Names and pronunciation
(day-gah-rel′iks) Firmagon
PDF page 358
Loading InternPractice…
Drug reference
(day-gah-rel′iks) Firmagon
PDF page 358
Func. class.: Antineoplastic
PDF page 358
Chem. class.: GnRH-receptor antagonist
PDF page 358
ACTION: Reduces release of gonado- tropins and testicular steroidogenesis by reversibly binding to GnRH receptors
PDF page 358
USES: Advanced prostate cancer
PDF page 358
CONTRAINDICATIONS: Hyper- sensitivity, QT prolongation, osteoporosis, severe hepatic/renal disease, pregnancy, breastfeeding Precautions: CV disease, electrolyte abnormalities, geriatric patients
PDF page 358
SIDE EFFECTS CNS: Chills, dizziness, fatigue, fever, headache, insomnia CV: Increased QT prolongation, hypoten- sion, hot flashes, hypertension GI: Diarrhea, constipation, nausea GU: ED, UTI, gynecomastia, testicular atrophy INTEG: Injection site reactions, pain at site, redness, swelling MS: Back pain, decreased bone density SYST: Hypersensitivity, anaphylaxis, angioedema
PDF pages 358, 359
INTERACTIONS Increase: QT prolongation—class IA/III antidysrhythmics, methyldopa, metoclo- pramide, reserpine, avoid using together Drug/Lab Test Increase: PSA, LFTs, GGT Decrease: bone density test
PDF page 359
DOSAGE AND ROUTES • Adult (male): SUBCUT 240 mg given as two 120-mg injections (40 mg/mL concentrations); maintenance 80 mg (20 mg/mL concentration) every 28 days, starting 28 days after first dose
PDF page 358
Available forms: Injection 80, 120 mg vial
PDF page 358
Administer: • Do not give IV, SUBCUT only • Use double gloves, gown, aseptic tech- nique during preparation and adminis- tration, all safe handling procedures • Keep vials vertical; do not shake the vi- als; give reconstituted drug within 1 hr af- ter addition of sterile water for injection Reconstitution of 120-mg vial (240-mg dose only ): • Use two 120-mg vials; repeat for each 120-mg vial: draw up 3 mL of sterile water for injection with a 2-inch, 21-G needle; do not use bacteriostatic water for injection; inject the sterile water slowly, swirl gently; reconstitution can take up to 15 min; avoid turning the vial upside down; repeat with a new vial, needle, and syringe for the second 120-mg dose (total dose = 240 mg) Reconstitution of 80-mg vial: • Use 4.2 mL of sterile water for injection with a 2-inch, 21-G needle; do not use bacte- riostatic water for injection; inject the sterile water slowly into vial containing 80 mg; swirl gently; reconstitution can take up to 15 min; withdraw 4 mL (20 mg/mL); avoid turning upside down during withdrawal SUBCUT injection: • Exchange the reconstitution needle with a 1.25-inch, 27-G needle; remove air bubbles; give in the abdominal region; rotate injection site periodically; use area not exposed to pressure; grasp aspirate before injection; in- ject the dose SUBCUT; when giving the load- ing dose of two 120-mg doses, the second dose should be injected at a different site
PDF page 358
Assess: • Monitor HbA1c, lipids, B/P prior to initiation and 3-6 mo after • QT prolongation: more common in those taking class IA/III antidysrhyth- mics, heart failure, congenital long QT syndrome; monitor cardiac status at baseline and often thereafter, include ECG periodically • Anaphylaxis, angioedema (rash, trou- ble breathing): discontinue treatment and do not restart in serious reactions; assess for rash, dyspnea, wheezing, facial swelling • Liver function studies, PSA, GGT that may be elevated; bone density that may be decreased; electrolytes; if PSA is ele- vated, monitor testosterone levels
PDF page 359
Evaluate: • Therapeutic response: decreasing spread, size of tumor
PDF page 359
CLINICAL CONSIDERATIONS
PDF page 359
Patient and caregiver information: • To notify all prescribers of cardiac disease or use of all cardiac products, irregular pulse, heartbeat • Side effects and adverse reactions that may occur • Injection technique if patient/family will be giving product (provide patient informa- tion)
PDF page 359
PHARMACOKINETICS Peak 2 days, duration 50 days, half-life 53 days
PDF page 359
• Adult (male): SUBCUT 240 mg given as two 120-mg injections (40 mg/mL concentrations); maintenance 80 mg (20 mg/mL concentration) every 28 days, starting 28 days after first dose
PDF page 358