DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more

Plenaxis (Abarelix) - Indications and Dosage



Plenaxis® is indicated for the palliative treatment of men with advanced symptomatic prostate cancer, in whom LHRH agonist therapy is not appropriate and who refuse surgical castration, and have one or more of the following: (1) risk of neurological compromise due to metastases, (2) ureteral or bladder outlet obstruction due to local encroachment or metastatic disease, or (3) severe bone pain from skeletal metastases persisting on narcotic analgesia.


For safety reasons, Plenaxis® is approved with marketing restrictions. Only physicians who attest to the following qualifications and accept the following responsibilities, and on that basis enroll in PRAECIS PHARMACEUTICALS INCORPORATED's Plenaxis® PLUS Program should prescribe Plenaxis®. PRAECIS PHARMACEUTICALS INCORPORATED and its agents will provide Plenaxis® to physicians enrolled in the Plenaxis® PLUS Program.

To enroll, physicians must attest that they are able and willing to:

  • diagnose and manage advanced symptomatic prostate cancer.
  • diagnose and treat allergic reactions, including anaphylaxis.
  • have access to medication and equipment necessary to treat allergic reactions, including anaphylaxis.
  • have patients observed for development of allergic reactions for 30 minutes following each administration of Plenaxis®.
  • understand the risks and benefits of palliative treatment with Plenaxis®, including information from the Package Insert, Patient Information, and the Physician Attestation.
  • educate the patients on the risks and benefits of treatment with Plenaxis® and obtain the patient's signature on the Patient Information signature page, sign it, and place the original signed form in the patient's medical record, and give a copy of the Patient Information leaflet with the signed page to the patient.
  • report serious adverse events, such as any immediate-onset systemic allergic event (including anaphylaxis, hypotension, and syncope) as soon as possible to PRAECIS PHARMACEUTICALS INCORPORATED at 1-866-PLENAXIS (1-866-753-6294) or to the Food and Drug Administration's MedWatch Program at 1-800-FDA-1088.
  • understand that they may withdraw their enrollment in the Plenaxis® Prescribing Program by a written statement submitted to PRAECIS PHARMACEUTICALS INCORPORATED (contact information below) or that PRAECIS PHARMACEUTICALS INCORPORATED may withdraw physicians from the Plenaxis® PLUS Program if they do not meet the agreed upon responsibilities.

To enroll in the Plenaxis® Prescribing Program call 1-866-PLENAXIS (1-866-753-6294) or visit www.plenaxisplus.com.

Dose: The recommended dose of Plenaxis® is 100 mg administered intramuscularly to the buttock on Day 1, 15, 29 (week 4) and every 4 weeks thereafter. Treatment failure can be detected by measuring serum testosterone concentrations just prior to Plenaxis® administration, beginning on Day 29 and every 8 weeks thereafter.


Read the instructions completely before performing reconstitution.

The sterile powder for suspension is to be reconstituted in accordance with the following directions:


Use aseptic technique throughout.

Prior to reconstitution, gently shake the vial of Plenaxis® (abarelix for injectable suspension). Hold the vial at an angle (45 degrees) and tap lightly on table to break up any caking.

Withdraw 2.2 mL of 0.9% Sodium Chloride Inj., USP using the enclosed 18 G × 1 " needle and a 3 cc syringe. Discard the remaining diluent.

(Picture 1)

Keeping the vial upright, insert the needle all the way into the vial and inject the diluent quickly.

Before withdrawing the needle, remove 2.2 mL of air. Shake immediately.

(Picture 2)

Shake for approximately 15 seconds. Allow the vial to stand for approximately 2 minutes. Tap the vial to reduce foaming and swirl the vial occasionally.

Again, shake for approximately 15 seconds. Allow the vial to stand for approximately 2 minutes. Tap the vial to reduce foaming and swirl the vial occasionally.

(Picture 3)

Do not reinject the air into the vial. Locate a second injection spot on the stopper, and then insert the 18 G needle. Invert the vial and draw up some of the suspension into the syringe and without removing the needle from the vial reinject it at any remaining solids in the vial. Repeat the process until all solids are dispersed.

Swirl the vial before withdrawal and withdraw the entire contents (at least 2 mL) by positioning the needle at a 45 degree angle as shown in the picture.

(Picture 4)

Pull the plunger back to recover the residual suspension in the 18 G × 1 " needle.

Exchange the 18 G × 1 " needle with the enclosed 22 G × 1 " Safety Glide™ injection needle.

(Picture 5)

Insert the needle at the desired injection site, pull the plunger back to check for back-flow of blood. If blood flows into the syringe, do not inject at this site. Select another injection site.

Deliver the entire reconstituted suspension intramuscularly immediately.

(Picture 6)

Observe the patient for after injection for 30 minutes for any sign of an allergic-type response.

Plenaxis® does not contain a preservative and should be administered within 1 hour following reconstitution.


Store at 25C (77F), excursions permitted to 15-30C (59-86F), USP Controlled Room Temperature.


The physician must attest to meeting the qualifications and accepting the responsibilities in the DOSAGE AND ADMINISTRATION section of this package insert by submitting the Physician's Attestation form to PRAECIS PHARMACEUTICALS INCORPORATED to be enrolled in the Plenaxis® PLUS Program. PRAECIS PHARMACEUTICALS INCORPORATED and its agents will only provide Plenaxis® to physicians enrolled in the Plenaxis® Prescribing Program. Plenaxis® vials are not to be resold or redistributed.

Plenaxis® (abarelix for injectable suspension) is supplied as a single-dose, preservative-free vial containing 113 mg of abarelix (anhydrous free base peptide) as an abarelix CMC complex, a sterile powder (NDC 68158-149-01) which, when reconstituted with 2.2 mL of 0.9% sodium chloride solution, yields a 2 mL delivered dose of 100 mg (50 mg/mL). Each single use dispensing pack also contains: a single-use 10 mL diluent vial of 0.9% Sodium Chloride Injection, USP, one 3 cc syringe with an 18 gauge 11/2 inch needle and one 22 gauge 1 ½ inch Safety Glide™ injection needle.



830 Winter Street

Waltham, MA 02451

1-877-PRAECIS (1-877-772-3247)


Plenaxis is a registered trademark of PRAECIS PHARMACEUTICALS INCORPORATED. All rights reserved.

Issue Date: August 2004 02-01

-- advertisement -- The American Red Cross
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2017