Buserelin Acetate Spray - Nasal

Pronunciation: BUE-se-REL-in AS-e-tate

Common Brand Name(s): Suprefact

Important: How To Use This Information

This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.


Buserelin is used in men to treat advanced prostate cancer. It is not a cure. Most types of prostate cancer need the male hormone testosterone to grow and spread. This medication works by reducing the amount of testosterone that the body makes. This effect helps slow or stop the growth of cancer cells and helps relieve symptoms such as painful/difficult urination. Talk to your doctor about the risks and benefits of treatment.

Buserelin is also used in women to treat a condition in which the tissue that normally lines the inside of the uterus also grows outside the uterus (endometriosis). It works by reducing the amount of the female hormone estrogen that the body makes. This effect helps to shrink the abnormal tissue and reduce the symptoms of endometriosis (e.g., pelvic pain, painful menstrual cramps).

Buserelin is a man-made hormone that is similar to a natural hormone made by the body (gonadotropin-releasing hormone-GnRH).

How To Use

Read the Patient Information Leaflet provided by your pharmacist before you start using this drug and each time you get a refill. If you have any questions, consult your doctor or pharmacist.

Learn all usage instructions. Follow the directions on how to properly prime the bottle if you are using it for the first time or if you have not used it in a while.

Gently blow your nose before using this drug. Use this medication by spraying it into your nose, usually 3 times a day or as directed by your doctor. Avoid spraying this medication in your eyes.

Buserelin works best when the amount of medicine in your body is kept at a constant level. Therefore, use this drug regularly at evenly spaced intervals. To help you remember, use it at the same times each day.

The length of treatment for women with endometriosis is usually 6 months, and treatment should last no longer than 9 months unless otherwise directed by your doctor. Do not use this drug for longer than prescribed because the risk of serious side effects may be increased.

Tell your doctor if your condition does not improve or if it worsens.

Side Effects

Hot flashes (flushing), irritation inside the nose, headache, decreased sexual interest/ability, swelling ankles/feet, upset stomach, joint pain, dizziness, mood swings, vaginal dryness, increased menstrual bleeding, breast pain/swelling, or acne may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

In women who use this medication regularly, the menstrual period is expected to stop (or decrease to light bleeding/spotting) within the first 2 months. Tell your doctor promptly if regular periods continue after 2 months of treatment with buserelin.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

During the first few weeks of treatment, your hormone levels will actually increase before they decrease. This is your body's normal response to this drug. Therefore, your symptoms may get worse for a few weeks when you first start treatment. If your symptoms do not improve after this time, consult your doctor promptly.

In men with prostate cancer that has spread to the spine or caused urinary blockage, your doctor may need to monitor your condition more closely, especially during the first few weeks of treatment. Tell your doctor right away if any of the following serious symptoms occur or worsen:

  • bone pain
  • numbness/tingling/weakness of the arms/legs
  • blood in the urine
  • painful/difficult urination
  • unusual weakness
  • inability to move

Tell your doctor right away if any of these unlikely but serious side effects occur:

  • mental/mood changes (e.g., depression)
  • new/worsening bone pain
  • broken bones

Seek immediate medical attention if any of these rare but very serious side effects occur:

  • chest/jaw/left arm pain
  • trouble breathing
  • weakness on one side of the body
  • slurred speech
  • fast/irregular heartbeat
  • severe dizziness
  • fainting

Rarely, a very serious problem with your pituitary gland (pituitary apoplexy) may occur, usually 1 hour to 2 weeks after your first dose of this medication. Seek immediate medical attention if any of these very serious side effects occur:

  • sudden severe headache
  • sudden severe mental/mood changes (e.g., severe confusion, difficulty concentrating)
  • vision changes
  • severe vomiting

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including:

  • rash
  • itching/swelling (especially of the face/tongue/throat)
  • severe dizziness
  • trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.


Before using buserelin, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have:

  • unexplained abnormal vaginal bleeding

This medication should not be used if you have a type of prostate cancer that is not sensitive to testosterone or if your testicles have been removed.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

  • heart disease (such as heart attack)
  • stroke
  • high cholesterol

If buserelin is used for a long time, it may weaken your bones and increase your risk for bone loss (osteoporosis). Before using this medication, tell your doctor or pharmacist if you have osteoporosis or if you have any of the following risk factors:

  • long-term alcohol use
  • smoking
  • family history of osteoporosis and broken bones
  • use of certain medications (including corticosteroids such as prednisone, certain anti-seizure drugs such as phenytoin)

Buserelin may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.

The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using buserelin, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions:

  • certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG)
  • family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death)

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using buserelin safely.

If you have high blood pressure, this medication may increase your blood pressure. If you have diabetes, buserelin may increase blood sugar levels, leading to symptoms such as increased thirst/urination. If you have high blood pressure or diabetes, tell your doctor or pharmacist because closer monitoring of your condition may be needed.

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Older adults may be more sensitive to the side effects of this drug, especially QT prolongation (see above).

In men, use of this medication for a long time may make the testicles unable to produce testosterone or sperm. It is not known if these effects go away in all men after the medication is stopped. However, these effects alone should not be considered a reliable form of birth control. Discuss the use of reliable forms of birth control (such as condoms) with your doctor to prevent pregnancy.

This medication must not be used during pregnancy. It may harm an unborn baby. Women should start this medication on day 1 or 2 of their menstrual period. During treatment, this medication should stop the release of an egg (ovulation) and your periods, but this should not be used as a reliable method of birth control. Discuss the use of reliable non-hormonal forms of birth control (such as condoms, diaphragm with spermicide) with your doctor. If you become pregnant or think you may be pregnant, tell your doctor right away.

Small amounts of this medication pass into breast milk. Because of the possible risk to the infant, breast-feeding is not recommended while using this drug. Consult your doctor before breast-feeding.

Drug Interactions

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.


If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.


Do not share this medication with others.

Laboratory and/or medical tests (e.g., hormone levels, PSA blood test for men, bone tests) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

Missed Dose

It is important that you do not miss any doses. However, if you miss a dose, use it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Use your next dose at the regular time. Do not double the dose to catch up.

Missed doses may allow ovulation to resume in women, increasing the risk of becoming pregnant. Consult your doctor for more information.


Store the container upright at room temperature away from heat and light. Do not freeze. After first opening the product, it may be kept up to 5 weeks before it must be discarded. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Is it an emergency?

If you or someone in your care has chest pains, difficulty breathing, or severe bleeding, it could be a life-threatening emergency. Call 9-1-1 or the local emergency number immediately.
If you are concerned about a possible poisoning or exposure to a toxic substance, call Poison Control now at 1-800-567-8911.

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