Temozolomide

Say it: tem-oh-ZOH-loh-mide · Brand names: Temodar

Temozolomide is a chemotherapy pill that damages the DNA in brain tumor cells so they cannot grow.

What it is

Temozolomide changes into its active form in the body. It adds small chemical pieces to the DNA in cells, which damages it. Tumor cells cannot copy themselves and die. It can reach the brain well.

Often used for

• glioblastoma, a type of brain tumor
• anaplastic astrocytoma, a type of brain tumor

How you get it

Temozolomide is usually a capsule you take at home, once a day. It is often taken every day during radiation, then later for 5 days in a row every 4 weeks. It can also be given through a vein (IV). Your schedule may be different.

Common side effects and what helps

• Nausea and vomiting. Take your anti-nausea medicine before your dose as your team tells you.
• Feeling tired. Rest and short walks can help.
• Constipation. Drink fluids, eat fiber, and ask your team about a stool softener.
• Headache. Tell your team, and ask what pain medicine is safe.
• Poor appetite. Try small meals and snacks.
• Hair thinning. It often grows back.
• Low blood counts, which raise your risk of infection and bleeding. Wash your hands often.

Call your care team right away if you have

• A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, or chills
• Bleeding or bruising that will not stop, black or bloody stools, or blood in your urine
• A new cough, shortness of breath, or trouble breathing
• Vomiting so much you cannot keep your pills or fluids down
• Yellow skin or eyes, or dark urine
• A new seizure or a sudden change in thinking or strength

Before you start, tell your team

• If you are pregnant, may become pregnant, or are breastfeeding
• If you have liver or kidney problems
• If you have had a reaction to dacarbazine
• All the medicines, vitamins, and herbal products you take

Good to know

• You will have blood tests often to check your blood counts and liver.
• During radiation, your team may give you a medicine to prevent a lung infection called pneumonia (PCP).
• It can harm an unborn baby. Women and men should use birth control during treatment and for a time after.
• Rarely, it can cause a new blood cancer years later.

At home

• Swallow the capsules whole with water. Do not open, chew, or crush them.
• Take it the same way each day. Many people take it on an empty stomach or at bedtime to reduce nausea. Follow your team's plan.
• If a capsule breaks, do not touch the powder. Clean it up with gloves and wash your hands.
• If you miss a dose or vomit after a dose, ask your team what to do. Do not take an extra dose on your own.
• Store at room temperature in the original bottle, away from children and pets.

Questions to ask

• Which days do I take this medicine?
• Should I take it with food or on an empty stomach?
• Do I need medicine to prevent infection during radiation?
• How often will I need blood tests?

Side effect guides

• Fatigue (tiredness)
• Nausea and vomiting
• Constipation
• Appetite loss and weight loss
• Hair loss
• Low white blood cells and infection risk
• Low platelets and bleeding
• Pain

Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.