What to monitor in a patient on Xtandi (enzalutamide)?

From the Guidelines

When monitoring a patient on Xtandi (enzalutamide), healthcare providers should prioritize regular assessments of PSA levels, seizure risk, falls and fractures, fatigue, hot flashes, liver function, blood pressure, cognitive impairment, and potential drug interactions, as these are the most critical factors affecting morbidity, mortality, and quality of life, as indicated by the most recent and highest quality study 1.

Key Monitoring Parameters

• PSA levels: Evaluate treatment response typically every 3 months 1
• Seizure risk: Monitor for seizures, especially in patients with predisposing factors, as enzalutamide lowers the seizure threshold 1
• Falls and fractures: Check for increased risk, particularly in elderly patients 1
• Fatigue: Evaluate for fatigue, which affects about one-third of patients 1
• Hot flashes: Monitor for hot flashes, a common side effect 1
• Liver function: Regular liver function tests are important as enzalutamide can cause hepatotoxicity 1
• Blood pressure: Monitor blood pressure since hypertension may occur 1
• Cognitive impairment: Assess for cognitive impairment, including memory issues and confusion, which can develop during treatment 1
• Drug interactions: Evaluate drug interactions as enzalutamide is a strong CYP3A4 inducer that can reduce the effectiveness of many medications 1
• Complete blood counts: Recommended to monitor for potential hematologic effects 1
• Posterior reversible encephalopathy syndrome: Assess for this rare but serious neurological condition that can occur with treatment 1

Additional Considerations

• The PROSPER trial demonstrated that enzalutamide improved metastasis-free survival in patients with nonmetastatic CRPC, with a median metastasis-free survival of 36.6 months compared to 14.7 months with placebo 1
• Adverse events, including fatigue, hypertension, major adverse cardiovascular events, and mental impairment disorders, were more common in patients receiving enzalutamide compared to placebo 1
• Patient-reported outcomes from the PROSPER trial indicated that enzalutamide delayed pain progression, symptom worsening, and decrease in functional status compared with placebo 1

From the FDA Drug Label

Seizure occurred from 13 to 2250 days after initiation of XTANDI. Monitor for signs and symptoms of ischemic heart disease. Evaluate patients for fracture and fall risk. Monitor and manage patients at risk for fractures according to established treatment guidelines and consider use of bone-targeted agents Swallow each XTANDI capsule or tablet whole with enough water to make sure that you can swallow all of the medicine successfully.

The patient on Xtandi (enzalutamide) should be monitored for:

• Seizure: risk of developing a seizure while receiving XTANDI
• Ischemic heart disease: signs and symptoms of heart problems
• Falls and fractures: risk of falls and bone fractures
• Swallowing problems: ability to swallow capsules or tablets whole with enough water These are potential serious side effects of XTANDI, and monitoring is necessary to ensure patient safety 2.

From the Research

Monitoring Patients on Xtandi (Enzalutamide)

To ensure safe and effective treatment with Xtandi (enzalutamide), several factors should be monitored in patients, including:

• Seizure risk: Patients with a history of seizure or risk factors for seizure should be closely monitored 3
• Central nervous system (CNS) events: Enzalutamide has been associated with an increased risk of CNS events, including seizure and posterior reversible encephalopathy syndrome (PRES) 4, 5
• Fatigue, diarrhea, and hot flashes: Common adverse events associated with enzalutamide treatment 6, 7
• Prostate-specific antigen (PSA) levels: Monitoring PSA levels can help assess treatment response and disease progression 6, 7
• Radiographic progression: Regular imaging studies can help monitor disease progression and treatment response 6

Laboratory and Imaging Studies

Regular laboratory and imaging studies should be performed to monitor:

• PSA levels: To assess treatment response and disease progression 6, 7
• Complete blood counts: To monitor for potential hematologic adverse events
• Liver function tests: To monitor for potential hepatic adverse events
• Imaging studies (e.g., CT scans, bone scans): To monitor disease progression and treatment response 6

Patient Education and Monitoring

Patients should be educated on the potential risks and benefits of enzalutamide treatment and monitored closely for adverse events, including:

• Seizure risk: Patients should be advised to seek medical attention immediately if they experience any symptoms of seizure 3
• CNS events: Patients should be monitored for symptoms of CNS events, including headache, confusion, and vision changes 4, 5
• Adverse events: Patients should be monitored for common adverse events, including fatigue, diarrhea, and hot flashes 6, 7