Proscan250 mg

Proscan is a nonsteroidal antiandrogen indicated for the following use:

Established / FDA-approved use

• Metastatic (Stage D2) prostate cancer — Proscan is indicated in combination with a luteinizing hormone-releasing hormone (LHRH) agonist (e.g., leuprolide, goserelin) for combined (total) androgen blockade in men with metastatic carcinoma of the prostate, either as initial therapy or in patients who have already been medically or surgically castrated.

Off-label use (not FDA-approved)

• Proscan has historically been used off-label, at lower doses, for hirsutism in women with polycystic ovary syndrome (PCOS); this use is not approved, is not recommended by MedEasy, and carries a meaningful risk of serious liver injury — it should only be considered under direct specialist supervision where safer alternatives are unsuitable.

Proscan is not indicated for use in women or children as part of routine care; see Use in Special Populations.

Each capsule/tablet contains Flutamide INN 250 mg.

Proscan is a synthetic, nonsteroidal antiandrogen that works by blocking the action of androgens (male sex hormones such as testosterone and dihydrotestosterone) at the androgen receptor. It does not suppress hormone production itself, so it is used together with a GnRH/LHRH agonist, which lowers testosterone production, to achieve a more complete ("combined" or "total") blockade of androgen activity. Proscan is used mainly in men with advanced (metastatic) prostate cancer, a disease that is stimulated to grow by androgens.

Antiandrogen (nonsteroidal androgen receptor antagonist); hormonal antineoplastic agent.

Flutamide and its principal active metabolite, 2-hydroxyflutamide, competitively bind to the androgen receptor in target tissues (including the prostate and prostate cancer cells), blocking the uptake and/or nuclear binding of androgens. This prevents androgen-stimulated growth of prostatic tumor tissue without lowering serum testosterone itself. Because circulating androgens (and the transient testosterone surge that occurs when an LHRH agonist is first started) can still stimulate tumor growth through unblocked pathways, Flutamide is combined with an LHRH agonist to prevent this "flare" and to achieve combined androgen blockade. Flutamide is well absorbed orally, extensively metabolized in the liver (partly via CYP1A2) to 2-hydroxyflutamide, and eliminated mainly in urine; the elimination half-life of 2-hydroxyflutamide is approximately 6–8 hours and increases somewhat with age.

Proscan capsules/tablets may be taken with or without food. Swallow whole with a glass of water; do not crush or chew unless the specific product labeling allows it. Take doses at evenly spaced intervals (approximately every 8 hours) to maintain steady drug levels, and do not stop treatment or skip doses without medical advice, since Proscan is part of a combined hormonal therapy regimen for cancer.

Proscan has the following clinically significant interactions:

• Warfarin and other coumarin anticoagulants: Proscan can potentiate anticoagulant effect and raise INR/prothrombin time; more frequent coagulation monitoring and anticoagulant dose adjustment may be required.
• Other hepatotoxic drugs/alcohol: concurrent use with other medicines known to affect the liver may add to the hepatotoxic risk of Proscan; liver function should be monitored more closely.
• Theophylline: reduced clearance of theophylline has been reported with Proscan, which may raise theophylline levels; monitoring is advised where co-administered.

Common side effects of Proscan include:

• Gynecomastia and breast tenderness/enlargement (common in men)
• Hot flashes
• Decreased libido and, less commonly, erectile difficulty
• Diarrhea, nausea, or loss of appetite
• Yellow-green discoloration of urine (harmless)

Serious but less common effects requiring prompt medical attention include hepatotoxicity (see Precautions and Warnings) and methemoglobinemia (rare; symptoms include bluish skin/lips, shortness of breath, fatigue).

Proscan is not indicated for use in women. It has not been established as safe for use during pregnancy or breastfeeding, and animal studies with related antiandrogens have shown adverse reproductive/developmental effects. If accidental exposure or off-label use in a woman who is or may become pregnant is being considered, Proscan should be used only if clearly needed and only under direct specialist supervision, after the potential risks to the fetus/infant have been fully discussed with a physician. It is not known whether Proscan passes into breast milk; breastfeeding is not recommended during treatment.

Hepatotoxicity: Rare but potentially serious, and in some cases fatal, liver injury (including hepatitis and liver failure) has been reported with Proscan. Liver function tests should be checked before starting treatment, monitored regularly (e.g., monthly for the first several months) and periodically thereafter, and whenever symptoms suggestive of liver problems occur (e.g., jaundice, dark urine, persistent nausea, right upper abdominal pain, unusual fatigue). Proscan should be discontinued promptly if significant liver injury is confirmed.

Not for use in women or children: Proscan is approved only for adult men with prostate cancer; safety and efficacy have not been established in women or pediatric patients (see Use in Special Populations).

Gynecomastia: common; usually not a reason to stop treatment but should be discussed with the physician if bothersome.

Methemoglobinemia: a rare blood disorder has been reported; seek medical attention for unexplained shortness of breath, fatigue, or bluish discoloration of the skin/lips.

Photosensitivity: some patients may become more sensitive to sunlight; sun protection is advisable.

Proscan should be used exactly as prescribed, and any tumor flare symptoms (e.g., new or worsening bone pain, urinary obstruction) at the start of combined therapy should be reported to the physician promptly.

There is no specific antidote for Proscan overdose. Manifestations that might be expected include increased signs of antiandrogen activity (e.g., gynecomastia) and potentially increased risk of hepatotoxicity or methemoglobinemia. If an overdose of Proscan is suspected, seek immediate medical attention or contact a poison control center; treatment is supportive, with monitoring of liver function and general clinical status. Do not attempt to manage a suspected overdose at home without medical guidance.

Store at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

Women: Proscan is not indicated for routine use in women; see Pregnancy and Lactation.

Children: Safety and efficacy of Proscan have not been established in pediatric patients; it is not indicated for use in children (see Pediatric Uses).

Elderly: Proscan is used in older men with prostate cancer (the typical patient population); no specific dose reduction is established, but the elimination half-life of the active metabolite tends to be longer with advancing age, so patients should be monitored for adverse effects, particularly hepatotoxicity.

Hepatic impairment: Contraindicated in severe hepatic impairment; use with caution and close liver monitoring in mild-to-moderate hepatic impairment.

Renal impairment: No well-established dose adjustment; use with appropriate clinical monitoring.

For metastatic prostate cancer, Proscan is typically continued long-term, together with the LHRH agonist, for as long as the treating physician determines there is clinical benefit and no unacceptable toxicity. Treatment should not be stopped or interrupted without medical advice, as doing so may allow the cancer to progress.

Nonsteroidal antiandrogens; androgen receptor antagonists; hormonal antineoplastic agents.

Flutamide and its active metabolite 2-hydroxyflutamide act as competitive antagonists at the androgen receptor, blocking binding and nuclear uptake of androgens in target tissues such as the prostate. This inhibits androgen-driven stimulation of prostate cancer cell growth. Because Flutamide does not reduce androgen production itself, it is combined with an LHRH agonist (which suppresses testicular testosterone synthesis) to achieve a more complete androgen blockade.

Safety and efficacy of Proscan have not been established in children, and it is not indicated for pediatric use. Proscan should not be given to children outside of a specialist/investigational setting.