Open-Label Drug Interaction Study Evaluating Desvenlafaxine Succinate Sustained Release (DVS SR) 100mg On The Pharmacokinetics Of Tamoxifen When Coadministered To Healthy Post-Menopausal Female Subjects

An Open-Label, 2-Period Sequential Drug Interaction Study To Evaluate The Effect Of A 100 Mg Dose Of Desvenlafaxine SR On The Pharmacokinetics Of Tamoxifen When Co-Administered In Healthy Post-Menopausal Female Subjects

The goal of this study is to evaluate the effect of multiple doses of Desvenlafaxine SR on the pharmacokinetics of Tamoxifen and endoxifen when coadministered to healthy post-menopausal female subjects. This study will also evaluate the safety and tolerability of Desvenlafaxine SR and Tamoxifen when coadministered to healthy post-menopausal female subjects.

Inclusion Criteria:

• Healthy post-menopausal female subjects, at least 45 years of age, with confirmed post-menopausal status
• Hysterectomized subjects
• Body Mass Index (BMI) less than or equal to 34.0 kg/m2
• Nonsmoker or smoker of fewer than 5 cigarettes per day as determined by history
• An informed consent document signed and dated by the subject

Exclusion Criteria:

• History of significant blood, kidney, endocrine, lung, gastrointestinal, heart, liver, psychiatric, neurologic, or allergic disease
• Presence or history of deep vein thrombosis or transient ischemic attack
• History of seizure disorder
• Presence or history of glaucoma or increased intraocular pressure
• Allergy to or unable to tolerate tamoxifen, desvenlafaxine, or venlafaxine
• History of substance abuse within 1 year of study
• A positive urine drug screen
• Treatment with an investigational drug within 30 days
• Consumption of grapefruit or grapefruit related citrus fruits
• 12 lead ECG demonstrating QTc >450 msec at screening
• Pregnant or nursing females
• Use of prescription or nonprescription drugs and dietary supplements
• History of sensitivity to heparin or heparin induced thrombocytopenia
• Severe acute or chronic medical or psychiatric condition or laboratory abnormality
• Use of CYP 2D6 inhibitors and CYP 3A4 inhibitors/inducers