What it is and what it is used for
Alfuzosin is a selective antagonist of post-synaptic alpha-1 adrenergic receptors, located in the prostate, at the base and neck of the bladder, in the prostatic part of the urethra and in the prostatic capsule.
Alfuzosin is used to treat the symptoms of benign prostatic hyperplasia and to treat hypertension .
Action Mechanism
The mechanism of action of alfuzosin is very simple: the drug binds to alpha-1 adrenergic receptors in a selective and competitive way, thus inducing the relaxation of the smooth muscle in which the receptors in question are present; the relaxation of the smooth muscles of the blood vessels causes a decrease in blood pressure, while the relaxation of the smooth muscles of the bladder, urethra and prostate helps to alleviate, or at least diminish, the symptoms of benign prostatic hyperplasia.
Effectiveness and Safety Studies
Alfuzosin has been approved for the treatment of benign prostatic hyperplasia symptoms by the Food and Drug Administration (FDA, which is the highest authority overseeing US drug and food law) in 2003. In the United States, alfuzosin is marketed by the pharmaceutical company Sanofi Aventis under the registered name of Uroxatral ®, while in other countries, including Italy, it is marketed under the registered name of Xatral ®; in Egypt, finally, it is marketed under the registered name of Prostetrol ®.
Alfuzosin has a particular selectivity for alpha-adrenergic receptors found in the lower urinary tract. And it is precisely by blocking these receptors that there is relaxation of the smooth muscles of the bladder neck and prostate, thus leading to an improvement and an increase in urinary flow, the reduction of which is one of the most annoying symptoms associated with benign prostatic hyperplasia .
To evaluate the pharmacokinetic properties of alfuzosin, several studies have been performed on healthy volunteers and on patients with benign prostatic hyperplasia; one of these studies considered treatment with daily doses of 7.5 mg and 30 mg in healthy volunteers, while patients with benign prostatic hypertrophy were treated with daily doses of 7.5 mg and 15 mg in different control groups.
The absolute drug bioavailability observed for prolonged-release alfuzosin tablets is 49% on a full stomach. From the study it was noted that the maximum plasma concentration of alfuzosin, when using prolonged-release tablets, is reached about eight hours after taking it, always on a full stomach. Another characteristic of alfuzosin prolonged-release tablets is that they have an almost linear kinetics after the administration of single or multiple doses that do not exceed the total of 30 mg. The study noted that the absence of food in the stomach reduces the absorption of alfuzosin up to 50%, compared to the same doses administered on a full stomach. For this reason it is recommended to take the drug on a full stomach and every day at the same meal, so as to facilitate the creation of a useful routine and to maintain a plasma concentration of quasi-constant alfuzosin. both to remember to take the drug (given that a good part of patients being treated for benign prostatic hyperplasia, being elderly, may have memory problems). In elderly patients attention must also be paid to the dose of alfuzosin administered, because clinical studies conducted on patients suffering from benign prostatic hyperplasia have shown differences in plasma drug concentration levels depending on the age of the various patients; in fact, it has been noted that in subjects over the age of 75, plasma concentration levels of a therapeutic dose of alfuzosin are approximately 35% higher than in patients under 65 years of age.
Posology and method of use
There are different doses of alfuzosin on the market, starting from 2.5 mg, 5 mg or 10 mg. The various dosages can be used in the treatment of arterial hypertension, and are useful in performing personalized treatments based on the severity of hypertension. For the treatment of benign prostatic hyperplasia, on the other hand, the recommended dose of alfuzosin is 10 mg / day, to be taken only once a day, after meals. Extended release tablets should not be divided, chewed or damaged in any way, and should be swallowed with a sufficient amount of water or other liquids. Incorrect administration may lead to undesired release and absorption of the active ingredient, with the risk of early adverse events. In patients who are already on medication for arterial hypertension, treatment of benign prostatic hyperplasia symptoms should be initiated by adjusting the dose of administered alfuzosin, due to the latter's known antihypertensive properties. Also in the case of patients over 75 years of age, attention must be paid to the dose of alfuzosin administered, because from some clinical studies it has been noticed that in individuals falling into this age group the plasma concentration levels of alfuzosin tend to be greater up to 30% compared to the values of other patients.
Since a large part of alfuzosin is eliminated via the kidneys, it is advisable to pay particular attention to patients with severe renal insufficiency and, if possible, not to treat them with alfuzosin, since there are insufficient data on the clinical safety of the drug in this group of patients. It is also inadvisable to use the 10 mg / day dose of alfuzosin in patients suffering from severe liver failure.
Alfuzosin: side effects and contraindications »
