Temodal: Uses, Dosage & Side Effects

An oral alkylating chemotherapy agent used to treat glioblastoma multiforme and other malignant brain tumors (gliomas) in adults and children over 3 years of age

Rx ATC: L01AX03 Alkylating Agent
Active Ingredient
Temozolomide
Available Forms
Hard capsules (oral)
Strengths
5 mg, 20 mg, 100 mg, 140 mg, 180 mg, 250 mg
Manufacturer
Merck Sharp & Dohme (MSD)

Temodal (temozolomide) is an oral alkylating chemotherapy drug used to treat specific types of malignant brain tumors. It is the standard of care for newly diagnosed glioblastoma multiforme (GBM) in adults, where it is given concurrently with radiotherapy and then as maintenance monotherapy. Temodal is also approved for recurrent or progressive malignant glioma, including glioblastoma and anaplastic astrocytoma, in both adults and children older than 3 years. Temozolomide is unique among chemotherapy agents because it crosses the blood-brain barrier effectively, allowing it to reach tumor cells within the central nervous system. It is available as hard capsules in multiple strengths and requires a prescription from a specialist physician.

Quick Facts: Temodal

Active Ingredient
Temozolomide
Drug Class
Alkylating Agent
ATC Code
L01AX03
Common Uses
Glioblastoma & Glioma
Available Forms
Hard Capsules
Prescription Status
Rx Only

Key Takeaways

  • Temodal (temozolomide) is the standard chemotherapy for newly diagnosed glioblastoma multiforme (GBM), given alongside radiotherapy for 42 days and then as maintenance therapy for up to 6 cycles of 28 days each.
  • The drug crosses the blood-brain barrier effectively, achieving therapeutic concentrations in the central nervous system at approximately 30–40% of plasma levels, making it uniquely suited for treating brain tumors.
  • Myelosuppression (reduced blood cell counts) is the most significant side effect; regular blood tests are mandatory throughout treatment, and prophylaxis against Pneumocystis jirovecii pneumonia (PCP) is required during the concurrent phase with radiotherapy.
  • Capsules must be taken on an empty stomach, swallowed whole with water; the dose is calculated based on body surface area (mg/m²), and patients may need to combine multiple capsule strengths to achieve the prescribed dose.
  • Temozolomide can cause permanent infertility in males; men should consider sperm cryopreservation before treatment, and both men and women must use effective contraception during and after therapy.

What Is Temodal and What Is It Used For?

Quick Answer: Temodal (temozolomide) is an oral chemotherapy drug that belongs to the alkylating agent class. It is used to treat malignant brain tumors, primarily glioblastoma multiforme (GBM) and anaplastic astrocytoma, by damaging the DNA of cancer cells and triggering cell death.

Temodal contains the active substance temozolomide, an imidazotetrazine derivative that functions as a prodrug. After oral administration, temozolomide is rapidly absorbed and spontaneously converts at physiological pH (the normal acidity level of the body) to its active form, MTIC (5-(3-methyltriazen-1-yl)imidazole-4-carboxamide). This conversion does not require enzymatic activation by the liver, which distinguishes temozolomide from many other chemotherapy agents and contributes to its consistent pharmacological activity.

Once formed, MTIC acts by adding methyl groups (small chemical tags) to the DNA of cells, a process known as alkylation. The primary target is the O6 position of guanine, one of the four building blocks of DNA. When a methyl group is attached to this position, it causes the DNA to mismatch during replication, leading to futile repair cycles, DNA strand breaks, and ultimately programmed cell death (apoptosis). This mechanism is particularly effective against rapidly dividing tumor cells.

A critically important factor in the effectiveness of temozolomide is the status of the MGMT (O6-methylguanine-DNA methyltransferase) gene in the tumor. MGMT is a DNA repair enzyme that can remove the methyl groups that temozolomide adds to DNA, essentially undoing the drug's work. In tumors where the MGMT gene promoter is methylated (silenced), the cancer cells produce less of this repair enzyme and are therefore more susceptible to temozolomide. Testing for MGMT promoter methylation status has become a standard part of the diagnostic workup for glioblastoma, as it provides important prognostic information and helps guide treatment decisions.

