Temozolomide

Temozolomide is a drug used to treat certain types of brain cancer in patients, such as anaplastic astrocytoma and glioblastoma multiforme.

Overview

Temozolomide belongs to a family of cancer medicines called antineoplastics. These drugs work by interfering with the production of cancer cells, resulting in them being destroyed by the body. It is usually prescribed to patients to shrink tumors that have just been discovered, or those that have just returned.

There are various side effects that those using temozolomide should be aware of, any are commonly experienced by those taking the medication. This is because having a temozolomide injection may also interfere with the production of normal body cells. Some of these side effects can be serious, so patients on a course of these injections must be closely monitored at all times to ensure that these symptoms do not become unmanageable.

Because of the serious nature of the side effects that may be presented by temozolomide, it is especially important that a patient undergoes a full health assessment prior to administration of the injection - and that the doctor is fully aware of the patient's health history and other medications taken.

The drug is supplied in powder form, which can create an injectable solution. It is also available under the brand name Temodar in the United States.

Before administering temozolomide, the risks of taking such medication versus those health benefits to the patient must be weighed up. Temozolomide can be an effective and potentially life-saving treatment for reducing brain cancers but can cause the patient considerable side effects.

Conditions treated

  • Brain cancers – glioblastoma multiforme; anaplastic astrocytoma

Type of medicine

  • Powder – through intravenous route

Side effects

Temozolomide comes with the risk of various side effects for the patient. It should be used under close supervision. The drug can cause serious side effects in some patients. You should immediately contact your doctor if you experience any of the following symptoms outlined below.

The most serious side effect is that of decreased blood cells. As temozolomide affects the growth of bone marrow cells and white blood cells, you may be more prone to infections when taking this medication. Your blood will be monitored by your doctor throughout your treatment so that this side effect can be caught early. If it is detected that you are producing fewer neutrolphils (the white blood cells needed to fight infection) you will be closely monitored, and you must take all possible precautions not to put yourself at risk of infection. Decreased numbers of neutrophils can lead to serious infections; your body’s inability to fight those infections could lead to death.

Temozolomide can also lead to the reduction of platelets, which are the blood cells that are needed to enable normal blood clotting. You should immediately tell your doctor if you experience any unusual bleeding or bruising, as these are signs of decreased production of platelets.

Your doctor may decide to change your dosage of temozolomide if you are experiencing a rapid decline in white blood cells. These side effects are more common in those over the age of 70. Other serious side effects include:

  • Pneumocystis Pneumonia – this is an infection that affects those typically when they have weak immune systems, which is caused by a lack of white blood cells. Signs of PCP include fever, chills, shortness of breath or a dry cough
  • Convulsions – which can be life-threatening for those on temozolomide
  • Secondary cancers – those who are taking temozolomide are vulnerable to the development of secondary cancers such as leukemia
  • Blood problems – such as myelodysplastic syndrome
  • Liver problems, which can result in death in very rare cases

There are also several more common, and less severe, side effects that patients taking temozolomide can experience. These include:

  • Nausea and vomiting
  • Extreme tiredness
  • Headache or migraine
  • Hair loss
  • Poor appetite
  • Skin conditions, such as rashes and spots
  • Diarrhea
  • Weakness
  • Dizziness
  • Fever
  • Constipation
  • Viral infections
  • Lack of coordination or confusion
  • Insomnia or irregular sleep
  • Paralysis in part of the body
  • Swelling, redness, soreness, itching, hotness or irritation around the area of injection
  • Memory loss
  • Bruising of the skin

Dosage

The dosage set for patients depends on their body surface area (BSA). [ref 1]

The dose of temozolomide via injection is the same as that set for temozolomide in the oral capsule form, over a 90 minute period. The initial dose is 150 mg/m2 once per day for five consecutive days per 28 day treatment cycle.

This dose may be increased in persistent cases, and if the patient is responding well to the medication without signs of any severe side effects. The usual increased amount is 200 mg/m2 per day for five consecutive days per 28-day treatment cycle.

