What are the alpha blockers with the least side effects?

From the Guidelines

Tamsulosin is generally considered the alpha blocker with the least side effects for most patients, due to its selectivity for alpha-1A receptors found primarily in the prostate and bladder, resulting in fewer cardiovascular side effects. The typical dose is 0.4 mg taken once daily, preferably 30 minutes after the same meal each day 1. This selectivity makes tamsulosin particularly suitable for elderly patients or those with cardiovascular concerns. The most common side effect of tamsulosin is retrograde ejaculation (occurring in about 8-18% of men), but it rarely causes significant blood pressure drops that lead to falls.

Key Considerations

• When prescribing an alpha blocker for the treatment of LUTS/BPH, the choice of alpha blocker should be based on patient age and comorbidities, and different adverse event profiles (eg, ejaculatory dysfunction [EjD], changes in blood pressure) 1.
• Tamsulosin has a lower probability of orthostatic hypotension but a higher probability of ejaculatory dysfunction compared to other alpha blockers 1.
• For patients who experience ejaculatory problems with tamsulosin, alfuzosin (10 mg daily) may be an alternative with a slightly better sexual side effect profile while still maintaining relatively good cardiovascular tolerability.

Alternatives and Special Considerations

• Other alpha blockers such as doxazosin, terazosin, and silodosin may also be considered, but their use should be individualized based on patient-specific factors and potential side effects 1.
• In men with hypertension and cardiac risk factors, the use of an alpha blocker to manage LUTS should not necessarily be assumed to constitute optimal management of the patient’s concomitant hypertension, and separate management of hypertension may be required 1.

From the FDA Drug Label

The symptoms associated with benign prostatic hyperplasia (BPH) are related to bladder outlet obstruction, which is comprised of two underlying components: static and dynamic. The dynamic component is a function of an increase in smooth muscle tone in the prostate and bladder neck leading to constriction of the bladder outlet Smooth muscle tone is mediated by the sympathetic nervous stimulation of alpha 1 adrenoceptors, which are abundant in the prostate, prostatic capsule, prostatic urethra, and bladder neck. Blockade of these adrenoceptors can cause smooth muscles in the bladder neck and prostate to relax, resulting in an improvement in urine flow rate and a reduction in symptoms of BPH Tamsulosin, an alpha 1 adrenoceptor blocking agent, exhibits selectivity for alpha 1 receptors in the human prostate. Approximately 70% of the alpha 1 receptors in the human prostate are of the alpha 1A subtype.

• Alpha blockers with the least side effects are not explicitly compared in the provided drug labels.
• The labels provide information on tamsulosin 2 and terazosin 3, but do not directly compare their side effect profiles.
• Tamsulosin is described as an alpha 1 adrenoceptor blocking agent with selectivity for alpha 1 receptors in the human prostate.
• Terazosin is also an alpha blocker, but its label does not provide a direct comparison with tamsulosin in terms of side effects.

From the Research

Alpha Blockers with the Least Side Effects

The following alpha blockers have been identified as having a lower incidence of side effects:

• Tamsulosin: has selectivity for the alpha(1A) and alpha(1D) receptor subtypes, resulting in a decreased potential for cardiovascular adverse effects 4, 5
• Alfuzosin: although not receptor subtype selective, is clinically "uroselective" and does not significantly affect vascular alpha-adrenergic receptors, resulting in a lower incidence of side effects such as ejaculatory dysfunction 6, 4

Comparison of Alpha Blockers

A comparison of the available alpha blockers reveals that:

• Tamsulosin and alfuzosin have a lower incidence of side effects compared to other alpha blockers such as terazosin and doxazosin 6, 7, 4
• The newer, "uroselective" alpha blockers such as tamsulosin and alfuzosin have a decreased potential for cardiovascular adverse effects compared to older, more vasoactive agents 4
• Common adverse events with tamsulosin and alfuzosin include dizziness and asthenia, but these are generally less severe than those associated with other alpha blockers 4

Side Effects of Alpha Blockers

The side effects of alpha blockers can be significant, and include:

• Orthostatic hypotension 8, 4
• Dizziness 7, 4
• Headache 7
• Postural hypotension 7, 8
• Retrograde ejaculation 7
• Ejaculatory dysfunction 6