From the Guidelines
Cardura (doxazosin) is a prescription medication that belongs to a class of drugs called alpha-1 blockers, used to treat high blood pressure (hypertension) and benign prostatic hyperplasia (BPH), an enlarged prostate, by relaxing blood vessels and the muscles in the prostate and bladder neck. For hypertension, the typical starting dose is 1 mg once daily, which may be gradually increased to 2-16 mg daily based on blood pressure response, as indicated in the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1. For BPH, treatment usually begins with 1 mg daily, potentially increasing to 8 mg daily. Cardura is taken orally, usually once daily, and can be administered with or without food. Common side effects include dizziness, headache, drowsiness, and low blood pressure, particularly when standing up quickly (orthostatic hypotension), as noted in the studies 1. This medication works by blocking alpha-1 receptors, preventing norepinephrine from constricting blood vessels and relaxing smooth muscle in the prostate, which improves urine flow in men with BPH. Patients should be aware that the first dose may cause significant dizziness or fainting, so it's often recommended to take the initial dose at bedtime. The AUA guideline on management of benign prostatic hyperplasia recommends offering alpha blockers, including doxazosin, as a treatment option for patients with bothersome, moderate to severe LUTS/BPH, considering patient age and comorbidities, and different adverse event profiles 1. Additionally, combination therapy with an alpha-adrenergic receptor blocker and a 5 alpha-reductase inhibitor may be considered for patients with LUTS associated with demonstrable prostatic enlargement, as it has been found to be effective in relieving and preventing the progression of symptoms, and reducing the long-term risk of acute urinary retention and the need for BPH-related surgery 1.
From the FDA Drug Label
Doxazosin tablets, USP are indicated for the treatment of the signs and symptoms of BPH. Doxazosin tablets, USP are indicated for the treatment of hypertension, to lower blood pressure.
Cardura (doxazosin) is a medication used to treat Benign Prostatic Hyperplasia (BPH) and hypertension.
- It is a selective inhibitor of the alpha 1 subtype of alpha-adrenergic receptors.
- It is available as colored tablets for oral use and contains 1 mg, 2 mg, 4 mg, and 8 mg of doxazosin as the free base 2.
From the Research
What is Cardura (Doxazosin)
- Cardura, also known as doxazosin, is a selective alpha-1 adrenergic blocker used to treat benign prostatic hyperplasia (BPH) and hypertension 3, 4, 5.
- It works by reducing the tone of prostatic smooth muscle, thereby improving urinary flow and relieving symptoms of BPH 3, 4.
- Doxazosin can be given in a convenient once-daily dose and its efficacy is maintained in the long term 3.
- It is also effective in treating hypertension, particularly in men with both BPH and hypertension 4, 5.
- The use of doxazosin has been shown to improve urinary flow and reduce blood pressure in hypertensive patients, while having minimal effects on blood pressure in normotensive patients 4.
Mechanism of Action and Effects
- Doxazosin reduces the tone of prostatic smooth muscle, leading to improved urinary flow and relief of BPH symptoms 3, 4.
- It also decreases blood pressure by blocking alpha-1 adrenergic receptors, making it an effective treatment for hypertension 4, 5.
- The effects of doxazosin on urinary flow are similar in both hypertensive and normotensive patients 4.
- Combination therapy with doxazosin and finasteride has been shown to improve LUTS and reduce the risk of overall clinical progression of BPH compared to each drug separately 6.
Safety and Tolerability
- Doxazosin is generally well tolerated, with most side effects being mild or moderate 4, 7, 6.
- Common side effects include dizziness, fatigue, and postural hypotension 7, 6.
- The use of doxazosin has been shown to be safe and effective in the treatment of BPH, with minimal interactions with antihypertensive therapy 7.