During the 28-day treatment course, a blood count will be collected on day 22, or within 48 hours of this time. Then the blood count will take place weekly until the patient’s ANC level is above 1.5 x 109L, and the platelet count is greater than 100 x 109L. The next cycle of temozolomide will not be prescribed until the body has reached these levels of producing blood cells. If this level of blood cell production falls below 1.0 x 109/L, or the count of platelet blood cells falls below 50 x 109L, the next treatment cycle will be cut by 50 mg/m2. This is so that the patient’s body produces enough blood cells to fight infections.

The temozolomide treatment cycles should then be continued for the patient, up until the point where either the patient experiences unbearable side effects, or it is determined that the disease has progressed. If either of these incidences occur, your doctor may offer an alternative treatment, or may alter your dosage.

Major drug interactions

There are 184 drugs that have been found to interact with temozolomide, meaning that they may alter the effectiveness of the drug. It may also be dangerous to take temozolomide while taking drugs that have been found to have an interaction. Severity of these interactions varies, and those with minor or moderate interactions may still be able to be taken with temozolomide. However, your doctor may alter your prescription based on this.

There are 34 drugs that have been found to have a major interaction with temozolomide (88 generic and brand name drugs). You should be particularly aware to let your doctor know if you are taking any of these medications. If you are taking one or more of these, your doctor may be able to provide an alternative to temozolomide, or you may need to stop taking your other prescription. These drugs are:

  • ACAM2000 (smallpox vaccine)
  • adalimumab
  • Amjevita (adalimumab)
  • Arava (leflunomide)
  • Attenuvax (measles virus vaccine)
  • Aubagio (teriflunomide)
  • bcg
  • Biavax II (mumps virus vaccine, rubella virus vaccine)
  • certolizumab
  • Cimzia (certolizumab)
  • Clopine (clozapine)
  • clozapine
  • Clozapine Synthon (clozapine)
  • Clozaril (clozapine)
  • Cyltezo (adalimumab)
  • deferiprone
  • Denzapine (clozapine)
  • Dryvax (smallpox vaccine)
  • Enbrel (etanercept)
  • Erelzi (etanercept)
  • etanercept
  • FazaClo (clozapine)
  • Ferriprox (deferiprone)
  • fingolimod
  • FluMist (influenza virus vaccine, live, trivalent)
  • FluMist Quadrivalent (influenza virus vaccine, live, trivalent)
  • Gilenya (fingolimod)
  • golimumab
  • Humira (adalimumab)
  • Imlygic (talimogene laherparepvec)
  • Inflectra (infliximab)
  • infliximab
  • influenza virus vaccine, h1n1, live
  • influenza virus vaccine, live, trivalent
  • Juxtapid (lomitapide)
  • Kynamro (mipomersen)
  • leflunomide
  • lomitapide
  • M-M-R II (measles virus vaccine, mumps virus vaccine, rubella virus vaccine)
  • M-R-Vax II (measles virus vaccine, rubella virus vaccine)
  • measles virus vaccine
  • measles virus vaccine, mumps virus vaccine, rubella virus vaccine
  • measles virus vaccine, mumps virus vaccine, rubella virus vaccine, varicella virus vaccine
  • measles virus vaccine, rubella virus vaccine
  • Meruvax II (rubella virus vaccine)
  • mipomersen
  • mumps virus vaccine
  • mumps virus vaccine, rubella virus vaccine
  • Mumpsvax (mumps virus vaccine)
  • natalizumab
  • Orimune (poliovirus vaccine, live, trivalent)
  • poliovirus vaccine, live, trivalent
  • ProQuad (measles virus vaccine, mumps virus vaccine, rubella virus vaccine, varicella virus vaccine)
  • Quadramet (samarium sm 153 lexidronam)
  • Remicade (infliximab)
  • Renflexis (infliximab)
  • Rotarix (rotavirus vaccine)
  • RotaShield (rotavirus vaccine)
  • RotaTeq (rotavirus vaccine)
  • rotavirus vaccine
  • rubella virus vaccine
  • samarium sm 153 lexidronam
  • Simponi (golimumab)
  • Simponi Aria (golimumab)
  • smallpox vaccine
  • Stamaril (yellow fever vaccine)
  • talimogene laherparepvec
  • teriflunomide
  • thalidomide
  • Thalomid (thalidomide)
  • TheraCys (bcg)
  • Tice BCG (bcg)
  • Tice BCG Vaccine (bcg)
  • tofacitinib
  • typhoid vaccine, live
  • Tysabri (natalizumab)
  • varicella virus vaccine
  • Varivax (varicella virus vaccine)
  • Versacloz (clozapine)
  • Vivotif Berna (typhoid vaccine, live)
  • Vivotif Berna Vaccine (typhoid vaccine, live)
  • Xeljanz (tofacitinib)
  • Xeljanz XR (tofacitinib)
  • yellow fever vaccine
  • YF-Vax (yellow fever vaccine)
  • Zaponex (clozapine)
  • Zostavax (zoster vaccine live)
  • zoster vaccine live

