Trade Names:Plenaxis- Injectable Suspension 113 mg
Directly suppresses luteinizing hormone and follicle stimulating hormone secretion, thereby reducing the secretion of testosterone by the testes.
Slowly absorbed following IM injection, reaching a peak concentration of 43.4 ng/mL approximately 3 days after injection.
Vd is about 4,040 L. AUC is about 500 ng•day/mL; 96% to 99% is protein bound.
Major metabolites are formed via hydrolysis of peptide bonds.
Approximately 13% unchanged in the urine. The t ½ is about 13.2 days.
Palliative treatment of advanced symptomatic prostate cancer in men in whom luteinizing hormone-releasing hormone agonist therapy is not appropriate and who refuse surgical castration, and have 1 or more of the following: risk of neurological compromise caused by metastases; ureteral or bladder outlet obstruction caused by local encroachment or metastatic disease; or severe bone pain from skeletal metastases persisting on narcotic analgesia.
Women; pediatric patients; pregnancy; hypersensitivity to any component of the product.
IM 100 mg to buttock on days 1, 15, 29 (week 4) and every 4 wk thereafter.
Store vials at controlled room temperature (59° to 86°F).
Because the QT interval may be prolonged by abarelix, benefits of use should outweigh risk of potential QT prolongation.
None well documented.
Sleep disturbances (44%); dizziness, headache (12%); fatigue (10%).
Constipation (15%); diarrhea (11%); nausea (10%).
Breast enlargement (30%); breast pain/nipple tenderness (20%); dysuria, micturition frequency, urinary retention, UTI (10%).
Increased serum triglycerides (10%); increased ALT (8%); increased AST (3%).
Upper respiratory tract infection (12%).
Hot flushes (79%); pain (31%); back pain (17%); peripheral edema (15%); immediate-onset systemic allergic reactions.
Immediate-onset systemic allergic reactions, some resulting in hypotension and syncope, can occur. May only be prescribed by physicians who have enrolled in the Plenaxis PLUS program.
Monitor patient for immediate-onset allergic reaction (eg, hives, itching, hypotension, syncope) for at least 30 min following each injection. Immediately inform health care provider if noted and be prepared to treat appropriately.Treatment assessment
Periodically assess and document response to treatment. Inform health care provider if any of the symptoms of advanced prostate cancer (eg, bone pain, neurological compromise, urinary symptoms) are not improving or are worsening.
Category X .
Safety and efficacy not established.
A decrease in overall effectiveness with increased duration of treatment may occur, especially in patients weighing more than 225 pounds.