Topotecan works by blocking an enzyme in cells called topoisomerase, which is necessary for cell replication and tumor growth. Cells need this enzyme to keep their DNA in the correct shape when they are dividing. Blocking this enzyme leads to breaks in the DNA, which leads to cancer cells dying.

How to Take Topotecan

Topotecan is given intravenously (into a vein) or orally (by mouth). This sheet focuses on topotecan given intravenously (IV). The amount given and schedule are based on the person’s size, type of cancer, and regimen being used.

Even when carefully and correctly administered by trained personnel, this drug may cause a feeling of burning and pain. There is a risk that this drug may leak out of the vein at the injection site, resulting in tissue damage that can be severe. If the area of injection becomes red, swollen, or painful at any time during or after the injection, tell your doctor or nurse immediately. Do not apply anything to the site unless told to by your doctor or nurse.

This medication can cause neurologic side effects. Use caution when driving or operating heavy machinery until you know how this medication affects you.

Possible Side Effects of Topotecan

There are a number of things you can do to manage the side effects of topotecan. Talk to your care team about these recommendations. They can help you decide what will work best for you. These are some of the most common or important side effects:

Low White Blood Cell Count (Leukopenia or Neutropenia)

White blood cells (WBC) are important for fighting infection. While receiving treatment, your WBC count can drop, putting you at a higher risk of getting an infection. You should let your doctor or nurse know right away if you have a fever (temperature greater than 100.4°F/38°C), sore throat or cold, shortness of breath, cough, burning with urination, or a sore that doesn't heal. This medication can cause a rare complication called neutropenic colitis, which is a serious infection of the bowel. If you have abdominal pain, contact your care team immediately.

Tips to preventing infection:

Washing hands, both yours and your visitors, is the best way to prevent the spread of infection.
Avoid large crowds and people who are sick (i.e.: those who have a cold, fever or cough or live with someone with these symptoms).
When working in your yard, wear protective clothing including long pants and gloves.
Do not handle pet waste.
Keep all cuts or scratches clean.
Shower or bathe daily and perform frequent mouth care.
Do not cut cuticles or ingrown nails. You may wear nail polish, but not fake nails.
Ask your oncology care team before scheduling dental appointments or procedures.
Ask your oncology care team before you, or someone you live with has any vaccinations.

Low Platelet Count (Thrombocytopenia)

Platelets help your blood clot, so when the count is low you are at a higher risk of bleeding. Let your oncology care team know if you have any excess bruising or bleeding, including nose bleeds, bleeding gums or blood in your urine or stool. If the platelet count becomes too low, you may receive a transfusion of platelets.

Do not use a razor (an electric razor is fine).
Avoid contact sports and activities that can result in injury or bleeding.
Do not take aspirin (salicylic acid), non-steroidal, anti-inflammatory medications (NSAIDs) such as Motrin/Advil (ibuprofen), Aleve (naproxen), Celebrex (celecoxib) etc. as these can all increase the risk of bleeding. Please consult with your healthcare team regarding use of these agents and all over-the-counter medications/supplements while on therapy.
Do not floss or use toothpicks and use a soft-bristle toothbrush to brush your teeth.

Less common but important side effects can include:

Lung changes: This medication can cause interstitial lung disease. Report any new or worsening shortness of breath, cough, or fever to your healthcare provider.
Fatigue: Fatigue is very common during cancer treatment and is an overwhelming feeling of exhaustion that is not usually relieved by rest. While on cancer treatment, and for a period after, you may need to adjust your schedule to manage fatigue. Plan times to rest during the day and conserve energy for more important activities. Exercise can help combat fatigue; a simple daily walk with a friend can help. Talk to your healthcare team for helpful tips on dealing with this side effect.
Nausea and/or Vomiting: Talk to your oncology care team so they can prescribe medications to help you manage nausea and vomiting. In addition, dietary changes may help. Avoid things that may worsen the symptoms, such as heavy or greasy/fatty, spicy, or acidic foods (lemons, tomatoes, oranges). Try saltines, or ginger ale to lessen symptoms. Call your oncology care team if you are unable to keep fluids down for more than 12 hours or if you feel lightheaded or dizzy at any time.

Sexual & Reproductive Concerns

This medication may affect your reproductive system, resulting in the menstrual cycle or sperm production becoming irregular or stopping permanently. Women may experience menopausal effects including hot flashes and vaginal dryness. In addition, the desire for sex may decrease during treatment. You may want to consider sperm banking or egg harvesting if you may wish to have a child in the future. Discuss these options with your oncology team.

Exposure of an unborn child to this medication could cause birth defects, so you should not become pregnant or father a child while on this medication. Effective birth control is necessary during treatment and for at least six months for women and three months for men after treatment, even if your menstrual cycle stops or you believe you are not producing sperm. You should not breastfeed while receiving this medication or for 1 week after your last dose.