There are 184 drugs that have been found to have an interaction with telozolomide, including others that have a moderate or minor interaction with temozolomide. [ref 2]

Warnings

There are various factors you should consider before taking an injection of temozolomide. The preparation stage for taking temozolomide is of high importance, due to the severe side effects.

Allergies

Always tell your doctor if you have any allergies – to temozolomide or any similar medications. You will not be able to take temozolomide if you are allergic to it, so your doctor may be able to prescribe an alternative treatment. Also tell your doctor if you are allergic to any food, animals, preservatives, medicinal ingredients or anything else.

Pregnancy

Those taking Temozolomide should avoid becoming pregnant while taking the treatment. The drug has been found to cause harm to unborn babies.

Other diseases

There are various other conditions that could impact on the effectiveness of your temozolomide. Always tell your doctor before your treatment starts if you suffer from any other illnesses or conditions. This may alter your receptiveness to temozolomide and may change your doctor’s prescription. The following conditions are found to have an interaction with temozolomide. Taking temozolomide while experiencing any of these conditions can make these conditions worse, or can impact on the effectiveness of temozolomide:

  • Urticaria
  • Hepatic Impairment
  • Myelosuppression
  • Renal Impairment
  • Bone marrow issues, such as leukemia, anemia, pancytopenia, myelodysplastic syndrome or thrombocytopenia
  • Kidney infections or diseases
  • Liver infections or diseases
  • Infections of any kind

Storage

Temozolomide is administered by a doctor. The substance should be stored by a qualified physician or doctor in temperatures that do not exceed 30 degrees centigrade and do not fall below 15 degrees centigrade. The drug must be kept away from direct light and heat sources, such as sunlight, radiators and artificial light. Do not refrigerate this medication.

The medicine should be kept out of the reach and sight of children at all times, and should only be used by the person for whom it is prescribed.

Summary

Temozolomide is an effective and tough treatment for life-threatening brain cancers and is used to treat both new and returning tumors. It has been found in major clinical studies to prevent the disease progressing and offer patients an extended life expectancy. It is a chemotherapy drug that, when taken in addition to radiation therapy, can significantly increase the patient’s prognosis and manage brain cancers for longer. Survival rates among those that have taken temozolomide have been found to improve.

Temozolomide has also been found to offer a moderate increase in life expectancy among older patients experiencing the most aggressive form of brain cancer. Typically, those over 70 have only been recommended treatments of radiotherapy to treat their conditions. However, when radiotherapy is combined with temozolomide, these patients can expect to see their prognosis increased by several months. [ref 3]

Temozolomide is a drug that can destroy cells that grow fast, particularly cancer cells. However, it can also destroy other cells that are essential to human health. Therefore, patients that are taking this medication should be monitored daily to ensure that they are not reaching dangerously low levels of white blood cells and bone marrow cells.

Overall, although the side effects and the risks associated with taking temozolomide via injection are significant, the health benefits and prolonged life expectancy can often outweigh this. If patients respond well to the medication, they can go on using it for longer-term periods, with it often acting as a vital lifeline for those whose diseases would have otherwise progressed.

Overall, there is much research into the effectiveness of Temozolomide for sufferers of certain forms of brain cancer. Patients who are considering this treatment should always be made aware of the risks involved in the treatment, and should also always be upfront with their doctors about any other medications they are taking, and any other conditions they are suffering from or have suffered from. As long as the doctor is fully aware of medical history and monitors the patient closely, the drug can be used as a mid- to long-term treatment for brain cancer in people of all ages.

Resources
Last Reviewed:
December 23, 2017
Last Updated:
February 11, 2018