One of the most important properties of temozolomide is its ability to cross the blood-brain barrier (BBB). The blood-brain barrier is a highly selective membrane that protects the brain from potentially harmful substances in the bloodstream, but it also prevents many chemotherapy drugs from reaching brain tumors. Temozolomide achieves concentrations in the cerebrospinal fluid (CSF) that are approximately 30–40% of plasma levels, which is exceptionally high for a chemotherapy agent and makes it one of the few truly effective systemic treatments for primary brain tumors.

Temodal is approved by the European Medicines Agency (EMA), the U.S. Food and Drug Administration (FDA, marketed as Temodar), and regulatory authorities worldwide for the following indications:

  • Newly diagnosed glioblastoma multiforme (GBM) in adults: Temodal is used first in combination with radiotherapy (the concurrent phase, lasting up to 42–49 days at 75 mg/m² daily) and then alone as maintenance therapy (the monotherapy phase, for up to 6 cycles of 28 days). This protocol, known as the Stupp regimen after the landmark 2005 clinical trial published in the New England Journal of Medicine, demonstrated a significant improvement in overall survival compared with radiotherapy alone and established temozolomide as the standard of care for newly diagnosed GBM.
  • Recurrent or progressive malignant glioma in children (older than 3 years) and adults: This includes glioblastoma multiforme and anaplastic astrocytoma that has returned or continued to grow after standard treatment. In this setting, Temodal is used as monotherapy in 28-day cycles.

Glioblastoma multiforme is the most aggressive and most common primary malignant brain tumor in adults. It is classified as a grade 4 glioma by the World Health Organization (WHO) and is characterized by rapid growth, extensive infiltration of surrounding brain tissue, and a tendency to recur despite treatment. Even with optimal therapy combining surgery, radiotherapy, and temozolomide chemotherapy, the median overall survival for patients with newly diagnosed GBM remains approximately 14–16 months, underscoring the need for continued research and new therapeutic approaches. Anaplastic astrocytoma is a grade 3 glioma that, while less aggressive than GBM, can also be challenging to treat and may progress to GBM over time.

MGMT Methylation Status

Your doctor may test your tumor for MGMT promoter methylation status. Patients whose tumors have a methylated (silenced) MGMT promoter tend to respond better to temozolomide treatment and generally have better outcomes. However, temozolomide is still offered to patients with unmethylated MGMT promoters, as it remains the standard of care and some benefit is still observed. The MGMT status helps guide expectations and may influence decisions about participating in clinical trials.

What Should You Know Before Taking Temodal?

Quick Answer: Do not take Temodal if you are allergic to temozolomide or dacarbazine, or if you have severely reduced blood cell counts (myelosuppression). Tell your doctor about any liver or kidney problems, hepatitis B history, or if you are pregnant or breastfeeding. Regular blood tests are required throughout treatment.

Contraindications

There are specific situations in which Temodal must not be used. Understanding these absolute contraindications is essential before starting treatment.

  • Hypersensitivity: Do not take Temodal if you are allergic to temozolomide or any of the other ingredients in the capsules (including anhydrous lactose, colloidal anhydrous silica, sodium starch glycolate type A, tartaric acid, and stearic acid).
  • Allergy to dacarbazine: If you have had an allergic reaction to dacarbazine (DTIC, another alkylating chemotherapy drug), you should not take Temodal, as the two drugs are chemically related. Signs of allergic reaction include itching, difficulty breathing or wheezing, and swelling of the face, lips, tongue, or throat.
  • Severe myelosuppression: If your white blood cell counts or platelet counts are severely low before starting treatment, Temodal should not be initiated until blood counts recover to acceptable levels. Your doctor will check your blood before prescribing Temodal.

