CIALIS TADALAFIL: All You Need to Know
Gui í a de Salud Masculina
Cialis (tadalafil, tadalafil) is a drug for the treatment of erectile dysfunction (ED) and lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH).
I. the mechanism of action
1 、Effect on erectile dysfunction
Tadalafil is a selective phosphodiesterase 5 (PDE5) inhibitor. During sexual stimulation, the nerve endings in the penile sponge release nitric oxide (NO). NO activates guanylate cyclase, which increases the level of cyclic guanosine monophosphate (cGMP), resulting in smooth muscle relaxation, blood flow into penile tissue and erection.
While PDE5 can degrade cGMP, tadalafil helps to maintain penile erectile function by inhibiting PDE5 and increasing the concentration of cGMP.
2 、Effect on lower urinary tract symptoms associated with benign prostatic hyperplasia
-there is PDE5 in the prostate and bladder neck. Tadalafil can relax the smooth muscle of the prostate after inhibiting PDE5, thus improving the symptoms of lower urinary tract caused by benign prostatic hyperplasia, such as dysuria, frequent urination, urgent urination and so on.
2. Characteristics of pharmacokinetics
1 、Absorption
Tadalafil is absorbed quickly after oral administration. On an empty stomach, the plasma concentration reaches the peak after about 2 hours. When taken with a high-fat diet, the absorption is delayed and the peak time can be extended to about 6 hours. However, the total degree of absorption (bioavailability) is not affected.
2 、Distribution
Tadalafil has a high protein binding rate of about 94%, which mainly binds to plasma proteins, and the drug can be distributed to all tissues of the body, including effective concentrations in the corpus cavernosum tissue.
3 、Metabolism and excretion
Tadalafil is mainly metabolized by cytochrome P450 (CYP) 3A4 enzyme in the liver, and a small amount is metabolized by CYP2C9. Its metabolites are inactive, mainly excreted in feces in the form of metabolites (about 61%), and a small part are excreted in urine (about 36%). Its half-life is longer, about 17.5 hours, which makes its action in the body for a relatively long time.
Matters needing attention in use
1 、Contraindication
-Tadalafil is prohibited in patients who are taking any form of nitrates (such as nitroglycerin, isosorbide dinitrate, etc.) because a combination of the two can lead to severe hypotension.
-it is forbidden for people who are allergic to tadarafi.
2 、Adverse reaction
Common adverse reactions include headache, indigestion, back pain, myalgia, nasopharyngitis, etc. These adverse reactions are usually mild to moderate and usually relieve themselves after withdrawal.
-in a few cases, serious adverse reactions such as abnormal vision (such as non-arterial anterior ischemic optic neuropathy) and hearing loss may occur, but these cases are rare.
3 、Dosage and usage
For the treatment of erectile dysfunction, the initial dose of 10mg is recommended when taken on demand, about 30 minutes-1 hour before sexual activity. Depending on the efficacy and tolerance of the individual, the dose can be increased to 20mg or reduced to 5mg, or you can choose to take it regularly once a day. The recommended dose is 2.5-5mg.
For the treatment of lower urinary tract symptoms associated with benign prostatic hyperplasia, the recommended dose is 5mg, once a day.
Before using tadalafil, patients should consult their doctor, who will evaluate the suitability for use and determine the appropriate dose and usage according to the patient's specific conditions (such as age, health status, other drugs being taken, etc.).