Temsirolimus is used to treat kidney cancer or mantle cell lymphoma.


Temsirolimus is a type of treatment called an mTOR inhibitor—also known as a cancer growth inhibitor. mTOR is a protein inside cells that makes them divide and grow, and is often overly active in cancer cells.

Temsirolimus acts by blocking the mTOR protein; this can help stop cancer from growing or slow its growth.

It can also stop cancer cells from making new blood vessels. This reduces the supply of oxygen and nutrients, making the tumor shrink or stop growing.


Temsirolimus can be used to treat people with some types of kidney cancer that has spread (advanced cancer). It can also be used to treat people with mantle cell lymphoma that has returned following chemotherapy or has not responded to chemotherapy.

Talk to your doctor to see if they recommend temsirolimus for your type of cancer.


Temsirolimus is given as a drip into a vein (called intravenous infusion). Each infusion takes between 30 and 60 minutes. The treatment is usually given once a week. The number of doses you receive will depend on how well it is working and the impact the side effects have on you. Talk to your doctor or specialist nurse about how many treatments you will be having.


Each person reacts differently to cancer treatment. Some people have very few side effects, while others may develop more. The side effects described here will not affect everyone who is treated with the drug.

We outline the most commonly side effects, though we have left out the rarer ones. If you notice you develop any side effects that are not listed here, talk to your doctor or specialist nurse.

The side effects of temsirolimus are normally mild, and some can be relieved with drugs. These side effects fall into two groups:

  • Infusion-related reactions, which can occur during the infusion or over a maximum of about 24 hours thereafter.
  • Other side effects that can happen days or even weeks later.

Infusion-related reactions

These are uncommon and affect fewer than 5 out of every 100 given the infusion. If reactions do happen, they are normally mild, though in rare cases they can be severe. You can take drugs before the infusion to reduce the likelihood of having a reaction. If you have a reaction, the drip is usually lowered or stopped until you feel better. Future infusions will be given at a slower pace.

You will be closely monitored during your treatment, though you should tell your nurse or doctor if you feel unwell or have any of the following symptoms:

  • flu-like symptoms, such as feeling flushed or having a fever, shivering, or nausea
  • red, warm, and itchy bumps on the skin (such as urticaria)
  • a feeling of swelling in the lips, tongue, or throat
  • breathlessness, wheezing, cough, or sudden difficulty breathing
  • back or stomach pain
  • chest pain or pressure in your chest.

Rarely, a reaction related to the infusion can happen a couple of hours after the treatment. If you develop these symptoms or feel unwell after you get home, get in touch with your hospital immediately for advice.



Temsirolimus may lower the number of white blood cells in your blood. This will make you more susceptible to infection. When your white blood cells are low it is called neutropenia

Contact your doctor or your hospital immediately if:

your temperature rises above 38 ° C

you suddenly feel unwell, even if your temperature is normal.

you have symptoms of infection, which may include sore throat, coughing, diarrhea, or the need to urinate frequently.

The number of white blood cells normally increases gradually, returning to normal before your next chemotherapy treatment. You will have a blood test done before your next chemotherapy. If your white blood cells are still low, your doctor may postpone the treatment for a short period of time.


Temsirolimus can reduce the number of red blood cells, which transport oxygen throughout the body. A low red blood cell count is called anemia. This may make you feel tired and short of breath. Tell your doctor or nurse if you have these symptoms. If the number of red blood cells you have is too low, you may need a blood transfusion.


Temsirolimus may lower the number of platelets in your blood. Platelets are cells that help the blood to clot. Tell your doctor if you have any unexplained bleeding or bruising. This includes nosebleeds, bleeding gums, blood spots, or skin eruptions (rashes). If you have a low platelet count, you may have a drip to give you additional platelets (platelet transfusion).


Tiredness is a common side effect, especially toward the end of treatment and for a few weeks after the treatment has finished. It is important that you try to pace yourself and rest as much as you need to. Try to balance this with light exercise, such as taking short walks. If you feel drowsy, don't drive or operate heavy machinery.


Skin changes such as rashes, redness, dryness, or itchiness are rather common. Your skin may lose part some of its color, turning lighter or yellowish. These side effects are normally minor. Tell your doctor or nurse if you have any of these symptoms. They can recommend creams or lotions you can use; also, they can prescribe drugs to relieve the itchiness.


