degarelix (deg-a-rel-ix) Firmagon

 Indications

Management of advanced prostate cancer.

Action

Reversibly brings to GnRH receptors in the pituitary

gland, causing a decrease in the release of gonadotropins

and testosterone. Therapeutic Effects: Decreased

spread of prostate cancer.

Pharmacokinetics

Absorption: Well absorbed from depot following

water.

Distribution: .

Metabolism and Excretion: 70–80% undergoes

hepatic metabolism and biliary excretion, most metabolites

excreted in feces; 20–30% excreted unchanged in

urine.

Half-life: 53 days.

TIME/ACTION PROFILE (decrease in

testosterone levels)

ROUTE ONSET PEAK DURATION

SC within 1 wk 2 wk 1 mo

Contraindications/Precautions

Contraindicated in: Previous hypersensitivity; OB:

Pregnancy (may cause fetal harm) or child-bearing

women; Lactation: Not recommended for use in

women.

Use Cautiously in: Severe hepatic/renal impairment;

Previous history of cardiovascular disease including

congenital long QT syndrome, electrolyte abnormalities,

HF, concurrent use of class IA or class III

antiarrhythmics (mayqthe risk of QT prolongation);

Geri: May be more sensitive to drug effects; Pedi: Safety

and effectiveness not established.

Adverse Reactions/Side Effects

CNS: dizziness, headache, insomnia, weakness. CV:

QT INTERVAL PROLONGATION. GI:qliver enzymes, diarrhea,

nausea. GU: erectile dysfunction, testicular atrophy.

Endo: gynecomastia, pituitary gonadal suppression.

Local: injection site reactions.Metab: hot

flashes, weight gain,pbone density. Misc: hypersensitivity

reactions including ANAPHYLAXIS, ANGIOEDEMA, AND

URTICARIA, fever, sweating.

Interactions

Drug-Drug: Concurrent use with class IA antiarrhythmics,

including procainamide and quinidine

or class III antiarrhythmics including amiodarone

or sotalol mayqrisk of QT prolongation and serious

arrhythmias.

Route/Dosage

Subcut (Adults): 240 mg initially (given as two injections

of 120 mg each), followed by maintenance dose

of 80 mg every 28 days.

Availability

Powder for subcutaneous injection (requires reconstitution):

80 mg/vial, 120 mg/vial.