Product Introduction:
Prostiga 250mg is a potent anti-cancer hormonal therapy used in the treatment of metastatic castration-resistant prostate cancer (mCRPC) and metastatic high-risk castration-sensitive prostate cancer (mCSPC). It is typically administered in combination with prednisone to counteract mineralocorticoid excess caused by CYP17 inhibition.
Uses (Indications):
Prostiga (Abiraterone Acetate) is prescribed for:
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Metastatic castration-resistant prostate cancer (mCRPC)
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Metastatic castration-sensitive prostate cancer (mCSPC)
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Patients progressing after failure of docetaxel chemotherapy
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Hormone-sensitive prostate cancer with high tumor burden
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Used with prednisone to reduce side effects of mineralocorticoid excess
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Off-label: In combination regimens in clinical trials or early-stage high-risk prostate cancers
Storage Instructions:
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Store at room temperature between 20–25°C
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Protect from moisture, light, and heat
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Keep the medication in its original packaging
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Do not refrigerate or freeze
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Keep out of reach of children
How It Works (Mechanism of Action):
Abiraterone Acetate is a selective and irreversible inhibitor of the enzyme CYP17A1 (17α-hydroxylase/C17,20-lyase), which is crucial in androgen biosynthesis in the testes, adrenal glands, and prostate tumor tissue.
By inhibiting this enzyme, Abiraterone:
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Reduces the synthesis of testosterone and other androgens
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Starves prostate cancer cells of androgens, slowing or stopping their growth
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Has a more profound anti-androgen effect than first-generation agents (e.g., bicalutamide)
Because the drug also reduces cortisol production, prednisone is co-administered to prevent adrenal insufficiency and control mineralocorticoid-related side effects (like hypertension, hypokalemia, and fluid retention).
Side Effects:
Common Side Effects:
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Fatigue
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Joint swelling or discomfort (arthralgia)
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Hypertension (high blood pressure)
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Fluid retention / edema
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Hot flushes
Severe or Less Common Side Effects:
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Hypokalemia – low potassium levels requiring monitoring
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Liver enzyme elevation (hepatotoxicity)
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Adrenal insufficiency if not taken with prednisone
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Cardiac arrhythmias
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Urinary tract infections
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Bone fractures – due to androgen deprivation
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Rare: Sepsis, myopathy, increased fracture risk
Dosage (Typical Recommended Dose):
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Standard adult dose: 1,000 mg (i.e., four 250mg tablets) once daily
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To be taken on an empty stomach – at least 1 hour before or 2 hours after food
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Prednisone 5mg twice daily is co-administered
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Dose adjustments may be required in cases of hepatic impairment
Method of Administration:
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Administer orally with water, whole—do not crush or chew
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Take in the morning, at the same time daily
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Must be taken on an empty stomach to avoid increased absorption and toxicity
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Ensure concurrent prednisone therapy to prevent side effects
Precautions:
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Monitor for liver function abnormalities (AST, ALT, bilirubin)
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Monitor blood pressure, serum potassium, and fluid retention
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Use with extreme caution in patients with heart failure or history of arrhythmias
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Not indicated for use in women or pediatric patients
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Men should use effective contraception during and for 3 months after therapy
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Risk of bone loss—consider bone-modifying agents in long-term therapy
Drug Interactions:
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CYP3A4 inducers (e.g., rifampin) – may reduce Abiraterone effectiveness
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CYP2D6 substrates (e.g., metoprolol, desipramine) – increased levels possible
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CYP2C8 inhibitors – can increase drug concentration and toxicity
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Spironolactone – avoid due to its androgenic activity
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Co-administration with glucocorticoids (prednisone) is mandatory
Allergies (Warnings for Allergic Reactions):
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Rare allergic reactions such as rash, itching, or hives
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Discontinue immediately in case of angioedema, breathing difficulties, or anaphylaxis
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Not recommended in patients with known hypersensitivity to Abiraterone or excipients
Overdose Information:
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Symptoms may include fluid retention, hypokalemia, hypertension, or cardiac effects
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No specific antidote – provide supportive treatment
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Monitor vital signs, liver function, electrolytes, and perform ECG
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Seek emergency medical attention immediately in case of overdose
Missed Dose Instructions:
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If a dose is missed, take it as soon as remembered on the same day
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If missed entirely for a day, do not double dose the next day
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Continue regular dosing from the next scheduled dose
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Ensure prednisone is also taken as prescribed
Additional Notes:
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Abiraterone is a cornerstone treatment for late-stage prostate cancer
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Requires long-term hormone suppression and monitoring
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Regular PSA tests, imaging, and liver panels are needed during therapy
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Combining with GnRH agonists/antagonists may be necessary unless surgically castrated
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Alcohol and high-fat meals should be avoided to prevent adverse absorption changes
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Patients should carry steroid medication info (prednisone) at all times