Your mouth may become sore or dry or you may develop small ulcers during your treatment. Some find that sucking on ice can help. Drinking lots of fluids and regularly brushing your teeth gently using a soft-bristled toothbrush can help lower the risk of this happening. Tell your doctor or nurse if you have any of these problems, as they can prescribe a mouthwash and drugs to prevent infection in the mouth.


Some people lose their appetite. This can be mild and last for a few days. If it doesn't get better, request to see a dietitian or specialist nurse at your hospital. They can give you advice on how to improve your appetite and maintain a healthy weight.


Your doctor can prescribe antiemetic drugs to prevent or greatly reduce your nausea or vomiting. If your nausea remains uncontrolled or continues, tell your doctor.

Some of these drugs can cause constipation. Tell your doctor or nurse if this is a problem.


This is the most common side effect of temsirolimus, and it develops around a week after the treatment. Normally, this can be easily controlled with drugs, so tell your doctor if your diarrhea is severe or ongoing. It's important to drink lots of fluids if you have diarrhea.


Some people have swelling around the eyes, in the ankles, or in other areas of the body due to the build-up of fluid. This does no harm, though it can be bothersome and uncomfortable. Diuretics can help rid the body of some excess fluid, though often these fluids are eliminated by themselves. Tell your doctor if you experience rapid weight gain. This may be a sign that you are retaining fluids.


Temsirolimus can cause a temporary rise in blood sugar. You will have periodic blood tests to check on your blood sugar. The signs of raised blood sugar include a feeling of increased thirstiness, a need to urinate more frequently, and feeling hungry. If you have any of these symptoms, tell your doctor or nurse.

If you have diabetes, you may have to check your blood sugar levels more frequently. Talk to your doctor or nurse about how to manage this. You may need for your insulin dose to be changed.



Cancer increases the chances of blood clot (thrombosis), and temsirolimus can make this even more likely. A blood clot may cause symptoms such as pain, reddening or swelling in a leg, difficulty breathing, and pain in the chest. Get in touch with your doctor immediately if you have any of these symptoms. A blood clot is a serious matter, but your doctor can prescribe drugs to treat it.


You may be abnormally short of breath or have a cough. This is more likely if you have previous lung problems. Tell your doctor if this is the case.


Some people have abdominal pain or discomfort when they take temsirolimus. Tell your doctor if this happens. Normally, this can be easily controlled with drugs.

Rarely, temsirolimus can cause a hole (perforation) in the small intestine. Get in touch with your doctor immediately if you have severe pain in the abdomen or signs of bleeding such as anal bleeding, black-colored stool, or if you vomit blood (vomit that look like coffee grounds).


The level of cholesterol in your blood may rise. Your doctor will give you periodic blood tests to check on this.


You may notice you have pain in the back, muscles, and joints. Tell your doctor if you develop any of the following side effects, as they can prescribe medication to help.


Temsirolimus can cause insomnia in some people. Talk to your doctor or specialist nurse if you are having trouble sleeping.


Wounds may take longer to heal while you are being treated with temsirolimus. If you have any surgical procedures scheduled, you may have to stop taking temsirolimus before the operation and not start taking it again for a few weeks afterward. Talk to your doctor if this is the case for you.



Some drugs can interact with temsirolimus. This includes medications that can be purchased in a store or pharmacy. Tell your doctor if you are taking any medicines, including over-the-counter drugs, complementary therapies, vitamins, and herbal remedies. You should also avoid eating grapefruit or drinking grapefruit juice while taking temsirolimus.


Doctors still don't know how temsirolimus can affect your fertility. If this worries you, talk to your doctor before beginning treatment.


Your doctor will advise you not to become pregnant or have children during the treatment.


Women are recommended not to breastfeed during treatment and for a few months after chemotherapy has concluded. This is in case there is some trace of the drug left in your breast milk.


You should avoid having live vaccines during the treatment and for at least 12 months afterward. Live vaccines include BCG, yellow fever, measles, mumps, rubella, typhoid fever, and poliomyelitis.


If you need to go to the hospital for any reason not related to cancer, it is important that you tell your doctors and nurses caring for you that you are being treated with temsirolimus.

Always let your dentist know that you are taking the drug.