Vidalista 20mg: All You Need to Know
I. basic information of drugs
1 、Composition and mechanism of action
The main component of Vidalista 20mg is tadalafil (tadalafil), a phosphodiesterase-5 (PDE-5) inhibitor.
In male reproductive organs, sexual stimulation promotes the release of nitric oxide (NO) from nerve endings. NO activates guanylate cyclase and increases the level of cyclic guanosine monophosphate (cGMP), resulting in relaxation of corpus cavernosum smooth muscle and blood flow into the corpus cavernosum, resulting in erection. PDE-5 can degrade cGMP, while tadalafil helps to maintain penile erection by inhibiting PDE-5 and increasing the concentration of cGMP.
2 、Indication
-mainly used in the treatment of male erectile dysfunction (ED).
3 、Usage and dosage
It is generally recommended that the initial dose is 10mg. Depending on the efficacy and tolerance of the individual, the dose can be increased to 20mg or reduced to 5mg. It can be taken as needed about 30 minutes to 12 hours before sexual activity, with a maximum frequency of once a day.
-for elderly patients (aged 65 and above) and patients with hepatorenal insufficiency, the dose may need to be adjusted.
4 、Drug metabolism and excretion
Tadalafil was absorbed rapidly after oral administration and reached the plasma peak concentration about 2 hours after administration.
The absolute bioavailability of tadalafil is not clear. It is mainly metabolized by the liver. The main metabolic enzyme is cytochrome P450 3A4 (CYP3A4). The metabolites are inactive and are mainly excreted in feces in the form of metabolites and a small amount in urine.
5 、Drug interaction
-combination with organic nitrates (such as nitroglycerin, isosorbide dinitrate, etc.) is taboo because the combination of the two can lead to severe hypotension.
-combined with CYP3A4 inhibitors (such as ketoconazole, itraconazole, ritonavir, etc.) can increase the blood concentration of tadalafil and increase the risk of adverse reactions; combined with CYP3A4 inducers (such as rifampicin) can reduce the blood concentration of tadalafil, which may affect the efficacy.
-when used in combination with α-blockers (such as tamsulosin, etc.), it may increase the risk of hypotension and should be used with caution.
6 、Adverse reaction
Common adverse reactions include headache, indigestion, back pain, myalgia, nasal congestion, flushing, etc., which are usually mild to moderate and transient.
-the rare adverse reactions may be abnormal vision (such as blurred vision, color vision changes, etc.), hearing loss, etc., but the incidence is low.
7 、Matters needing attention
-if patients have cardiovascular disease, careful assessment should be taken before using Vidalista 20mg, as sexual activity itself poses a risk to patients with cardiovascular disease, and drugs may cause changes in blood pressure.
-it is forbidden for people who are allergic to tadarafi.
-this drug should not be used in women and children.