Warnings and Precautions

Before and during treatment with Temodal, inform your doctor if any of the following apply to you:

  • Hepatitis B: If you have ever had or may currently have hepatitis B infection, tell your doctor before starting Temodal. Temozolomide can cause hepatitis B virus reactivation, which in some cases can be fatal. Your doctor will test you for hepatitis B and monitor you for signs of reactivation throughout treatment.
  • Blood count abnormalities: If you have low red blood cells (anemia), low white blood cells, or low platelets before starting treatment, or if you develop these during treatment, your doctor may decide to reduce your dose, delay treatment, discontinue it, or prescribe additional supportive care. Regular blood tests are performed on day 22 (21 days after the first dose) of each cycle, or within 48 hours of that day, and weekly until the absolute neutrophil count (ANC) is above 1.5 × 10&sup9;/L and the platelet count is above 100 × 10&sup9;/L.
  • Risk of secondary cancers: There is a small risk of developing changes to blood cells, including leukemia, as a long-term consequence of temozolomide treatment. This risk must be weighed against the therapeutic benefit.
  • Nausea and vomiting: These are very common side effects of Temodal. Your doctor may prescribe anti-emetic medication (such as ondansetron or granisetron) to be taken before and/or after your Temodal dose. If you vomit after taking your dose, do not take a second dose on the same day.
  • Fever or signs of infection: Contact your doctor immediately if you develop fever or symptoms of infection, as this may indicate that your immune system is compromised due to low white blood cell counts.
  • Age over 70: Older adults may be more susceptible to infections, bruising, and bleeding during temozolomide treatment.
  • Liver or kidney problems: If you have impaired liver or kidney function, your dose may need to be adjusted. Liver function should be tested before each treatment cycle, at the midpoint of each cycle, and at the end of each cycle.

Pregnancy and Breastfeeding

Temodal should not be taken during pregnancy unless your doctor has specifically determined that the potential benefit justifies the potential risk to the fetus. Temozolomide has been shown to be teratogenic (can cause birth defects) and embryotoxic in animal studies. Women of childbearing potential must use effective contraception during treatment and for at least 6 months after the last dose.

Breastfeeding must be discontinued during treatment with Temodal. It is not known whether temozolomide is excreted in human breast milk, but given its mechanism of action, a risk to the breastfed infant cannot be excluded.

Temozolomide can cause permanent infertility in males. Male patients should use effective contraception and should not father a child during treatment or for at least 3 months after the last dose. It is recommended that male patients discuss sperm cryopreservation (freezing) with their doctor before starting treatment.

Driving and Operating Machinery

Temodal may cause fatigue, drowsiness, and dizziness. If you experience any of these side effects, do not drive, operate machinery, or ride a bicycle until you know how the medication affects you. These effects may be compounded by the underlying brain tumor and by concurrent radiotherapy.

Important Information About Ingredients

Temodal capsules contain lactose (a type of sugar). If you have been told by your doctor that you have an intolerance to certain sugars, consult your doctor before taking this medicine. Each capsule also contains less than 1 mmol (23 mg) of sodium, meaning it is essentially sodium-free.

How Does Temodal Interact with Other Drugs?

Quick Answer: Valproic acid may slightly decrease temozolomide clearance and increase the risk of low platelet counts. Other myelosuppressive agents and live vaccines should be avoided during treatment. Temozolomide does not require liver enzyme activation, so CYP450 interactions are minimal.

Temozolomide has a relatively favorable drug interaction profile compared with many other chemotherapy agents. Because it is spontaneously converted to its active form at physiological pH rather than requiring hepatic enzyme activation, it has fewer cytochrome P450-mediated drug interactions than many other anticancer drugs. However, certain interactions are clinically important and should be discussed with your doctor.

Major Interactions

Major Drug Interactions with Temodal
Interacting Drug Effect Clinical Significance
Valproic acid (valproate) Slightly decreased temozolomide clearance; increased risk of thrombocytopenia Monitor platelet counts closely; dose adjustments may be needed
Other myelosuppressive agents Additive bone marrow suppression; increased risk of severe neutropenia, thrombocytopenia, anemia Monitor blood counts more frequently; avoid combination if possible
Live vaccines (e.g., MMR, varicella, BCG) Risk of vaccine-strain infection due to immunosuppression Avoid during treatment and for several months after

