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 prostate capsule.
Alfuzosin is used to treat symptoms of benign prostatic hyperplasia and to treat hypertension.
Action Mechanism
The mechanism of action of alfuzosin is very simple: the drug binds to the alpha-1 adrenergic receptors in a selective and competitive way, thus inducing relaxation of the smooth muscles in which the receptors in question are present; the relaxation of the smooth muscle of the blood vessels causes a decrease in blood pressure, while the relaxation of the smooth muscle of the bladder, urethra and prostate helps to relieve, or at least decrease, the symptoms of benign prostatic hyperplasia.
Efficacy and Safety Studies
Alfuzosin was approved for the treatment of symptoms of benign prostatic hyperplasia by the Food and Drug Administration (FDA, which is the highest authority overseeing US drug and food laws) in 2003. In the United States, alfuzosin it 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 ®; finally, in Egypt 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 the smooth muscles of the bladder neck and prostate relax, 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 were performed in healthy volunteers and in 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 the 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% in the fed state. The study found that the maximum plasma concentration of alfuzosin when using the prolonged-release tablets is reached approximately eight hours after taking it, always on a full stomach. Another feature of alfuzosin prolonged-release tablets is that they have almost linear kinetics after administration of single or multiple doses that do not exceed the total of 30 mg. The study found that the absence of food in the stomach reduces the absorption of alfuzosin by up to 50%, compared to the same doses given in a fed state. For this reason it is recommended to take the drug on a full stomach and at the same meal every day, to facilitate the creation of a useful routine and to maintain an almost constant plasma concentration of alfuzosin. and 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 the plasma concentration levels of the drug according to the age of the various patients; in fact, it has been noted that in subjects over 75 years of age, the plasma concentration levels of a therapeutic dose of alfuzosin are approximately 35% higher than in patients under the age of 65.
Dosage 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, however, the recommended dose of alfuzosin is 10 mg / die, to be taken once a day, after meals. The prolonged-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 can lead to unwanted release and absorption modes of the active ingredient, with the risk of early adverse events. In patients who are already on pharmacological treatment for arterial hypertension, the treatment of symptoms of benign prostatic hyperplasia should be initiated by adjusting the dose of alfuzosin administered, due to the known antihypertensive properties of the latter. Also in the case of patients over the age of. 75 years of age, attention must be paid to the dose of alfuzosin administered, because in some clinical studies it has been noted that in individuals within this age group the plasma concentration levels of alfuzosin tend to be up to 30% higher than the values of others patients.
Since a large part of alfuzosin is eliminated by the kidney, it is advisable to pay particular attention to patients with severe renal insufficiency and, if possible, not to treat them with alfuzosin, as there are insufficient data on the clinical safety of the drug in this group. It is also inadvisable to use the 10 mg / day alfuzosin dose in patients suffering from severe hepatic insufficiency.
Alfuzosin: side effects and contraindications "
