The place of drugs in the treatment of benign prostatic hyperplasia
To begin urinating, the muscles of the bladder wall must contract and the muscles of the bladder neck at the beginning of the urethra must relax. Alpha bladder neck muscle chemical receptors They are called 1 and inhibiting these receptors causes the muscle to relax and prepare to urinate. A class of drugs called alpha blockers (alpha blockers) was first used about 40 years ago. Phenoxybenzamine was one of the first drugs to be used as an alpha receptor inhibitor. Of course, this drug was non-specific and in addition to the bladder, it also affected other parts, including the cardiovascular system, and caused other side effects.
After a while, prazosin entered the market, which was more specific than phenoxybenzamine and had fewer side effects. Prazosin is available in 1 mg and 5 mg tablets, some of which can be used to treat the disease depending on the patient’s blood pressure (this drug lowers blood pressure) as well as the severity of clinical symptoms. This drug can cause side effects such as hypotension when getting up for the first time. Therefore, the doctor and pharmacist advise the patient to use it in the first days of use with the least possible amount and of course at night. After 2 to 3 days when the patient’s body gets used to it, it can be used in larger quantities and more often. There are patients whose clinical symptoms disappear with only one 1 mg tablet day and night. On the other hand, there are patients who need to take 5 mg twice a day, ie 10 mg per day.
The trazosin tablet that came on the market after prazosin works with the same mechanism as prazosin, but the difference is in the duration of the effect, in that prazosin is called short-acting and terazosin is long-acting. Trazosin is available in 2 and 4 mg tablets and its side effects are the same as prazosin.
Another drug used to treat benign prostatic hyperplasia is finasteride. For the mechanism of action of finasteride, let’s go back a bit. At the beginning of the article, we mentioned that testosterone is made by the testicles and enters the bloodstream to create secondary sexual characteristics such as body shape and masculine appearance. Another function of testosterone is to affect and enlarge prostate cells. Testosterone does a lot of its work by converting to dihydrotestosterone. The enzyme responsible for converting testosterone to dihydrotestosterone is called 5-alpha reductase. If a drug can inhibit this enzyme, it will prevent the effect of testosterone on the prostate. Inhibit this group of drugs
They are called 5-alpha reductase and finasteride belongs to this group of drugs.
Finasteride has another function, but it is used with smaller amounts of the drug. The type of hair loss that causes men to lose hair on the front and top of the head is called androgenic hair loss (male hormone). This type of hair loss is due to the effect of testosterone and dihydrotestosterone on the hair follicles. Finasteride inhibits the conversion of testosterone to dihydrotestosterone by inhibiting the enzyme 5-alpha reductase, which results in some inhibition of hair loss in this particular form. However, due to various side effects such as erectile dysfunction, the amount of medicine and the time of its use should be adjusted according to the doctor’s opinion and taking into account the condition of each person.
We should know that a high percentage of patients with benign prostatic hyperplasia respond well to finasteride, but sometimes you have to wait at least 3 months to see this effect. It should be noted that the effects of these drugs disappear after discontinuation of the drug and clinical signs recur.
This article by Dr. Salam Medical Journal Translators Team It is provided. Use it only by mentioning the source Dr. Salam (hiDoctor.ir) Is allowed