Minor Interactions

Other Drug Interactions with Temodal
Interacting Drug Effect Clinical Significance
Dexamethasone (corticosteroid) Commonly co-administered; no significant pharmacokinetic interaction Safe combination; routinely used in brain tumor management
Anti-emetics (ondansetron, granisetron) No significant interaction; used to manage temozolomide-induced nausea Recommended as supportive care
Trimethoprim/sulfamethoxazole Both may contribute to myelosuppression; but PCP prophylaxis is essential Required during concurrent phase; monitor blood counts
Phenytoin / carbamazepine May reduce temozolomide exposure (limited data); commonly used for seizure management in brain tumor patients Use with caution; levetiracetam often preferred as alternative anticonvulsant

Always inform your doctor about all medications you are taking, including herbal supplements, over-the-counter products, and vitamins. While temozolomide itself has limited direct drug interactions, the clinical setting of brain tumor treatment often involves multiple medications (corticosteroids, anticonvulsants, anti-emetics) that may interact with each other. Your oncology team will carefully manage your overall medication regimen to minimize risks.

What Is the Correct Dosage of Temodal?

Quick Answer: The dose of Temodal is based on your body surface area (height and weight). For newly diagnosed GBM, the concurrent phase dose is 75 mg/m² daily for 42 days alongside radiotherapy. The maintenance phase uses 150–200 mg/m² daily for 5 days of each 28-day cycle, for up to 6 cycles. Capsules must be taken on an empty stomach.

Your doctor will determine the correct dose of Temodal based on your body surface area (calculated from your height and weight), your specific diagnosis, your blood test results, and whether you have previously received chemotherapy. You may be prescribed anti-emetic medication to take before and/or after Temodal to prevent nausea and vomiting.

Newly Diagnosed Glioblastoma Multiforme

If you have been newly diagnosed with glioblastoma multiforme, treatment with Temodal is divided into two phases:

Concurrent Phase (with Radiotherapy)

Dose: 75 mg/m² once daily

Duration: 42 days continuously (up to 49 days), taken alongside radiotherapy

Administration: Take capsules on an empty stomach, at least 1 hour before breakfast. Swallow whole with water.

Note: PCP prophylaxis (e.g., trimethoprim/sulfamethoxazole) is required throughout this phase. Your doctor may delay or discontinue Temodal based on your blood counts and tolerability.

After the concurrent phase is completed and radiotherapy has finished, there is a 4-week break to allow your body to recover before starting the monotherapy phase.

Monotherapy Phase (Maintenance)

Cycle 1: 150 mg/m² once daily for 5 days, followed by 23 days without treatment (28-day cycle)

Cycles 2–6: If well tolerated and blood counts are adequate, the dose may be increased to 200 mg/m² once daily for 5 days per 28-day cycle

Duration: Up to 6 cycles total

Note: Blood tests are performed on day 22 of each cycle (or within 48 hours). The dose for the next cycle is determined based on the lowest blood counts recorded.

Recurrent or Progressive Malignant Glioma

Monotherapy for Recurrent Glioma

Patients not previously treated with chemotherapy: 200 mg/m² once daily for the first 5 days of a 28-day cycle

Patients previously treated with chemotherapy: 150 mg/m² once daily for the first 5 days of a 28-day cycle, with potential increase to 200 mg/m² in subsequent cycles if tolerated

Duration: Treatment continues until disease progression or unacceptable toxicity

Children (Older Than 3 Years)

Temodal should not be given to children younger than 3 years of age due to lack of clinical experience. In children older than 3 years with recurrent or progressive malignant glioma, the dosing is the same as for adults: 150–200 mg/m² daily for 5 days of each 28-day cycle, based on prior chemotherapy exposure and tolerability. There is limited clinical data in pediatric patients, and treatment should be supervised by a specialist in pediatric oncology.

Elderly Patients

No specific dose adjustment is required for elderly patients based on age alone. However, patients over 70 years of age may be more susceptible to myelosuppression and infections. Your doctor will monitor your blood counts closely and may adjust the dose or timing of treatment as needed. The landmark clinical trials included patients up to 70 years of age, and more recent studies have confirmed the benefit of temozolomide in elderly patients, particularly those with MGMT-methylated tumors.

