About Alpha Blockers
Alpha-Adrenergic Antagonists, or alpha blockers, block the action of sympathetic nerves located on blood vessels. They do this by binding to the alpha-adrenoreceptors that are located on the smooth muscle. They are competitive antagonists to norepinephrine, which is released by sympathetic nerves. Because they antagonize or block, sympathetic activity, they are commonly known as sympatholytics. There are two types of alpha-adrenoceptors, alpha 1 (a1) and alpha 2 (a2). A1 receptors are found on the vascular smooth muscle, and a2 are located on sympathetic nerve terminals and on vascular smooth muscle.
Beginning in the late 1980s, doctors began studying alpha-adrenoreceptors for use in enlarged prostates. Alpha-adrenoreceptors are located in the prostate gland, which makes them an ideal target for alpha-adrenoreceptor blocking medications. Patients in these drug studies reported improved urine flow rates. The drug works by reducing prostate and bladder neck muscle contractions, leading to the lessening of symptoms. Many patients respond well to this treatment, and some find their symptoms largely disappear. The four alpha blockers most commonly used today include Alfuzosin (Uroxatral), Doxazosin (Cardura), Tamsulosin (Flomax), and Terazosin (Hytrin). While all four work equally as well, the four may vary in cost, and the choice between the four medications may depend on other medication the patient may be taken concurrently.
There are many advantages to pharmaceutical treatment of BPH. First and foremost, alpha blockers are a much less invasive treatment option than surgery for patients with an enlarged prostate. There are none of the risks associated with surgery, such as reactions to anesthesia or post-operative infection. In addition, there is no need for catheterization or post-op recovery time. Alpha blockers are ideal for men with mild to moderate BPH symptoms, and these medications lead to significant improvement in more than two-thirds of men who take them. If alpha blockers do not lessen symptoms, the patient will then likely choose a minimally invasive treatment such as the laser treatment options.
Alpha blockers are not a cure for BPH; they improve the symptoms of BPH. These medications must also be taken for life. In addition, at some point in time, some patients may become insensitive to these medications due to the continued growth of the prostate glands. If and when this occurs, the doctor may have to increase the dose of alpha blockers which also may increase their side effects. Your physician may also change your medication to a different type of alpha blockers. Additionally, many of these alpha blockers can lead to sexual and ejaculatory dysfunctions which may negatively impact a patient’s quality of life. With the availability of minimally invasive procedures, most patients will ultimately opt for surgical procedures as a treatment option.
Possible Drug Interactions and Side Effects
In addition to possible sexual and ejaculatory dysfunctions, several other side effects of alpha blockers may occur. These include hepatic (liver) impairment, as well as possible impairment while operating machinery (men should wait 24 hours after their first dose to see how they are responding to the treatment before driving). These drugs should also generally not be combined with diuretics, general anesthetics, MAOIs, and phosphodiesterase inhibitors. In addition, some patients may note dizziness (especially in elderly patients), weakness, headaches, lethargy, nausea, and gastrointestinal symptoms. Rare effects may include blurred vision, jaundice, and urinary incontinence. Patients should tell their doctor if they are planning to have eye surgery, as these medications can cause pupil disorders, as well as discuss usage of erectile dysfunction medication such as Viagra or Cialis, as the drugs may interact.
It is important for the physician to know if the patient is taking any other medication to lower blood pressure, and to warn the patient to monitor his response to the drug in the first 24 hours to ensure that they do not have an adverse reaction. If the patient feels dizzy or lightheaded, they should not drive or operate machinery. Finally, these drugs may vary greatly in their effect from patient to patient, so patients should be seen regularly to ensure that the drug and its dosage continue to be right for them.