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Firmagon Side Effects

Generic Name: degarelix

Note: This page contains information about the side effects of degarelix. Some of the dosage forms included on this document may not apply to the brand name Firmagon.

For the Consumer

Applies to degarelix: subcutaneous powder for solution

In addition to its needed effects, some unwanted effects may be caused by degarelix (the active ingredient contained in Firmagon). In the event that any of these side effects do occur, they may require medical attention.

If any of the following side effects occur while taking degarelix, check with your doctor or nurse immediately:

More common:
  • Back pain
  • blurred vision
  • dizziness
  • fever
  • flushing or redness of the skin
  • hard lump
  • headache
  • nervousness
  • pain
  • pounding in the ears
  • slow or fast heartbeat
  • small lumps under the skin
  • swelling
  • unusually warm skin
Less common:
  • Bladder pain
  • bloody or cloudy urine
  • chills
  • decrease in testicle size
  • decreased interest in sexual intercourse
  • difficult, burning, or painful urination
  • difficulty in moving
  • frequent urge to urinate
  • inability to have or keep an erection
  • increased sweating
  • loss in sexual ability, desire, drive, or performance
  • lower back or side pain
  • muscle pain or stiffness
  • pain in the joints
  • Chest pain or discomfort
  • fainting
  • irregular heartbeat
  • pounding heartbeat
  • shortness of breath

Minor Side Effects

Some of the side effects that can occur with degarelix may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Difficulty having a bowel movement (stool)
  • feeling of warmth
  • increased weight
  • redness of the face, neck, arms, and occasionally, upper chest
  • sudden sweating
  • unusual tiredness or weakness
Less common:
  • Diarrhea
  • lack or loss of strength
  • nausea
  • night sweats
  • sleeplessness
  • swelling of the breasts or breast soreness
  • trouble sleeping
  • unable to sleep

For Healthcare Professionals

Applies to degarelix: subcutaneous powder for injection


Very common (10% or more): Increased liver transaminases (47%), increased gamma-glutamyltransferase (10%)
Uncommon (0.1% to 1%): Increased bilirubin, increased alkaline phosphatase[Ref]


Very common (10% or more): Injection site reaction (including pain, erythema, swelling, induration, nodule; 44%), pyrexia (10%), fatigue (10%)
Common (1% to 10%): Chills, asthenia, influenza-like illness[Ref]


Very common (10% or more): Decreased hematocrit (40%), decreased hemoglobin (15%)
Common (1% to 10%): Anemia
Rare (less than 0.1%): Neutropenic fever[Ref]


Very common (10% or more): Hot flush (26%), QT/QTc interval prolongation (20%)
Common (1% to 10%): Hypertension
Uncommon (0.1% to 1%): Cardiac arrhythmia (including atrial fibrillation), palpitations, vasovagal reaction (including hypotension)
Rare (less than 0.1%): Myocardial infarction, cardiac failure[Ref]


Very common (10% or more): Abnormal BUN (15%)
Common (1% to 10%): Abnormal creatinine level
Uncommon (0.1% to 1%): Renal impairment[Ref]


Very common (10% or more): Increased weight (11%), decreased weight (10%)
Common (1% to 10%): Abnormal potassium level
Uncommon (0.1% to 1%): Hyperglycemia/diabetes mellitus, increased cholesterol, decreased appetite, blood calcium changes[Ref]


Very common (10% or more): Antibody formation (10%)[Ref]


Common (1% to 10%): Hyperhidrosis (including night sweats), rash
Uncommon (0.1% to 1%): Urticaria, skin hyperpigmentation, skin nodule, alopecia, pruritus, erythema[Ref]


Common (1% to 10%): Nausea, constipation, diarrhea
Uncommon (0.1% to 1%): Vomiting, abdominal pain, abdominal discomfort, dry mouth[Ref]


Common (1% to 10%): Urinary tract infection, gynecomastia, testicular atrophy, erectile dysfunction
Uncommon (0.1% to 1%): Pollakiuria, micturition urgency, dysuria, nocturia, incontinence, testicular pain, breast pain, pelvic pain, genital irritation, ejaculation failure[Ref]


Common (1% to 10%): Back pain, arthralgia, musculoskeletal pain and discomfort
Uncommon (0.1% to 1%): Osteoporosis/osteopenia, arthralgia, muscular weakness, muscle spasms, joint swelling/stiffness[Ref]

Nervous system

Common (1% to 10%): Dizziness, headache
Uncommon (0.1% to 1%): Mental impairment, hypoesthesia[Ref]


Common (1% to 10%): Insomnia
Uncommon (0.1% to 1%): Loss of/decreased libido, depression[Ref]


Uncommon (0.1% to 1%): Hypersensitivity reaction
Postmarketing reports: Anaphylaxis, angioedema[Ref]


Uncommon (0.1% to 1%): Blurred vision[Ref]


Uncommon (0.1% to 1%): Dyspnea[Ref]


1. "Product Information. Firmagon (degarelix)." Ferring Pharmaceuticals Inc, Tarrytown, NY.

2. Cerner Multum, Inc. "Australian Product Information." O 0

3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

Not all side effects for Firmagon may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.