"The U.S. Food and Drug Administration today approved Xofigo (radium Ra 223 dichloride) to treat men with symptomatic late-stage (metastatic) castration-resistant prostate cancer that has spread to bones but not to other organs. It is intended for"...
(Generic versions may still be available.)
Plenaxis Side Effects Center
Medical Editor: John P. Cunha, DO, FACOEP
Plenaxis (abarelix) for Injectable Suspension inhibits gonadotropin releasing-hormone (GnRH) and is used in the palliative treatment of advanced prostate cancer. The brand name of this medication is discontinued, but generic versions may be available. Common side effects include hot flashes, sleep disturbances, breast enlargement or pain, diarrhea or constipation, swelling, nausea, dizziness, headache, fatigue, or changes with or difficulty urinating.
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. Plenaxis may interact with other drugs. Tell your doctor all medications and supplements you use. Plenaxis causes birth defects. Do not use this medication if you are pregnant or if you could become pregnant during treatment. This drug is not intended for use by women, therefore it is unlikely to be used while pregnant or breastfeeding; consult your doctor if you have questions.
Our Plenaxis (abarelix) for Injectable Suspension Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What is Patient Information in Detail?
Easy-to-read and understand detailed drug information and pill images for the patient or caregiver from Cerner Multum.
Plenaxis in Detail - Patient Information: Side Effects
In some cases, the use of abarelix has resulted in serious allergic reactions. An allergic reaction may occur after any injection of the medication, including, but not limited to the first dose. Patients should be observed in the doctor's office for at least 30 minutes following each dose so that immediate treatment of an allergic reaction can be obtained if needed.
Other, less serious side effects may be more likely to occur. Talk to your doctor if you experience
- hot flashes;
- sleep disturbances;
- breast enlargement or pain;
- diarrhea or constipation;
- fatigue; or
- changes with or difficulty urinating.
Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.
Read the entire detailed patient monograph for Plenaxis (Abarelix) »
What is Prescribing information?
The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.
Plenaxis FDA Prescribing Information: Side Effects
In the single study of Plenaxis™ conducted in men with advanced symptomatic prostate cancer, adverse events reported by ≥ 10% of patients are listed in Table 4. Adverse events are listed without regard to causality. Causality is often difficult to assess in elderly patients with multiple co-morbidities and prostate cancer.
Table 4: Adverse Events in ≥ 10% of Patients in the Advanced
Symptomatic Prostate Cancer Study (without regard for causality).
|Hot flushes*||64 (79)|
|Sleep disturbance*||36 (44)|
|Breast enlargement*||24 (30)|
|Breast pain/nipple tenderness*||16 (20)|
|Back pain||14 (17)|
|Peripheral edema||12 (15)|
|Upper respiratory tract infection||10 (12)|
|Micturition frequency||8 (10)|
|Urinary retention||8 (10)|
|Urinary tract infection||8 (10)|
|* Pharmacological consequence of androgen deprivation|
Changes in Laboratory Values
Clinically meaningful increases in serum transaminases were seen in a small percentage of patients in both treatment groups in each active-controlled Plenaxis™ study. In Study 1 and Study 2 combined, the percentage of Plenaxis™ patients reporting serum ALT > 2.5 times upper limit of normal or > 200 U./L was 8.2% and 1.8%, respectively. The percentage reporting serum AST > 2.5 times upper limit of normal or > 200 U/L was 3.1% and 0.8%, respectively. Similar results were reported for active comparators.
Slight decrease in hemoglobin, a pharmacological consequence of castration, were observed in patients receiving Plenaxis™ and active comparator. Mean increases in serum triglycerides of approximately 10% were seen in Plenaxis™ -treated patients.
Read the entire FDA prescribing information for Plenaxis (Abarelix) »
Additional Plenaxis Information
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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