Missed Dose

If you forget to take Temodal, take the missed dose as soon as possible on the same day. If a full day has passed, contact your doctor for guidance. Do not take a double dose to make up for a missed dose unless your doctor specifically instructs you to do so. If you vomit after taking your dose, do not take a second dose on the same day.

Overdose

If you accidentally take more capsules than prescribed, contact your doctor, pharmacist, or emergency services immediately. Overdose of temozolomide is likely to cause more severe and prolonged myelosuppression and other side effects. There is no specific antidote; treatment is supportive with close monitoring of blood counts.

How to Take Temodal Capsules

Take your prescribed dose of Temodal once daily, ideally at the same time each day. Take the capsules on an empty stomach — at least one hour before eating breakfast. Swallow the capsules whole with a glass of water. Do not open, crush, or chew the capsules. If a capsule is damaged, avoid getting the powder on your skin, eyes, or nose. If accidental contact occurs, flush the area thoroughly with water.

Depending on your prescribed dose, you may need to take several capsules at once, potentially of different strengths. The capsule cap colors correspond to different strengths to help you identify them:

Temodal Capsule Identification
Strength Cap Color
5 mg Green
20 mg Yellow
100 mg Pink
140 mg Blue
180 mg Orange
250 mg White

Ensure that you know exactly how many capsules of each strength you need to take on your dosing days. Ask your doctor or pharmacist to write this down for you, including the capsule colors. Review your dose with your doctor at the start of each new treatment cycle, as the dose may differ from the previous cycle based on your blood test results.

Safe Handling of Capsules

Temodal capsules contain a cytotoxic (cell-killing) substance. Handle them carefully. If a capsule is broken, avoid contact of the powder with your skin, eyes, or nose. Accidental ingestion by children can be fatal — store capsules out of sight and reach of children, preferably in a locked cabinet. Do not dispose of capsules in household waste; return unused capsules to your pharmacy.

What Are the Side Effects of Temodal?

Quick Answer: The most common side effects of Temodal include nausea, vomiting, headache, fatigue, constipation, loss of appetite, hair loss, and rash. The most clinically important side effect is myelosuppression (reduced blood cell counts), which requires regular monitoring. Seek immediate medical attention for uncontrolled bleeding, seizures, fever, chills, or severe headache.

Like all medicines, Temodal can cause side effects, although not everyone experiences them. The side effect profile may differ depending on whether you are receiving Temodal concurrently with radiotherapy or as monotherapy. Your medical team will monitor you closely and manage side effects as they arise.

Temozolomide treatment can cause a reduction in certain blood cells. This may mean you bruise or bleed more easily, develop anemia (shortage of red blood cells), have fever, and have reduced resistance to infections. The reduced blood cell count is usually temporary. In some cases, it can become prolonged and lead to a very serious form of anemia (aplastic anemia). Your doctor will perform regular blood tests to detect any changes and determine whether specific treatment is required.

Very Common

May affect more than 1 in 10 people

  • Loss of appetite (anorexia)
  • Speech difficulties
  • Headache
  • Nausea and vomiting
  • Diarrhea
  • Constipation
  • Skin rash
  • Hair loss (alopecia)
  • Fatigue and tiredness

Common

May affect up to 1 in 10 people

  • Infections, including oral infections (thrush)
  • Decreased blood cell counts (neutropenia, lymphopenia, thrombocytopenia)
  • Allergic reactions
  • Elevated blood sugar (hyperglycemia)
  • Memory impairment, depression, anxiety, confusion, insomnia
  • Impaired coordination and balance, difficulty concentrating
  • Dizziness, altered sensation, tingling, tremor, taste changes
  • Partial vision loss, abnormal vision, double vision, eye pain
  • Hearing loss, tinnitus (ringing in ears), ear pain
  • Blood clots in lungs or legs, high blood pressure
  • Pneumonia, shortness of breath, bronchitis, cough, sinus infection
  • Stomach or abdominal pain, heartburn, difficulty swallowing
  • Dry skin, itching
  • Muscle damage, muscle weakness, muscle pain
  • Joint pain, back pain
  • Frequent urination, urinary incontinence
  • Fever, flu-like symptoms, feeling unwell, cold or flu
  • Fluid retention, leg swelling
  • Elevated liver enzymes
  • Weight loss or weight gain
  • Radiation injury

