Conditions: Hypertension Female Sexual Dysfunction
Keywords: sexual dysfunction female hypertension high blood pressure beta blockers metoprolol nebivolol Bystolic Toprol XL
Allocation: NON_RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 29
Healthy volunteers: no

Brief summary:
Beta-blockers (BB) are an important treatment for high blood pressure and heart disease. However beta-blockers can cause sexual dysfunction (SD) and this common side effect limits successful use of this class of medications. Sexual side effects often result in drug discontinuation, compromising therapy goals. The investigators are conducting the study to determine if nebivolol, a newer beta blocker that is selective for receptors in the heart and causes vasodilation in the body causes fewer sexual side effects, or even improves sexual function, compared with metoprolol succinate.

Detailed description:
This protocol is designed to compare the effects two beta blockers, nebivolol (Bystolic) 5-10 mg daily with metoprolol succinate (Toprol XL) 100-200 mg daily on sexual function in post-menopausal women with high blood pressure. The study is composed of 2 treatment phases. At baseline subjects are randomized to either nebivolol 5 mg once daily or metoprolol succinate 100 mg once daily. After randomization, subjects are treated for 12 weeks with double blind therapy. Following double-blind therapy subjects enter a 2-week washout phase and are subsequently switched to the alternate therapy.

After 4 weeks (visits 3 and 7) of double-blind treatment with either nebivolol 5 mg once daily or metoprolol succinate 100 mg once daily subjects will be evaluated and the need for dosage titration assessed. If blood pressure is not at goal the dosage of study medication will be doubled to nebivolol 10 mg once daily or metoprolol succinate 200 mg once daily. If blood pressure remains uncontrolled after 8 weeks of double blind treatment with study medication open label amlodipine 5 mg will be initiated (visits 4 and 8) at the discretion of the principal investigator. During double blind treatment subjects will be evaluated in clinic every 4 weeks.

The primary efficacy variable is the change from baseline in Changes in Sexual Functioning Questionnaire (CSFQ) and the Female Sexual Function Index (FSFI).

The primary study objective is to determine whether nebivolol causes fewer sexual side effects compared with metoprolol succinate and if nebivolol improves FSF in women. FSF will be assessed with the above questionnaires-FSFI and CSFQ.

Arms:
arm 1: Nebivolol 5 mg daily for 12 weeks followed by Metoprolol succinate 100 mg daily for 12 weeks. A two week washout (no medication) is completed prior to switching to metoprolol. arm 2: Metoprolol succinate 100 mg daily for 12 weeks followed by nebivolol 5 mg daily for 12 weeks. A two week washout (no medication) is completed prior to switching to nebivolol.

Interventions: intervention 1: nebivolol and metoprolol succinate intervention 2: metoprolol succinate and nebivolol
Intervention descriptions: intervention 1: Subjects randomized to treatment Arm A will receive nebivolol 5 mg once daily for 12 weeks. After 12 weeks, double blind therapy will be discontinued and patients will undergo a wash-out period of study therapy over 2 weeks. Subjects randomized to treatment Arm A will then receive metoprolol succinate 100 mg once daily. Subjects will continue double blind therapy for a total duration of 12 weeks. intervention 2: Subjects randomized to treatment Arm B will receive metoprolol succinate 100mg once daily for 12 weeks. After 12 weeks, double blind therapy will be discontinued and patients will undergo a wash-out period of study therapy over 2 weeks. Subjects randomized to treatment Arm B will then receive nebivolol 5 mg once daily. Subjects will continue double blind therapy for a total duration of 12 weeks.

Protocol document: