Usual Adult Dose for Prostate Cancer

100 mg administered intramuscularly to the buttock on day 1, 15, 29 (week 4) and every 4 weeks thereafter.

Renal Dose Adjustments

Data not available.

Liver Dose Adjustments

Data not available.

Precautions

Because abarelix may prolong the QT interval, physicians should carefully consider whether the risks of abarelix outweigh the benefits in patients with baseline QTc values >450 msec and in patients taking class IA or class III antiarrhythmic medications.

Clinically meaningful transaminase elevation have been reported in patients receiving abarelix. Therefore, serum transaminase levels should be obtained before and during treatment with abarelix.

Extended treatment with abarelix may result in a decrease in bone mineral density.

Dialysis

Data not available.

Other Comments

Abarelix is available as a depot suspension for intramuscular injection.

Treatment failure can be detected by measuring serum total testosterone concentrations just prior to administration on day 29 and then every eight weeks.

The brand name for abarelix is Plenaxis. Only physicians who have enrolled in the Plenaxis PLUS program (Plenaxis user safety program) may prescribe Plenaxis.

Effectiveness to suppress serum testosterone to castrate levels decreases with continued dosing in some patients. Effectiveness beyond twelve months has not been established. The decrease in overall effectiveness of abarelix with increased duration of treatment is greater in patients who weigh more than 225 pounds. Strict monitoring of serum testosterone in patients weighing over 225 pounds is recommended.