Temodar
Meaning of Temodar: The brand name for temozolomide, one of the few chemotherapy drugs that reaches brain tissue in useful amounts.
Definition of Temodar
Temodar is a brand name for temozolomide, a chemotherapy drug taken by mouth for certain brain tumors. It attaches a small chemical group to DNA inside dividing cells, damaging the strand so the cell cannot copy itself and dies instead. Unlike most chemotherapy, it passes into brain tissue readily, and it is swallowed as capsules rather than dripped into a vein.
What is it used for?
The main use is glioblastoma, the most common aggressive brain tumor in adults. It is given during radiation treatment and then continued alone in monthly cycles. It is also used for anaplastic astrocytoma that has come back or has stopped responding to earlier treatment. The same drug under its generic name, temozolomide, is used in some other tumors, including certain neuroendocrine and pituitary tumors that resist other options.
How does it work?
Temozolomide is an alkylating agent. After it is swallowed it converts by itself into an active form, without needing the liver to switch it on. That active form parks a methyl group on DNA. The damage confuses the machinery that copies DNA, and the cell triggers its own death. Cells that divide fastest are hit hardest, which is why tumor cells suffer more than most healthy tissue, and why bone marrow and the gut lining are the tissues most often affected as well.
Why does MGMT matter?
Cells carry a repair enzyme called MGMT that plucks the added methyl group straight back off the DNA. A tumor rich in that enzyme repairs the damage and shrugs the drug off. In many glioblastomas the MGMT gene has been chemically silenced, so little enzyme is made and the drug works far better. Laboratories test tumor tissue for that silencing, and the result helps predict how much benefit to expect.
What are the main effects on the body?
| Effect | Why it happens |
|---|---|
| Low blood counts | Bone marrow cells divide constantly and are damaged too |
| Nausea and vomiting | A direct effect of the drug, usually managed with anti-sickness medicine |
| Tiredness | Common, and hard to separate from the effects of radiation |
| Constipation | Partly the drug, partly the anti-sickness medicine given with it |
Also known as
Used in a sentence
Temodar was continued in monthly cycles after the six weeks of combined radiation and chemotherapy ended.
Good to know
Temodar and temozolomide are the same medicine under two names, and the MGMT status of the tumor is the strongest available guide to how well it is likely to respond.