Uncommon

May affect up to 1 in 100 people

  • Brain infections (herpes meningoencephalitis), which can be fatal
  • Wound infections
  • New or reactivated cytomegalovirus (CMV) infections
  • Reactivated hepatitis B virus infections
  • Secondary cancers including leukemia
  • Decreased blood cell counts (pancytopenia, anemia, leukopenia)
  • Petechiae (red pinpoint spots under the skin)
  • Diabetes insipidus (increased urination and thirst), low potassium levels
  • Mood swings, hallucinations
  • Partial paralysis, changes in sense of smell
  • Hearing impairment, middle ear infections
  • Palpitations, hot flashes
  • Bloating, difficulty controlling bowel movements, hemorrhoids, dry mouth
  • Liver inflammation and liver damage (including fatal liver failure), cholestasis, elevated bilirubin
  • Blisters on body or in mouth, skin peeling, skin reactions, painful skin redness, severe rash with skin swelling (palms and soles)
  • Increased sun sensitivity, hives, increased sweating, skin color changes
  • Difficulty urinating
  • Vaginal bleeding, vaginal irritation, absent or heavy periods, breast pain, sexual impotence
  • Tremors, facial swelling, tongue discoloration, thirst, dental problems
  • Dry eyes

How Should You Store Temodal?

Quick Answer: Store Temodal capsules below 30°C (86°F), out of sight and reach of children (preferably in a locked cabinet). Check the expiration date before use and return any unused or expired capsules to your pharmacy for safe disposal.

Proper storage of Temodal is essential both for maintaining the drug's effectiveness and for safety, particularly in households with children. Accidental ingestion by a child can be fatal.

  • Temperature: Store at or below 30°C (86°F). Do not freeze.
  • Child safety: Keep out of sight and reach of children, preferably in a locked cabinet. Accidental ingestion can be fatal for children.
  • Packaging: Each capsule is individually sealed in a dose sachet within its carton. Keep capsules in their original packaging until use.
  • Expiration: Do not use Temodal after the expiration date printed on the dose sachet and carton. The expiration date refers to the last day of that month.
  • Inspection: If you notice any change in the appearance of the capsules, inform your pharmacist.
  • Disposal: Do not dispose of capsules in household waste or flush them down the drain. Return unused or expired capsules to your pharmacy for safe disposal. These measures help protect the environment.

What Does Temodal Contain?

Quick Answer: The active ingredient is temozolomide, available in 5 mg, 20 mg, 100 mg, 140 mg, 180 mg, and 250 mg hard capsules. Inactive ingredients include anhydrous lactose, colloidal anhydrous silica, sodium starch glycolate type A, tartaric acid, and stearic acid.

Each Temodal capsule contains temozolomide as the active substance. The capsules are available in six different strengths to allow flexible dosing based on body surface area:

  • Temodal 5 mg: Green cap with white body, marked "TEMODAL" and "5 mg"
  • Temodal 20 mg: Yellow cap with white body, marked "TEMODAL" and "20 mg"
  • Temodal 100 mg: Pink cap with white body, marked "TEMODAL" and "100 mg"
  • Temodal 140 mg: Blue cap with white body, marked "TEMODAL" and "140 mg"
  • Temodal 180 mg: Orange cap with white body, marked "TEMODAL" and "180 mg"
  • Temodal 250 mg: White cap with white body, marked "TEMODAL" and "250 mg"

The other ingredients (excipients) in the capsule contents are: anhydrous lactose, colloidal anhydrous silica, sodium starch glycolate type A, tartaric acid, and stearic acid. The capsule shells are made of gelatin, titanium dioxide (E 171), and sodium lauryl sulfate, with different iron oxide colorants depending on the strength. The printing ink contains shellack, propylene glycol (E 1520), purified water, ammonium hydroxide, potassium hydroxide, and black iron oxide (E 172).

