degarelix(redirected from Firmagon)
Binds reversibly to the pituitary GnRH receptors, thereby reducing the release of gonadotropins and consequently testosterone
Powder for injection: 80 mg/vial, 120 mg/vial
Indications and dosages
➣ Advanced prostate cancer
Adults: Initially, 240 mg subcutaneously given as two injections of 120 mg each, followed by maintenance dose of 80 mg subcutaneously as a single injection every 28 days
• Hypersensitivity to drug or its components
• Females of childbearing potential
Use cautiously in:
• moderate or severe renal impairment (creatinine clearance less than 50 ml/minute)
• severe hepatic dysfunction
• congenital long QT syndrome, electrolyte abnormalities, congestive heart failure, and in patients taking Class IA (such as quinidine, procainamide) or Class III (such as amiodarone, sotalol) antiarrhythmics
• children (safety and efficacy not established).
• Be aware that drug is intended for deep subcutaneous administration only and isn't to be administered I.V.
• Wear gloves during preparation and administration.
• Reconstitute powder with sterile water for injection. Don't use other solutions.
• Be aware that the treatment initiation pack contains two vials of Firmagon 120 mg that must be prepared for two subcutaneous injections; therefore, the instructions below need to be repeated a second time.
• For initial 120-mg dose, draw up 3 ml sterile water for injection using supplied reconstitution needle (21G, 2 inches) and slowly inject sterile water for injection into 120-mg vial to yield a concentration of 40 mg/ml.
• For 80-mg maintenance dose, draw up 4.2 ml sterile water for injection using supplied reconstitution needle (21G, 2 inches) and slowly inject sterile water for injection into 80-mg vial to yield a concentration of 20 mg/ml.
• Hold vial upright and swirl it very gently until liquid is clear and without undissolved powder or particles. If powder adheres to vial over the liquid surface, vial can be tilted slightly to dissolve powder. Don't shake vial, to prevent foam formation. A ring of small air bubbles on the surface of the liquid is acceptable. The reconstitution procedure may take up to 15 minutes.
• Tilt vial slightly and keep needle in lowest part of vial. Withdraw 3 ml of drug (120-mg dose) and 4 ml (80-mg dose) without turning vial upside down.
• Exchange reconstitution needle with administration needle for deep subcutaneous injection (27G, 1¼ inches). Remove any air bubbles.
• Use reconstituted drug within 1 hour after addition of sterile water for injection.
• Give injection in abdomen in area that won't be exposed to pressure (such as not close to waistband or belt or close to ribs).
CNS: fatigue, asthenia, dizziness, headache, insomnia
CV: hypertension, prolonged QT interval
GI: nausea, constipation
GU: urinary tract infection
Hepatic: abnormal hepatic function
Musculoskeletal: decreased bone density (with long-term therapy), back pain, arthralgia
Other: injection-site reactions, hot flashes, weight gain, fever, chills, night sweats, anti-degarelix antibody development
Drug-diagnostic tests. Gammaglutamyltransferase, serum transaminases: increased levels
• Monitor renal and hepatic function tests closely.
Monitor patient on long-term androgen deprivation therapy for prolonged QT interval.
• Monitor testosterone concentration monthly until medical castration is achieved in patients with hepatic impairment; then consider every-other-month testosterone concentration measurement.
• Because this drug may suppress pituitary gonadal system, periodically monitor drug's therapeutic effect by measuring serum concentration of prostate-specific antigen (PSA). If PSA increases, measure serum testosterone concentration.
• Advise patient to make sure injection site is free of pressure from belts, waistbands, or other types of clothing.
Instruct patient to immediately report abnormal heartbeats, dizziness, or faintness.
• Tell patient that drug isn't indicated for use in women.
• Inform patient of possible adverse effects of androgen deprivation (hot flashes, skin flushing, increased weight, decreased sex drive, erectile dysfunction).
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the tests mentioned above.
Pharmacologic: gnrh antagonist
Time/action profile (decrease in testosterone levels)
|SC||within 1 wk||2 wk||1 mo|
Adverse Reactions/Side Effects
Central nervous system
- ↑ liver enzymes (most frequent)
- erectile dysfunction
- testicular atrophy
- pituitary gonadal suppression
- injection site reactions (most frequent)
- hot flashes (most frequent)
- weight gain (most frequent)
- ↓ bone density
- hypersensitivity reactions including anaphylaxis, angioedema, and urticaria (life-threatening)
Drug-Drug interactionConcurrent use with class IA antiarrhythmics, including procainamide and quinidine or class III antiarrhythmics including amiodarone or sotalol may ↑ risk of QT prolongation and serious arrhythmias.
- Assess patient for hot flashes and other side effects.
- Monitor for signs and symptoms of hypersensitivity reactions (rash, wheezing, shortness of breath). Treat symptomatically and discontinue degarelix if symptoms occur.
- Lab Test Considerations: Measure serum prostate-specific antigen (PSA) periodically to determine effect. If PSA ↑, measure serum testosterone concentrations.
- May effect pituitary gonadotropic or gonadal functions.
Potential Nursing DiagnosesSexual dysfunction (Side Effects)
- Subcutaneous: Reconstitute each 120-mg vial with 3 mL and each 80-mg vial with 4.2 mL sterile water using 21 gauge, 2-inch reconstitution needle. Keep vial upright and swirl very gently until liquid is clear, without undissolved powder or particles. If powder adheres to vial over the liquid surface, vial can be tilted slightly to dissolve powder. Avoid shaking to prevent foam; ring of small air bubbles on surface of liquid is acceptable. Tilt vial slightly, keeping needle in lowest part of vial and withdraw 3 mL for 120-mg dose or 4 mL for 80-mg dose. Exchange reconstitution needle for 27 gauge, 1 1/4-inch administration needle. Remove air bubbles. Grasp abdominal skin and insert needle deeply at angle not <45°. Inject in an area free of pressure from belts, waistbands, or other types of clothing. Administer immediately after reconstitution. If administering 240-mg loading dose, repeat 120-mg injection for the second dose.
- Explain purpose of medication to patient. Instruct patient to notify health care professional if an injection is missed. Advise patient to read Patient Labeling carefully.
- Inform patient of possible side effects (hot flashes, flushing, increased weight, decreased sex drive, erectile dysfunction). Advise patient that redness, swelling, and itching at injection site is usually mild, self-limiting, and decreases within 3 days.
- Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications.
- Advise female patient that women who are pregnant or who plan to become pregnant or breast feed should not take degarelix.
- Decrease in the spread of prostate cancer.