Temozolomide And Its Side-Effects In Cancer Patients

Temozolomide is an anticancer drug that is active against skin cancers, most specifically melanoma. It is usually used to treat this cancer when it has become metastatic (spread to other parts of the body), especially if it has spread to the brain.

Uses of Temozolomide:

  • It is used to treat brain cancers such as astrocytomas.
  • The drug can be used as a first-time treatment or for a recurrence of cancer.
  • Recurrent or progressive malignant gliomas may be treated with Temozolomide when treating children.
  • It is used to treat skin cancers like melanomas.

Drug Administration:

The drug comes in two forms. The most often used is the capsule. It is usually taken at bedtime once a day. You doctor will give you your treatment calendar. A Full dose might contain more than one type and color of the capsule to make up your full dose and, therefore, will be contained in more than a single prescription bottle.

Be sure you understand how to take the drug. Do not touch anything, including your skin, until you have washed your hands after handling your medication. Accidentally getting the powder of this drug into your eyes or nose can cause serious problems.

The other form of the drug is injectable that can be slowly infused when needed.  

Purpose of Temozolomide:

An antineoplastic drug or anti-cancer medication has the primary action of inhibiting and eradicating cancer cells. Temozolomide is used for refractory anaplastic astrocytoma in adults (astrocytoma is the primary tumor of the brain.)

Temozolomide is used with radiotherapy to treat adults with newly diagnosed glioblastoma multiforme or cystic tumor of the cerebrum and then as maintenance treatment.

How does Temozolomide work?

Temozolomide is an alkylating agent. It places a methyl group onto part of the DNA. It makes the DNA function incorrectly, and it can no longer divide. The cell dies. The drug will affect rapidly dividing cells such as cancer cells the most. Unfortunately, it will also affect rapidly dividing normal cells such as:

  • Blood cells
  • Skin and hair cells
  • The cells that line your digestive tract.

It is how you experience side effects.

Side effects of Temozolomide and how to overcome them:

If you vomit immediately after taking the medication, you need to contact your doctor immediately. Do not take more Temozolomide unless instructed to do so. You may need to take specific anti-nausea/vomiting drugs prior to taking the Temozolomide.  

  • Nausea: It is not unusual to have problems with nausea while on this drug. Talk with your physician about taking an anti-nausea drug. Taking the drug right before bedtime may help with nausea, you won’t be awake to experience it. It seems that taking the capsules on an empty stomach will help avoid some of the problems with nausea.
  • Constipation: Along with your problems of nausea and possibly vomiting you may have constipation. Plan on a good diet and possibly stool softeners to help keep things moving. Be sure to discuss it with your doctors.
  • A headache and fatigue occur in over 30% of patients on Temozolomide.  You may not use NSAIDs or aspirin, but acetaminophen in low doses may be used to treat a headache. Other drugs you can use will be available from your doctor.  
  • Drop in blood counts: About 10-30% of patients on Temozolomide will have a drop in their blood counts. It can affect all three main types of cells in the blood:
    • White blood cells
    • Red blood cells
    • Platelets.

The lowest counts will usually come about 7 to 10 days after starting the drug and recover 22 to 28 days after finishing the drug. Your doctor may check your blood count intermittently throughout treatment.    

  • The risk of infection: If your (WBC) white blood cell count is low you will be at a higher risk of infection. If you develop following symptoms of an infection you need to contact your doctor immediately:
  • Fever
  • Chills
  • Sore throat
  • Cough
  • Sinus congestion
  • Urinary frequency
  • Pain with urination

Do not assume that your body can fight even a minor infection.

  • Shingles: Your risk of developing shingles (viral infection producing a rash) is elevated while on Temozolomide, especially severe case. Beware of exposure to chickenpox.
  • Bleeding: If your platelet count is low you’ll be slightly more likely to develop bleeding. It could be digestive or urinary tract bleeding that could present as:
  • Black tarry stools
  • Blood in your urine
  • Nose bleeds
  • Coughing up blood.  
  • Anemia: While your red blood cell count is low you will be anemic. It can lead to:
  • Dizziness
  • Sweating or chills
  • Paleness
  • Extreme tiredness
  • Shortness of breath
  • Chest pain  

Be careful about your activities if you are extremely tired or dizzy so that you would not put yourself at risk. You may need to avoid driving or use of heavy machinery as well as overall limiting what you do so as not to tire yourself out.

  • Hair loss: Up to 60% of people on Temozolomide will develop temporary hair loss. Remember that it will return after you finish your treatment.
  • Mouth sores: Another place that could be affected by the Temozolomide is the inside of your mouth. You may notice that it is sore and you could even develop sores. Be sure that you make your health care provider aware if this is happening.  

