Prescribing Flotera (Flutamide)
Flutamide is indicated exclusively for metastatic prostate cancer in combination with LHRH agonist therapy as part of total androgen blockade, and should never be used as monotherapy or in any other clinical context. 1
Approved Indication
Flutamide is FDA-approved only for the treatment of metastatic prostate cancer when used in combination with an LHRH (luteinizing hormone-releasing hormone) agonist injection. 1 This combination therapy is called "total androgen blockade," where the LHRH agonist reduces androgen levels systemically while flutamide blocks the effect of remaining androgens on tumor cells. 1
Absolute Contraindications
Flutamide must never be prescribed in the following situations:
- Patients with pre-existing liver disease or hepatic dysfunction 1
- Patients with baseline ALT values exceeding twice the upper limit of normal 1
- Women (flutamide is for use only in men) 1
- Patients with known hypersensitivity to flutamide 1
Critical Safety Monitoring Requirements
Mandatory Hepatic Monitoring Protocol
Before initiating flutamide, you must establish a rigorous monitoring schedule due to the risk of potentially fatal hepatic injury: 1
- Baseline: Measure serum transaminase levels before starting treatment 1
- First 4 months: Monthly serum transaminase measurements 1
- After 4 months: Periodic monitoring at regular intervals 1
- At any time: Immediate liver function testing if patient develops suggestive symptoms 1
Warning Signs Requiring Immediate Discontinuation
Instruct patients to contact you immediately if they develop any of these symptoms, as they may indicate hepatic injury: 1
- Loss of appetite 1
- Nausea and vomiting 1
- Abdominal pain 1
- Fatigue or flu-like symptoms (muscle aches, soreness) 1
- Brown/dark urine 1
- Jaundice (yellowing of skin or eyes) 1
If jaundice develops or ALT rises above 2 times the upper limit of normal, immediately discontinue flutamide and closely monitor liver function tests until resolution. 1
Clinical Context and Timing
Approximately half of reported cases of hepatic injury occurred within the first 3 months of treatment, though liver failure can occur at any time during therapy. 1 Postmarketing reports have documented hospitalizations and rare deaths due to acute hepatic failure in patients taking flutamide. 1 The hepatic injury was reversible after discontinuation in some patients, emphasizing the importance of early detection through vigilant monitoring. 1
Common Pitfall to Avoid
Never use flutamide as monotherapy for prostate cancer. It must always be combined with an LHRH agonist to achieve total androgen blockade. 1 The drug works by blocking androgen receptors on tumor cells, but without concurrent suppression of androgen production via LHRH agonist therapy, the treatment will be ineffective. 1
Patient Counseling Points
Advise patients to: 1
- Take flutamide exactly as prescribed in combination with their LHRH agonist injections
- Maintain adequate hydration
- Report any of the warning signs listed above immediately
- Attend all scheduled laboratory monitoring appointments
- Understand that this is a long-term treatment requiring ongoing surveillance