Quality of Life Study Using Gabapentin Versus Venlafaxine in Treating Hot Flashes in Patients With Prostate Cancer

• compare toxicity rates between the gabapentin and venlafaxine treatment groups [ Time Frame: over a 6 month treatment period ] [ Designated as safety issue: Yes ]
  Toxicity rates will be compared between the two groups
• Assess changes in the hot flash scores for the two arms [ Time Frame: 6 month treatment period ] [ Designated as safety issue: No ]
  Assess percentage changes in the hot flash score from baseline to cycle 6 between gabapentin and venlafaxine in men with prostate cancer treated with for hot flashes related to androgen deprivation therapy
• Assess changes in quality of life using the Hot flash related Daily Interference Scale (HFRDIS) [ Time Frame: over the 6 month treatment period ] [ Designated as safety issue: No ]
  Assess percent change in quality of life from baseline to cycle 6, as measured by the Hot Flash Related Daily Interference Scale (HFRDIS) total score, between gabapentin and venlafaxine in men with prostate cancer treated for hot flashes related to androgen deprivation therapy.

The purpose of this study is to assess the change in quality of life over a 6 month period between gabapentin and venlafaxine in men with prostate cancer treated for hot flashes related to androgen deprivation therapy.

60 evaluable patients with prostate cancer currently receiving androgen ablation therapy or who have had an orchiectomy will be enrolled in this study. All patients will be randomized 1:1 (30 patients per treatment arm) to either receive gabapentin or venlafaxine. Treatment duration will be a total of 6 months. During those 6 months, study staff will evaluate frequency and intensity of hot flashes using hot flash score from hot flash diary every 28 days. Patients will also record side effects associated with either gabapentin or venlafaxine on their medication diaries. Study staff will record the severity of all adverse events reported. Patients will also complete the quality of life Functional Assessment of Cancer Therapy-Prostate (FACT-P) form at baseline, cycle 3, and cycle 6/off study.

• Drug: Gabapentin
  Gabapentin will be administered orally at a starting dose of 300mg at bedtime (titration encouraged to desired effect and tolerability per treating physician). Maximum dose allowed will be 300mg three times a day. One cycle is defined as 28 +/- 7 days.
  Other Names:

  • Fanatrex
  • Gabarone
  • Gralise
  • Horizant
  • Neurontin
• Drug: Venlafaxine
  Venlafaxine will be administered orally at the starting dose of 37.5mg daily (titration allowed to desired effect and tolerability per treating physician). Maximum dose allowed will be 75mg per day. One cycle is defined as 28 +/- 7 days.
  Other Name: Effexor

• Experimental: Arm A: Gabapentin
  Gabapentin will be administered orally at a starting dose of 300mg at bedtime (titration encouraged to desired effect and tolerability per treating physician). Maximum dose allowed will be 300mg three times a day. One cycle is defined as 28 +/- 7 days.
  Intervention: Drug: Gabapentin
• Experimental: Arm B: Venlafaxine
  Venlafaxine will be administered orally at the starting dose of 37.5mg daily (titration allowed to desired effect and tolerability per treating physician). Maximum dose allowed will be 75mg per day. One cycle is defined as 28 +/- 7 days.
  Intervention: Drug: Venlafaxine

Inclusion Criteria:

• Men 18 years or older with histologically proven adenocarcinoma of the prostate

• Prior or current androgen deprivation for at least 6 months prior to study entry with either bilateral orchiectomy or being maintained on a stable dose of LHRH (luteinizing hormone-releasing hormone) agonist or antagonist

  • Hot flash frequency of an average of 2 or more per day (average of 14 hot flash episodes per week)

Exclusion Criteria:

• cannot currently be taking serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs) or monoamine oxidase inhibitors (MAOIs)

  • cannot have uncontrolled hypertension
  • cannot have history of past or current of epilepsy, epilepsy syndrome or other seizure disorder
  • cannot have psychiatric history of mania, hypomania, bipolar disorder or anorexia nervosa
  • cannot be receiving concurrent treatment with amy medications or herbal products being used with the express purpose of treating hot flashes.