Trilaciclib (Cosela®)

Author: Karen Arnold-Korzeniowski, MSN RN
Content Contributor: Christine Cambareri PharmD, BCPS, BCOP
Last Reviewed: August 14, 2023

Pronounce: TRYE-la-SYE-klib

Classification: Kinase Inhibitor

About: Trilaciclib (Cosela®)

A kinase is an enzyme that promotes cell growth. There are many types of kinases, which control different phases of cell growth. Trilaciclib is not a cancer treatment, but a supportive care medicine. It is used to lessen bone marrow suppression (reduced blood counts) secondary to cancer and its cytotoxic treatments.

How to Take Trilaciclib (Cosela®)

This medication is given intravenously (IV, into a vein). The dose is determined by your size and how often you receive the medication will be decided by your provider.

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 medication 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, notify your care team immediately. Do not apply anything to the site unless instructed by your care team.

The blood levels of this medication can be affected by certain foods and medications, so they should be avoided. These include: dofetilide, dalfampridine, metformin, and cisplatin, among others. Therapy with trilaciclib can increase concentrations of these medications leading to side effects of the previously mentioned medications. Be sure to tell your healthcare provider about all medications and supplements you take.

Possible Side Effects

There are a number of things you can do to manage the side effects of trilaciclib. 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:


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.

Electrolyte Abnormalities

This medication can affect the normal levels of electrolytes (potassium, calcium, phosphate, etc.) in your body. Your levels will be monitored using blood tests. If your levels become too low, your care team may prescribe specific electrolytes to be given by IV or taken by mouth. Do not take any supplements without first consulting with your care team.

Less common, but important side effects include:

  • Lung Problems: Patients can develop an inflammation of the lungs (called pneumonitis) or interstitial lung disease that causes lung scarring while taking this medication. Notify your oncology care team right away if you develop any new or worsening symptoms, including shortness of breath, trouble breathing, cough, or fever.
  • Allergic Reaction: In some cases, patients can have an allergic reaction to this medication. Signs of a reaction can include: swelling, shortness of breath or difficulty breathing, chest pain, rash, flushing or itching, or a decrease in blood pressure. If you notice any changes in how you feel during the infusion, let your nurse know immediately. The infusion will be slowed or stopped if this occurs.

Reproductive Concerns

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 3 weeks after treatment. Even if your menstrual cycle stops or you believe you are not producing sperm, you could still be fertile and conceive. You should not breastfeed while receiving this medication or for 3 weeks after your last dose.