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Overview: Trelstar is commonly used to treat cancer. Common side effects include hot flashes, bone pain, and headache. Call your health care provider right away if you have chest pain, seizures, or problems with your vision. Trelstar is an injection given into a muscle by a health care provider.

Uses

What is Trelstar used for?

Trelstar (triptorelin) is commonly used to treat certain prostate cancers.

Trelstar may also be used for other conditions as determined by your health care provider.

See also: Triptodur

How does Trelstar work (mechanism of action)?

Trelstar works by lowering the levels of a certain hormone called testosterone in the body. Some types of prostate cancer need testosterone in order for the cancer cells to grow. Trelstar lowers the amount of testosterone to starve these cancer cells, which can stop their growth and shrink tumors.

How is Trelstar supplied (dosage forms)?

Brands and other names

  • Trelstar

Dosage forms and strengths

Trelstar is available in an injectable form that is given by a health care provider.

How should I store Trelstar?

Trelstar is usually given by a health care provider in a hospital or clinic. You will not store it at home.

Side Effects

What are the most common side effects of Trelstar?

The most common side effects of Trelstar are listed below. Tell your health care provider if you have any of these side effects that bother you.

  • Hot flashes
  • Bone pain
  • Headache
  • Fluid retention in legs
  • Leg pain
  • Inability to get or keep an erection
  • Testicle shrinkage

There may be other side effects of Trelstar that are not listed here. Contact your health care provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of Trelstar?

While less common, the most serious side effects of Trelstar are described below, along with what to do if they happen.

Severe Allergic Reactions. Trelstar may cause allergic reactions, which can be serious. Get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Tumor Flare. During the first weeks of treatment, Trelstar can temporarily cause your tumor to grow or cause your cancer symptoms to get worse, which is called a tumor flare. Call your health care provider right away if you have any of the following symptoms of a tumor flare.

  • Bone pain
  • Pain, tingling, or numbness in the hands and feet
  • Blood in your pee
  • Trouble passing urine or change in the amount of urine

High Blood Sugar. Trelstar may increase your blood sugar levels and increase your risk of developing diabetes. Talk to your health care provider about how to maintain healthy blood sugar levels. Keep all appointments with your health care provider to check your blood tests. Call your health care provider if you have the following symptoms of high blood sugar.

  • Thirstier than usual
  • Peeing more than usual
  • Increase in hunger
  • Tiredness
  • Feeling sick to your stomach
  • Confusion
  • Fruity smelling breath

High Levels of Fat in the Blood (Hyperlipidemia). Trelstar can cause high levels of fats in your blood. You usually do not have symptoms right away, but over time, high levels of fats can cause damage to your heart. Keep all of your appointments with your health care provider to get your blood checked while using Trelstar.

Heart Attack and Stroke. Trelstar can increase your risk of a heart attack or stroke that can lead to death. This risk is higher in people who already have heart disease. It also increases with longer use of Trelstar and higher doses. Do not use Trelstar if you have had a recent heart attack without talking to your health care provider. This could increase your risk of having another heart attack. Get emergency help if you have any of the following symptoms of a heart attack or stroke.

  • Chest pain or pressure
  • Fast or abnormal heartbeat
  • Trouble breathing
  • Pain in your back, jaw, throat, or arm
  • Sweating, upset stomach, vomiting, or dizziness
  • Sudden weakness on one side of your body
  • Sudden and severe headache
  • Slurred speech or trouble understanding speech

Seizures. Some people who have used Trelstar have reported having seizures. There are many different types of seizures and some of them are not easy to recognize. Call your health care provider if you have any of the following signs that a seizure is happening or could happen.

  • Muscle twitching, jerking, spasms, tremors, or other uncontrolled movements
  • Stiffening of your arms and legs
  • Feeling anxious, nervous, confused, or a sense of dread
  • Feeling dizzy or lightheaded
  • Falling or losing consciousness

Heart Rhythm Changes. Trelstar may cause a rare, dangerous heart rhythm problem called QT prolongation and torsade de pointes. Some people have a higher risk of this, including people who are older, have other people in their family who have had these conditions, have low potassium or magnesium levels, or take medicines that can prolong the QT interval. Tell your health care provider right away if you faint or have changes in your heart rate or rhythm, such as a fast or skipping heartbeat.

Warnings & Precautions

Who should not use Trelstar?

Allergies to Ingredients. People who are allergic to any of the following should not use Trelstar.

  • Trelstar
  • Triptorelin
  • Any other GnRH agonists
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in Trelstar.

What should I know about Trelstar before using it?

Do not use Trelstar unless it has been prescribed to you by a health care provider. Trelstar is usually given by a health care provider in a hospital or clinic. 

Trelstar can alter test results in pituitary-gonadotropic and hormone function tests while you are using the medicine and even after your last dose. Tell any health care provider you are seeing that you are using Trelstar.

What should I tell my health care provider before using Trelstar?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if Trelstar is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your health care provider if you have any of the following.

  • Diabetes or high blood sugar
  • Heart problems, including long QT syndrome
  • Liver problems
  • Kidney problems
  • High fat levels in your blood
  • History of seizures
  • Any other conditions that affect your metabolism

Pregnancy. People who can become pregnant are not usually prescribed Trelstar. 

Breastfeeding. People who can breastfeed are not usually prescribed Trelstar.

Infertility. Trelstar may cause infertility. Talk to your health care provider if this is a concern for you.

How can I get more information about Trelstar?

For more information about Trelstar, you can visit the drugmaker’s website at www.trelstar.com or call them at 844-837-4891.

Interactions

Does Trelstar interact with foods or drinks?

There are no known interactions between Trelstar and foods or drinks.

It is unknown if drinking alcohol will affect Trelstar, but heavy drinking can slow your immune response and make it harder for your body to fight cancer.

Does Trelstar interact with other medicines (drug interactions)?

There are no known interactions between Trelstar and other medicines. Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much Trelstar?

If you or someone else has used too much Trelstar, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of Trelstar?

Trelstar is usually given by a health care provider in a hospital. Your health care provider will make sure you are receiving Trelstar as scheduled.

If you miss an appointment to get your Trelstar dose, call to make another appointment as soon as possible.