Pilot Study of Cyclobenzaprine for Treatment of Sleep Disturbance in Aromatase Inhibitor-treated Breast Cancer Patients

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