From the Guidelines
Doxazosin (Zosin) is an alpha-1 adrenergic blocker medication primarily used to treat high blood pressure and symptoms of benign prostatic hyperplasia (BPH) in men, with a recommended starting dose of 1 mg once daily, which may be gradually increased to 2-8 mg daily based on patient response 1.
Key Points
- Doxazosin works by relaxing blood vessels, allowing blood to flow more easily, and relaxing the muscles in the prostate and bladder neck, improving urinary flow and reducing symptoms like frequent urination, urgency, and weak stream.
- Common side effects include dizziness, lightheadedness, and fatigue, especially when starting treatment or increasing the dose.
- First-dose hypotension (a significant drop in blood pressure after the initial dose) is a notable concern, which is why it's typically taken at bedtime and started at a low dose.
- Patients should rise slowly from sitting or lying positions to minimize dizziness and should avoid driving or operating machinery until they know how the medication affects them.
- The choice of alpha blocker, including doxazosin, should be based on patient age and comorbidities, and different adverse event profiles, such as ejaculatory dysfunction and changes in blood pressure 1.
Medical Therapy
- Alpha blockers, including doxazosin, are a recommended treatment option for patients with bothersome, moderate to severe LUTS/BPH, with a moderate recommendation and evidence level of Grade A 1.
- Multiple phase III randomized control trials, phase IV studies, systematic reviews, and meta-analyses have demonstrated the efficacy of alpha blockers for LUTS and BPH since the 1980s, with all alpha blockers being relatively equally effective in terms of IPSS.
From the FDA Drug Label
Doxazosin mesylate is a quinazoline compound that is a selective inhibitor of the alpha 1 subtype of alpha-adrenergic receptors. Zosin is another name for Doxazosin, which is a medication used to treat the signs and symptoms of Benign Prostatic Hyperplasia (BPH) and hypertension.
- It works by relaxing the muscles in the prostate and bladder neck, making it easier to urinate.
- It also lowers blood pressure by reducing the resistance in blood vessels. 2, 2, 2
From the Research
What is Doxazosin (Zosin)
- Doxazosin, also known as Zosin, is a selective alpha 1-adrenoceptor antagonist used to treat benign prostatic hyperplasia (BPH) and hypertension 3, 4, 5, 6, 7.
- It works by relaxing the smooth muscle in the prostate and bladder neck, making it easier to urinate, and by reducing blood pressure by decreasing the resistance in blood vessels 3, 7.
Uses of Doxazosin
- Doxazosin is used to treat the symptoms of BPH, such as difficulty urinating, weak urine flow, and frequent urination 3, 5, 6.
- It is also used to treat high blood pressure, either alone or in combination with other medications 4, 7.
- Doxazosin has been shown to be effective in treating BPH in both normotensive and hypertensive patients 3, 6.
Benefits of Doxazosin
- Doxazosin has been shown to improve urinary flow rates and reduce symptoms of BPH 3, 5, 6.
- It has also been shown to lower blood pressure and reduce the risk of coronary heart disease 4, 7.
- Doxazosin is generally well-tolerated, with common side effects including dizziness, headache, and fatigue 3, 4, 5, 6.
Studies on Doxazosin
- A study published in the European Urology journal found that doxazosin was effective and safe in treating BPH in 456 patients 3.
- Another study published in the Journal of Urology found that doxazosin improved urinary flow rates and reduced symptoms of BPH in 248 hypertensive patients 5.
- A multicenter study published in the Journal of Urology found that doxazosin was effective in treating BPH in normotensive patients 6.
- A review article published in the Drugs journal found that doxazosin was a promising agent in the treatment of urinary symptoms associated with BPH and hypertension 7.