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Xtandi Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

Xtandi (enzalutamide) is indicated for the treatment of prostate cancer in patients who have previously received Docefrez (docetaxel). Possible side effects of Xtandi are seizure, weakness, back pain, diarrhea, joint pain, hot flashes, headache, and muscle weakness.

Xtandi is available in capsules of 40 mg. The recommended dosage of Xtandi is 160 mg (four 40 mg capsules) administered orally once daily. Swallow capsules whole. Xtandi can be taken with or without food. Xtandi may interact with other drugs. Tell your doctor all prescription and OTC medications you are taking. Xtandi is not indicated for use in women and may cause fetal harm when administered to a pregnant woman. Consult your doctor before breastfeeding.

Xtandi (enzalutamide) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is Prescribing information?

The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.

Xtandi FDA Prescribing Information: Side Effects
(Adverse Reactions)


The following is discussed in more detail in other sections of the labeling:

Clinical Trial Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

In the randomized clinical trial in patients with metastatic castration-resistant prostate cancer who had previously received docetaxel, patients received XTANDI 160 mg orally once daily (N = 800) or placebo (N = 399). The median duration of treatment was 8.3 months with XTANDI and 3.0 months with placebo. All patients continued androgen deprivation therapy. Patients were allowed, but not required, to take glucocorticoids. During the trial, 48% of patients on the XTANDI arm and 46% of patients on the placebo arm received glucocorticoids. All adverse events and laboratory abnormalities were graded using NCI CTCAE version 4.

The most common adverse drug reactions ( ≥ 5%) reported in patients receiving XTANDI in the randomized clinical trial were asthenia/fatigue, back pain, diarrhea, arthralgia, hot flush, peripheral edema, musculoskeletal pain, headache, upper respiratory infection, muscular weakness, dizziness, insomnia, lower respiratory infection, spinal cord compression and cauda equina syndrome, hematuria, paresthesia, anxiety, and hypertension. Grade 3 and higher adverse reactions were reported among 47% of XTANDI-treated patients and 53% of placebo-treated patients. Discontinuations due to adverse events were reported for 16% of XTANDI-treated patients and 18% of placebo-treated patients. The most common adverse reaction leading to treatment discontinuation was seizure, which occurred in 0.9% of the XTANDI-treated patients compared to none (0%) of the placebo-treated patients. Table 1 shows adverse reactions reported in the randomized clinical trial that occurred at a ≥ 2% absolute increase in frequency in the XTANDI arm compared to the placebo arm.

Table 1: Adverse Reactions in the Randomized Trial

N = 800
N = 399
Grade 1-4
Grade 3-4
Grade 1-4
Grade 3-4
General Disorders
  Asthenic Conditionsa 50.6 9 44.4 9.3
  Peripheral Edema 15.4 1 13.3 0.8
Musculoskeletal And Connective Tissue Disorders
  Back Pain 26.4 5.3 24.3 4
  Arthralgia 20.5 2.5 17.3 1.8
  Musculoskeletal Pain 15 1.3 11.5 0.3
  Muscular Weakness 9.8 1.5 6.8 1.8
  Musculoskeletal Stiffness 2.6 0.3 0.3 0
Gastrointestinal Disorders
  Diarrhea 21.8 1.1 17.5 0.3
Vascular Disorders
  Hot Flush 20.3 0 10.3 0
  Hypertension 6.4 2.1 2.8 1.3
Nervous System Disorders
  Headache 12.1 0.9 5.5 0
  Dizzinessb 9.5 0.5 7.5 0.5
  Spinal Cord Compression and Cauda Equina Syndrome 7.4 6.6 4.5 3.8
  Paresthesia 6.6 0 4.5 0
  Mental Impairment Disordersc 4.3 0.3 1.8 0
  Hypoesthesia 4 0.3 1.8 0
Infections And Infestations
  Upper Respiratory Tract Infectiond 10.9 0 6.5 0.3
  Lower Respiratory Tract And Lung Infectione 8.5 2.4 4.8 1.3
Psychiatric Disorders
  Insomnia 8.8 0 6 0.5
  Anxiety 6.5 0.3 4 0
Renal And Urinary Disorders
  Hematuria 6.9 1.8 4.5 1
  Pollakiuria 4.8 0 2.5 0
Injury, Poisoning And Procedural Complications
  Fall 4.6 0.3 1.3 0
  Non-pathologic Fractures 4 1.4 0.8 0.3
Skin And Subcutaneous Tissue Disorders
  Pruritus 3.8 0 1.3 0
  Dry Skin 3.5 0 1.3 0
Respiratory Disorders
  Epistaxis 3.3 0.1 1.3 0.3
a Includes asthenia and fatigue.
b Includes dizziness and vertigo.
c Includes amnesia, memory impairment, cognitive disorder, and disturbance in attention.
d Includes nasopharyngitis, upper respiratory tract infection, sinusitis, rhinitis, pharyngitis, and laryngitis.
e Includes pneumonia, lower respiratory tract infection, bronchitis, and lung infection.

Laboratory Abnormalities

In the randomized clinical trial, Grade 1-4 neutropenia occurred in 15% of patients on XTANDI (1% Grade 3-4) and in 6% of patients on placebo (no Grade 3-4). The incidence of Grade 1-4 thrombocytopenia was similar in both arms; 0.5% of patients on XTANDI and 1% on placebo experienced Grade 3-4 thrombocytopenia. Grade 1-4 elevations in ALT occurred in 10% of patients on XTANDI (0.3% Grade 3-4) and 18% of patients on placebo (0.5% Grade 3-4). Grade 1-4 elevations in bilirubin occurred in 3% of patients on XTANDI and 2% of patients on placebo.


In the randomized clinical trial, 1.0% of patients treated with XTANDI compared to 0.3% of patients on placebo died from infections or sepsis. Infection-related serious adverse events were reported in approximately 6% of the patients on both treatment arms.

Falls and Fall-related Injuries

In the randomized clinical trial, falls or injuries related to falls occurred in 4.6% of patients treated with XTANDI compared to 1.3% of patients on placebo. Falls were not associated with loss of consciousness or seizure. Fall-related injuries were more severe in patients treated with XTANDI and included non-pathologic fractures, joint injuries, and hematomas.


In the randomized clinical trial, 1.6% of patients treated with XTANDI were reported to have Grade 1 or 2 hallucinations compared to 0.3% of patients on placebo. Of the patients with hallucinations, the majority were on opioid-containing medications at the time of the event. Hallucinations were visual, tactile, or undefined.

Read the entire FDA prescribing information for Xtandi (Enzalutamide Capsules) »


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