Gemcitabine chemotherapy is used to treat advanced cancers of the breast, ovaries, pancreas, and lungs. It works by disrupting DNA replication, which inhibits a cell’s ability to divide and multiply.

Chemotherapy, also called “chemo,” is a type of cancer treatment that uses drugs to disrupt the growth and division of cancer cells.

There are many different chemo drugs. One of these is gemcitabine (Gemzar), which is used to treat a variety of cancers.

In this article, we take a closer look at gemcitabine chemo, how it works, its potential side effects, and more.

Gemcitabine (Gemzar) is a type of chemo drug that belongs to a class of drugs called antimetabolites. Antimetabolites disrupt DNA replication, which a cell needs to do in order to divide.

Gemcitabine works by mimicking a normal building block of DNA, called a nucleotide. However, because gemcitabine is a faulty nucleotide, it hampers the DNA replication process when it’s added to a growing DNA strand.

When a cell cannot copy its DNA, it cannot split into two. As such, cells that have been treated with gemcitabine end up dying.

Gemcitabine also inhibits an enzyme that’s important for making nucleotides that are used in DNA. When this happens, a cell tries to gather more nucleotide ingredients from its outside environment in order to compensate. This means that it also takes up more gemcitabine, increasing the drug’s effects in the cell.

Gemcitabine is approved by the Food and Drug Administration (FDA) for the treatment of:

Generally speaking, gemcitabine is used for advanced cancers. Advanced cancers are those that have spread to nearby lymph nodes or tissues or to more distant parts of the body.

Most of the time, gemcitabine is used in combination with another type of chemo drug. This is called combination chemo. However, it may be used as a single-agent treatment for pancreatic cancer.

Gemcitabine is given directly into a vein. This is called intravenous (IV) administration. It typically takes about 30 minutes to receive an infusion of gemcitabine.

While it’s possible that you may get gemcitabine through an IV inserted into your hand or arm, you may also receive it through a catheter that goes directly to a large vein in your chest. Some examples include a PICC line or a port.

Like other types of chemo, gemcitabine is given in cycles where there’s a period of active treatment followed by a period of rest. This resting time allows your body to recover from the effects of gemcitabine.

A cycle of gemcitabine is typically 3 or 4 weeks long, depending on the type of cancer that’s being treated. You receive gemcitabine once each week for 2 or 3 weeks. You’ll receive no gemcitabine for the last week in the cycle.

The exact number of cycles used can depend on your specific situation. Be sure to ask your care team about how long you can expect to be receiving treatment with gemcitabine.

Gemcitabine acts on cells that are in the process of growing and dividing. While this includes cancer cells, other healthy quick-growing cells in the body, such as those in the bone marrow, hair follicles, and digestive tract, can also be affected.

Because of this, gemcitabine has a variety of side effects, some of the most common of which include:

Gemcitabine also affects liver and kidney function. This can lead to elevated liver enzymes and blood or protein in your urine. Your doctor will perform periodic tests that assess the function of your liver and kidneys.

It’s always important to let your care team know about the side effects you’re having. It’s possible that they can give you some tips to help manage them. Always reach out to your care team if you have side effects that:

  • are severe
  • get worse or don’t get better with at-home care
  • are associated with signs of an infection, such as fever, chills, or cough

According to the prescribing information, gemcitabine can improve progression-free survival, time to progression, and overall survival when used as directed. The exact effectiveness statistics depend on the type of cancer it’s used for.

Overall, there are many factors that can impact the effectiveness of chemo. These include:

  • the specific type of cancer
  • the extent of the cancer (stage)
  • how fast the cancer is growing and spreading
  • whether the cancer has certain markers or genetic changes
  • how the cancer responds to the chemo
  • your age and overall health

Researchers continue to study ways to make gemcitabine therapy more effective. These new innovations are tested through clinical trials.

For example, a phase II clinical trial of gemcitabine with targeted therapy drugs improved progression-free survival in people with HER2-postive metastatic breast cancer.

Another recent review of trials found that combining gemcitabine with another chemo drug called capecitabine (Xeloda) improved outcomes for pancreatic cancer.

Can certain medications interact with gemcitabine chemotherapy?

Yes, it’s possible that some medications may interact with gemcitabine. Before starting on gemcitabine, be sure to give your doctor detailed information about any of the following things you may take:

  • prescription medications
  • over-the-counter medications
  • vitamins and supplements
  • herbal remedies

Can you have gemcitabine chemotherapy if you’re pregnant or breastfeeding?

Gemcitabine may harm a developing fetus and should not be used during pregnancy. It’s also vital to talk with your care team about contraception strategies while undergoing treatment.

Breastfeeding while having chemo isn’t typically recommended. It’s possible that the drug may pass to an infant through breast milk.

Is it OK to have vaccines if you’re having gemcitabine chemotherapy?

In general, inactivated, non-live vaccines (such as the COVID-19 vaccine and the flu shot) are safe and recommended during chemotherapy.

Live vaccines (that contain a weakened version of the virus or bacteria), such as chickenpox and rubella, aren’t typically recommended during chemo. This is because your immune response to them may not be as good.

If you’re undergoing chemotherapy treatment, it’s a good idea to check with your doctor before scheduling a vaccine.

How long does it take gemcitabine chemotherapy to work?

The answer to this question depends on many factors. These factors include but aren’t limited to: the type of cancer, its stage, and your age or overall health.

For some people, treatment may begin to work quickly. However, for others, it may take several cycles. Your care team can use a variety of tests to measure how your cancer is responding to treatment.

Does gemcitabine chemotherapy have any long-term side effects?

It’s possible that treatment with gemcitabine may impact your fertility going forward. Because of this, it’s important to talk with your care team about fertility-preserving strategies, such as storing sperm or eggs, before starting treatment.

Gemcitabine is a chemo drug that may be used for advanced cancers of the breast, lungs, ovaries, and pancreas. It works by interfering with DNA replication in rapidly dividing cells.

Like many chemo drugs, gemcitabine has side effects. These can include low blood cell counts, hair loss, and nausea and vomiting. Talk with your care team about how to manage side effects due to gemcitabine.

Gemcitabine can improve cancer outlook. However, because outlook depends on many factors specific to the cancer and you as an individual, be sure to have an open discussion with your care team about what to expect from gemcitabine therapy.