Pilot Study of Cyclobenzaprine for Treatment of Sleep Disturbance in Aromatase Inhibitor-treated Breast Cancer Patients
Condition: Sleep Initiation and Maintenance Disorders; Pain
MeSH terms: Dyssomnias; Parasomnias; Sleep Initiation and Maintenance Disorders
Intervention: Cyclobenzaprine
Intervention description: 5 milligrams orally 2 hours before bedtime
Intervention MeSH terms: Cyclobenzaprine
Phase: Phase 2
Study type: Interventional
Primary purpose: Supportive Care
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 2.0
Sex: Female
Minimum age: 18 Years
Healthy volunteers: No
Keywords: Breast cancer; Aromatase inhibitor

Summary:

      Many women with breast cancer who are treated with aromatase inhibitor medications develop
      difficulty sleeping and fatigue during treatment. Some examples of aromatase inhibitor
      medications include anastrozole (Arimidex), exemestane (Aromasin), and letrozole (Femara).
      Frequently, sleeping pills do not work very well to improve sleep. Cyclobenzaprine (Flexeril)
      is a medication that was originally developed to treat muscle spasms. It may also improve
      sleep in patients with chronic pain disorders, such as fibromyalgia. In this study we are
      testing to see if cyclobenzaprine at bedtime will help improve sleep in women treated with
      aromatase inhibitors.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Female gender, age ≥ 18, postmenopausal.

          -  Histologically proven stage 0-III invasive carcinoma of the breast

          -  Initiating or have been receiving a standard dose of aromatase inhibitor therapy
             (letrozole 2.5mg once daily or exemestane 25mg once daily or anastrozole 1mg once
             daily) for up to a total of 48 months of AI therapy.

          -  Trouble sleeping during the past week. (After signing the informed consent document,
             subjects must also have a global PSQI score of ≥5)

          -  ECOG performance status 0-2 (see Appendix A).

        Exclusion Criteria:

          -  Known hypersensitivity to cyclobenzaprine or any of the inactive ingredients

          -  Diagnosis of sleep apnea that is currently interfering with sleep or requiring CPAP,
             restless leg syndrome that is currently interfering with sleep or requiring
             medication, or Epworth sleepiness scale >10.

          -  Subjects with a history of hypothyroidism must have been on a stable dose of thyroid
             replacement medicine for at least 3 months prior to enrollment

          -  Treatment with steroids within 1 month

          -  Treatment with monoamine oxidase inhibitors (MAO-I) within 14 days of enrollment.

          -  Concurrent treatment with bupropion, MAO inhibitors, phenothiazines (including
             thioridazine), selegiline, tramadol, or medications known to prolong the QT interval
             (www.azcert.org/medical-pros/drug-lists/drug-lists.cfm)

          -  Currently primary psychiatric diagnosis (schizophrenia, psychosis) or suicidal
             ideation, history of bipolar disorder, or seizure disorder

          -  Known moderate or severe hepatic impairment

          -  History of congestive heart failure or cardiac arrhythmia (other than atrial
             fibrillation); myocardial infarction within the past 6 months

          -  Uncontrolled narrow-angle glaucoma

          -  Pregnant or breast feeding

          -  Serious or unstable medical condition that could likely lead to hospitalization during
             the course of the study or compromise study participation