Selective Alfa 1
blockers ( Prazosin , Terazosin ,
Doxazosin , Tamsulosin , Alfuzosin )
Pharmacological action :
Where is he located?
Are there types of alpha?
- There are two parts to alpha 1 receptors, where alpha 1A and alpha 1B are present... 1B is found in the blood vessels, so it will receive the drug to treat hypotension, A1 is found in the bladder and urethra, so it will have a good effect on the prostate .
- Prazosin, terazosin and doxazosin are better, especially on alpha 1A receptors, as these drugs block receptors that are found in blood vessels and vasodilation because it is more specific than phenoxybenzyamine. Despite its advantages, its disadvantages were more because it affected the heart, in addition to nasal disorders such as congestion, runny nose, and others.
- Tamsulosin and Alfuzosin will not lead to a decrease in blood pressure and will not cause vasodilation because they specialize in alpha 1A receptors. This receptor is present in the prostate and bladder neck. When a block is made, urine will move normally and improve its pumping out of the body.
Uses :
- hypertension. (Alfa 1B
- For the elderly, in cases of enlarged prostate, who cannot be given anesthesia for operations .(Alfa 1A
Side effect :
- The first dose is the biggest cause of side effects on a sudden drop in blood pressure and it will lead to paleness in the face, so this medicine is given gradually.
- Dysfunction in ejaculation, and it may stop and turn towards the bladder, causing it to impede smooth muscle contraction.
- The usual effects such as headache, fatigue, lethargy, etc .
- Swelling of the eye and its protrusion outward is caused by (Floppy iris syndrome .
Precaution :
- This medicine is recommended before going to bed because of its side effects such as fatigue and headache (he does not have a job and he already needs to sleep until the morning, so the effect will be little .
- All of these drugs are excreted through the liver and then the kidneys in the urine, except for doxazosin, which is excreted in the waste and is considered to have the longest period of effect on the body.