Flutamide

In animal studies, flutamide demonstrates potent antiandrogenic effects. It exerts its antiandrogenic action by inhibiting androgen uptake and/or by inhibiting nuclear binding of androgen in target tissues or both. Prostatic carcinoma is known to be androgen-sensitive and responds to treatment that counteracts the effect of androgen and/or removes the source of androgen, e.g. castration.

The recommended dosage of Flutamide in combination with orchiectomy or in combination with an LHRH agonist is one 250 mg tablet three times a day at eight-hour intervals. In combination with an LHRH agonist, either the two agents may be initiated simultaneously, or Flutamide tablet therapy may be started 24 hours prior to initiation of the LHRH agonist. In the management of bulky locally advanced Stage B 2 and Stage C prostatic carcinoma, the recommended dosage is one 250 mg tablet, three times a day at eight-hour intervals. Flutamide should be started simultaneously or 24 hours prior to initiation of the LHRH agonist. Administration of Flutamide should begin eight weeks prior to external beam radiation therapy and continue through the course of radiation therapy.

Interactions between Flutamide Tablets and leuprolide have not occurred. In patients receiving long-term oral-anticoagulant therapy, increases in prothrombin time have been reported after flutamide monotherapy was initiated. Therefore close monitoring of prothrombin time is recommended and adjustment of the anticoagulant dose may be necessary when flutamide tablets are administered concomitantly. Cases of increased theophylline plasma concentrations have been reported in patients receiving concomitant theophylline and flutamide tablets. Theophylline is primarily metabolized by CYP1A2, which is the primary enzyme responsible for the conversion of flutamide to its active agent 2-hydroxyflutamide.

Flutamide tablets are contraindicated in patients who have shown hypersensitivity to flutamide or any component of this preparation. Flutamide is contraindicated in patients with severe hepatic impairment. Flutamide has not been studied in women and is not indicated for this population, particularly for nonserious or non-threatening conditions.

Cardiovascular System: hypertension in 1% of patients. Rarely thrombophlebitis, pulmonary embolism, myocardial infarction.

Central Nervous System: CNS (drowsiness/confusion/depression/anxiety/nervousness) reactions occurred in 1% of patients. Rarely insomnia, tiredness, headache, dizziness, weakness, malaise, blurred vision and decreased libido have been reported.

Endocrine System: gynecomastia in 9% of patients. Rarely breast tenderness sometimes accompanied by galactorrhoea.

Gastrointestinal System: nausea/vomiting occurred in 11%; diarrhea 12%, anorexia 4%, and other gastrointestinal disorders occurred in 6% of patients. Increased appetite, indigestion and constipation have also been reported.

Hematopoietic System: anaemia occurred in 6% of patients, leukopenia 3%, thrombocytopenia 1%.

Liver and Biliary System: clinically evident hepatitis and jaundice occurred in <1% of patients.

Skin: irritation at the injection site and rash occurred in 3% of patients. Photosensitivity reactions have been reported in five patients.

No studies have been conducted in pregnant or lactating women. Therefore, the possibility that Flutamide may cause fetal harm if administered to a pregnant woman, or may be present in the breast milk of lactating women must be considered.

Periodic liver function tests and sperm count determinations must be performed in patients on long-term treatment with flutamide. After long-term administration in rats, flutamide produced testicular interstitial cell adenomas and dose-related increases in mammary gland adenomas or carcinomas. The relevance of these findings to humans is unknown. It should be noted that few cases of malignant breast neoplasms have been reported in male patients receiving flutamide; causality has not been established. Since flutamide tends to elevate plasma testosterone and estradiol levels, fluid retention may occur. Accordingly, flutamide should be used with caution in those patients with cardiac disease.

Hepatic Injury: Treatment with flutamide should not be initiated in patients with serum transaminase levels exceeding 2 to 3 times the upper limit of normal. Since transaminase abnormalities, cholestatic jaundice, hepatic necrosis and hepatic encephalopathy have been reported with the use of flutamide, periodic liver function tests must be performed in all patients. Appropriate laboratory testing should be done monthly for the first 4 months, and periodically thereafter and at the first symptom/sign of liver dysfunction (e.g., pruritus, dark urine, persistent anorexia, jaundice, right upper quadrant tenderness or unexplained "flu-like" symptoms). If the patient has laboratory evidence of liver injury or jaundice, in the absence of biopsy-confirmed liver metastases, flutamide therapy should be discontinued if the patient develops jaundice or if serum transaminase levels rise to 2 to 3 times the upper limit of normal, even in clinically asymptomatic patients. The hepatic injury is usually reversible after discontinuation of therapy and in some patients, after dosage reduction. However, there have been reports of death following severe hepatic injury associated with the use of flutamide.

Hormonal Chemotherapy

Keep below 30°C temperature, away from light & moisture. Keep out of the reach of children.