The key difference between tamsulosin and alfuzosin is that tamsulosin is an alpha (α)-1- blocker that is highly selective for the α1-adrenergic receptor that is predominantly found in smooth muscles of the prostate and bladder neck. At the same time, alfuzosin has a less selective binding profile with α1-adrenergic receptors and can affect α1B receptors.
Tamsulosin and alfuzosin are generally prescribed to treat benign prostatic hyperplasia (PBH), especially among men. BPH is a condition in which benign growth or hyperplasia of the prostate leads to lower urinary tract symptoms, including urgency, frequency, and changes to urine flow. Both tamsulosin and alfuzosin are alpha-1- adrenergic blockers that work by relaxing the prostate and bladder neck muscles. Both drugs are taken once daily, leading to improved urine flow and reduced symptoms of BPH. However, alfuzosin can be associated with lower blood pressure compared to tamsulosin. It is important to note that both medications should be taken as healthcare professionals prescribe. In addition, regular medical checkups are necessary to monitor their efficacy and any potential side effects.
CONTENTS
1. Overview and Key Difference
2. What is Tamsulosin
3. What is Alfuzosin
4. Similarities – Tamsulosin and Alfuzosin
5. Tamsulosin vs. Alfuzosin in Tabular Form
6. Summary – Tamsulosin vs. Alfuzosin
What is Tamsulosin?
Tamsulosin is a selective alpha (α)1A adrenoceptor antagonist primarily prescribed for BHP. In addition, tamsulosin is prescribed to treat ureteral stones, prostatitis, and female voiding dysfunction. Tamsulosin relaxes the smooth muscles in the prostate to improve urine flow by blocking the α1A adrenoceptors and relaxes the detrusor muscles to prevent storage symptoms. It was first approved by the FDA in 1997.
Figure 01: Chemical Structure of Tamsulosin
Oral administration is the most common route of administration of tamsulosin, and 90% of the drug is absorbed in fasted patients. Approximately 94% to 99% of the absorbed drug is bound with plasma proteins such as alpha-1-acid glycoprotein. The drug is extensively metabolized by CYP3A4 and CYP2D6 in the liver. Both metabolized and unmetabolized tamsulosin is excreted in the urine and feces after 168 hours post-administration.
What is Alfuzosin?
Alfuzosin is another α1 adrenergic antagonist used to treat the signs and symptoms of benign prostatic hypertrophy. It selectively binds and inhibits the α1 adrenoceptors in the lower urinary tract to relax the prostate and bladder neck muscles. This results in improved urine flow and a reduction of urinary symptoms. Alfuzosin was first approved by the FDA in 2003.
Figure 02: Chemical Structure of Alfuzosin
Alfuzosin is well absorbed from the gastrointestinal tract under fed conditions. The absorbed drug moderately binds with serum albumin and serum alpha-glycoprotein. The drug is then extensively metabolized by the hepatic cytochrome enzymes such as CYP3A4 in the liver. Metabolized and non-metabolized forms of alfuzosin are mainly excreted in feces and urine. Overdose of alfuzosin leads to hypotension, and renal function should be monitored regularly.
What are the Similarities Between Tamsulosin and Alfuzosin?
- Tamsulosin and alfuzosin medications are used for treating benign prostatic hyperplasia (PBH).
- Both drugs work by selectively blocking the α-1 adrenergic receptors in the smooth muscles of the prostate and bladder neck.
- They are taken once daily, orally.
- Both tamsulosin and alfuzosin share similar potential side effects, such as dizziness, headache, nasal congestion, and abnormal ejaculation.
What is the Difference Between Tamsulosin and Alfuzosin?
Tamsulosin and alfuzosin are the antagonists of α-1 adrenergic receptors of the smooth muscles of the prostate and bladder neck. Therefore, these two drugs are commonly used for treating benign prostatic hyperplasia. Although the two medications belong to a similar drug class, there is a distinct difference between tamsulosin and alfuzosin. Tamsulosin is highly selective for the α-1A adrenoceptor, comparable to alfuzosin. Therefore, the efficacy of tamsulosin is comparatively higher than that of alfuzosin. In addition, due to the low selectivity with α-1A and binding with other receptors such as α-1B, alfuzosin has a greater potential to lower blood pressure. In contrast, no such effect is associated with tamsulosin. Therefore, it is essential to consider all these differences when prescribing tamsulosin and alfuzosin for treating BHP.
Below is a summary of the difference between tamsulosin and alfuzosin in tabular form for side-by-side comparison.
Summary – Tamsulosin vs Alfuzosin
Tamsulosin and alfuzosin are two medications used to treat benign prostatic hyperplasia. They are α-1 adrenoceptor blockers that relax the smooth muscles in the prostate and bladder neck. This relaxation leads to improved urine flow and reduced symptoms. However, they are differences, such as affinity to α-1A adrenoceptors, between these drugs. Tamsulosin has the highest affinity with the α-1A, thereby displaying the highest drug efficacy. In contrast, the efficacy of alfuzosin is low and creates low blood pressure conditions in the body. Despite the difference between tamsulosin and alfuzosin, both drugs have similar potential side effects, such as dizziness and headache. It is essential to consult a healthcare professional to determine the most suitable medication for individual needs.
Reference:
1. Dunn, Christopher J., et al. “Tamsulosin.” Drugs & Aging, vol. 19, no. 2, 2002, pp. 135–161.
2. Elhilali, Mostafa, et al. “Long-Term Efficacy and Safety of Alfuzosin 10 Mg Once Daily: A 2-Year Experience in ‘real-Life’ Practice.” BJU International, vol. 97, no. 3, 2006, pp. 513–519.
Image Courtesy:
1. “Alfuzosin” By Fvasconcellos – Own work (Public Domain) via Commons Wikimedia
2. “Tamsulosin Structure” By 陳弈豪 – Own work (Public Domain) via Commons Wikimedia