Temodal capsules are packaged in cartons containing 5 or 20 capsules, each individually sealed in a dose sachet. Not all pack sizes may be marketed in all countries. Generic versions of temozolomide are available under various brand names including Temozolomid STADA, Temozolomide Accord, Temozolomide SUN, and Temomedac.

Frequently Asked Questions About Temodal

Temodal (temozolomide) is used to treat specific types of brain tumors. It is the standard chemotherapy for newly diagnosed glioblastoma multiforme (GBM) in adults, used first alongside radiotherapy and then as maintenance therapy. It is also used for recurrent or progressive malignant glioma (including GBM and anaplastic astrocytoma) in children older than 3 years and adults.

Temozolomide is a prodrug that spontaneously converts to an active alkylating compound (MTIC) at the body's normal pH. MTIC adds methyl groups to DNA, primarily at the O6 position of guanine, causing DNA mismatches during replication. This triggers failed DNA repair attempts, strand breaks, and ultimately programmed cell death (apoptosis). Its key advantage is its ability to cross the blood-brain barrier, reaching therapeutic concentrations in the brain.

No, Temodal should be taken on an empty stomach, at least one hour before eating breakfast. Food can reduce the rate of drug absorption. The capsules should be swallowed whole with a glass of water — do not open, crush, or chew them. Take them at the same time each day for consistency.

MGMT (O6-methylguanine-DNA methyltransferase) is a DNA repair enzyme that can reverse the damage temozolomide causes to cancer cell DNA. When the MGMT gene promoter is methylated (silenced), tumors produce less of this repair enzyme and are more sensitive to temozolomide. Patients with MGMT-methylated tumors generally have better response rates and improved survival. Your doctor may test your tumor for this biomarker to help guide treatment decisions.

Yes, hair loss (alopecia) is listed as a very common side effect of Temodal, occurring in more than 1 in 10 patients. However, the hair loss associated with temozolomide is generally less severe than that seen with many other chemotherapy agents. Many patients experience thinning rather than complete hair loss, and hair typically regrows after treatment is completed. Concurrent radiotherapy to the head may also contribute to hair loss in the treatment field.

For newly diagnosed GBM, the total treatment duration is typically 10–12 months: 6 weeks of daily temozolomide during the concurrent phase with radiotherapy, followed by a 4-week break, and then up to 6 cycles of 28 days each during the maintenance phase. For recurrent glioma, treatment continues until disease progression or unacceptable side effects. Your doctor will regularly evaluate whether continuing treatment is appropriate.

References

  1. Stupp R, Mason WP, van den Bent MJ, et al. Radiotherapy plus concomitant and adjuvant temozolomide for glioblastoma. New England Journal of Medicine. 2005;352(10):987-996. doi:10.1056/NEJMoa043330
  2. Stupp R, Hegi ME, Mason WP, et al. Effects of radiotherapy with concomitant and adjuvant temozolomide versus radiotherapy alone on survival in glioblastoma in a randomised phase III study: 5-year analysis of the EORTC-NCIC trial. Lancet Oncology. 2009;10(5):459-466.
  3. European Medicines Agency (EMA). Temodal — Summary of Product Characteristics. Last updated 2025. Available at: https://www.ema.europa.eu
  4. U.S. Food and Drug Administration (FDA). Temodar (temozolomide) — Prescribing Information. Last updated 2024.
  5. National Comprehensive Cancer Network (NCCN). Clinical Practice Guidelines in Oncology: Central Nervous System Cancers. Version 2.2025.
  6. Weller M, van den Bent M, Preusser M, et al. EANO guidelines on the diagnosis and treatment of diffuse gliomas of adulthood. Nature Reviews Clinical Oncology. 2024;21:29-49.
  7. Hegi ME, Diserens AC, Gorlia T, et al. MGMT gene silencing and benefit from temozolomide in glioblastoma. New England Journal of Medicine. 2005;352(10):997-1003.
  8. World Health Organization (WHO). WHO Classification of Tumours: Central Nervous System Tumours. 5th edition. 2021.
  9. Perry JR, Laperriere N, O'Callaghan CJ, et al. Short-Course Radiation plus Temozolomide in Elderly Patients with Glioblastoma. New England Journal of Medicine. 2017;376(11):1027-1037.

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