Study Evaluating the Safety & Efficacy of DVS-223 SR for Relief of Vasomotor Symptoms Associated With Menopause

Inclusion Criteria: 1. Generally healthy, postmenopausal women; at least 12 months of spontaneous amenorrhea or at least 6 months of spontaneous amenorrhea with serum FSH levels \> 40 mIU/mL or at least 6 weeks postsurgical bilateral oophorectomy (with or without hysterectomy). 2. Minimum of 7 moderate to severe hot flushes per day or 50 moderate to severe hot flushes per week at screening: * Moderate hot flush: warm sensation with sweating, does not disrupt activity. * Severe hot flush: hot sensation with sweating, disrupts activity. 3. Subjects must have body mass index (BMI) less than or equal to 40 using the nomograph for BMI. Exclusion Criteria: 1. Hypersensitivity to venlafaxine (Effexor or Effexor XR). 2. Use of oral estrogen-, progestin-, androgen-, or SERM-containing drug products within 8 weeks prior to screening; use of transdermal hormone products within 8 weeks prior to screening; use of vaginal hormone products (rings, creams, gels) within 4 weeks prior to screening; use of intrauterine progestins within 8 weeks prior to screening; use of progestin implants or estrogen injectables within 3 months prior to screening; use of estrogen pellet or progestin injectables within 6 months prior to screening. 3. History of a seizure disorder other than a single childhood febrile seizure.