Delayed onset side effects:

Some people will notice delayed onset (late onset) side effects. These can include:

  • Fluid retention with swelling and edema.
  • You could also notice diarrhea or weakness.  
  • Sometimes skin problems such as a rash or itching will start to occur.
  • Central neurotoxicity with problems of:
  • dizziness
  • Poor balance
  • One side of the body weakness
  • Seizures
  • Excessive sleepiness
  • You may notice vision changes such as blurriness.  

Most people, including you, will not experience all of the side effects listed above. Some side effects will occur only at specific times and will be of limited duration. Any problems you experience are almost always reversible and will go away after treatment is complete, and your body will heal.

There is never a relationship between the severity of side effects and how well the medication is working, so if you are lucky and develop very few or only very, mild side effects don’t feel as though the drug can’t be working. Higher doses of Temozolomide may cause more side effects.  

Drug interactions:

Tell your doctor if you’re on the following medicines:

  • Carbamazepine
  • Co-trimoxazole (Bactrim or Septra)
  • Phenytoin
  • Dexamethasone
  • Methylprednisolone
  • Prednisone, or valproic acid.  

You also must let your doctor know if you are taking warfarin, ticlopidine, or clopidogrel as these can cause increased problems while on Temozolomide.  

Avoid taking non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen, naproxen and others.

It is not advised to take vitamin E supplements, but discuss about this issue with your doctor.

Precautions:

  • Temozolomide can affect sperm production, but you cannot assume you are sterile. You do not want to become pregnant (man or woman) while on this drug so be sure to be using a very reliable form of birth control. If you do conceive you must notify your doctor as the unborn child can be affected and harmed. Also, women should avoid breastfeeding while on this drug.
  • Your doctor needs to know about all of your medical problems, but two of the more important ones are kidney or liver disease. You will need to be carefully monitored.

Self-care tips:

  • Stay aside from people suffering from a cold or flu, since you may be more likely to pick up an infection. Avoid any immunization or vaccination while receiving Temozolomide. Be especially careful around anyone who has received a live-attenuated vaccination as you could catch the disease from their shedding of the attenuated organism.  
  • Also be careful around a child with chickenpox. You want to keep your elevated risk of developing shingles in mind and could bring on an episode after exposure to chickenpox.
  • You could bruise or bleed easier. Stay away from contact sports. Consider using a soft bristle toothbrush. Be careful when shaving.
  • Drink 2 to 3 quarter of fluids daily unless otherwise instructed by your health care providers. The fluid will help avoid severe constipation.
  • Avoid alcoholic beverages while receiving Temozolomide. Both alcohol and caffeine act as diuretics, which can pull fluid from your bowel (where you need it right now).
  • Washing your hands often, especially after returning from outside of your home, is one of the best ways to ward off infection. Also, keep in mind to wash your hands immediately after handling your medication..
  • Take care of your mouth with good oral hygiene. If your mouth becomes too sore to brush your teeth with a soft bristle brush find out about using oral rinses multiple times a day from your care providers or dentist. Everything you do will help keep the development of mouth sores and infection to a minimum.
  • Do your best to keep up good nutrition. Whenever possible try to eat a high fiber diet along with juicy foods (to increase your overall fluid intake). If you lose your appetite or have difficulties with nausea during treatment, eat what interests you the most or tastes the best.
  • Try chewing gum or sucking on candy as it may help. You may find that focusing on drinking nutritious drinks will be easier than worrying about full meals.
  • Try to avoid needing to cook and being around strong food smells when you are not feeling well. They will only make things worse.
  • Get rest and try reducing stress. Practice how to meditate or do yoga, pilates, or tai chi as ways to relax. Some people find that light exercise during the day helps them to relax and sleep better at night.

Conclusion:

Temozolomide has an antineoplastic drug, or anti-cancer medication has the primary action of inhibiting and eradicating cancer cells. The most common side effects seen are fatigue, asthenia (exhaustion or loss of strength), constipation, diarrhea, abnormal coordination, nausea, vomiting, amnesia (loss of memory), convulsions, dizziness, hemiparesis (muscular weakness of one half of the body), insomnia (inability to sleep), fever and viral infection, weight increase, and myalgia (muscle pain sometimes accompanied with body weakness)

 

References:

  1. Temozolomide wiki
  2. Temozolomide for high grade glioma
  3. What is temozolomide
  4. Temozar- Temozolomide
  5. Uses of Temozolomide