncommon (0.1% to 1%): Otitis media, tinnitus, hyperacusis, earache, deafness, vertigo, impotence, vaginal hemorrhage, menorrhagia, amenorrhea, vaginitis, breast pain[Ref]


Common (1% to 10%): Adrenal hypercorticism[Ref]


Common (1% to 10%): Cough, dyspnea, upper respiratory tract infection, pharyngitis, sinusitis
Post-marketing surveillance: Interstitial pneumonitis, pneumonitis, alveolitis, pulmonary fibrosis[Ref]


A case of diffuse erythematous skin rash that progressed to an extensive full body desquamative skin rash has been reported. Even though temozolomide was permanently discontinued, the patient continued to experience the rash on a long-term basis with periodic exacerbations.[Ref]

Very common (10% or more): Alopecia (55 to 69%), rash (13 to 19%)
Common (1% to 10%): Dry skin, erythema, pruritus, petechiae
Uncommon (0.1% to 1%): Photosensitivity reaction, abnormal pigmentation, sweating increased
Post-marketing surveillance: Toxic epidermal necrolysis, Stevens-Johnson syndrome[Ref]


Common (1% to 10%): Insomnia, anxiety, depression
Uncommon (0.1% to 1%): Agitation, apathy, behavior disorder, hallucination, amnesia[Ref]


Very common (10% or more): Anorexia (19 to 27%)
Common (1% to 10%): Weight increase, weight decrease, hyperglycemia
Uncommon (0.1% to 1%): Hypokalemia[Ref]


Common (1% to 10%): Arthralgia, back pain[Ref]


Common (1% to 10%): Vision blurred, diplopia
Uncommon (0.1% to 1%): Hemianopia, visual acuity reduced, vision disorder, visual field defect, eye pain, dry eyes[Ref]


Common (1% to 10%): Infection, Herpes simplex, wound infection, candidiasis oral
Uncommon (0.1% to 1%): Herpes zoster, influenza-like symptoms
Post-marketing surveillance: Opportunistic infections including Pneumocystis pneumonia[Ref]


Post-marketing surveillance: Secondary malignancies including myeloid leukemia[Ref]


Common (1% to 10%): Thrombocytopenia, hemorrhage, leukopenia, neutropenia, lymphopenia, febrile neutropenia, anemia
Post-marketing surveillance: Prolonged pancytopenia, myelodysplastic syndrome[Ref]


Common (1% to 10%): ALT increased
Uncommon (0.1% to 1%): Hepatic enzymes increased, Gamma GT increased, AST increased
Post-marketing surveillance: Fatal and severe hepatotoxicity, elevation of liver enzymes, hyperbilirubinemia, cholestasis, hepatitis


Common (1% to 10%): Allergic reaction


Common (1% to 10%): Urinary tract infection, micturition increased frequency
Uncommon (0.1% to 1%): Dysuria


1. "Product Information. Temodar (temozolomide)" Schering Corporation, Kenilworth, NJ.

2. Pick AM, Neff WJ, Nystrom KK "Temozolomide-induced desquamative skin rash in a patient with metastatic melanoma." Pharmacotherapy 28 (2008): 406-9

3. Villano JL, Collins CA, Manasanch EE, Ramaprasad C, van Besien K "Aplastic anaemia in patient with glioblastoma multiforme treated with temozolomide." Lancet Oncol 7 (2006): 436-8

It is possible that some side effects of temozolomide may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

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.