Cialis (tadalafil) and Viagra (sildenafil) are drugs for the treatment of male erectile dysfunction (ED). Here are some of their characteristics.
Gui í a de Salud Masculina
I. the mechanism of drug action
1 、Identical point
Both of them belong to type 5 phosphodiesterase (PDE5) inhibitors. The physiological mechanism of penile erection involves the release of nitric oxide (NO) in the sponge during sexual stimulation, and NO activates guanosine cyclase to increase the synthesis of cyclic guanosine monophosphate (cGMP). CGMP can relax the smooth muscle of the corpus cavernosum and flow into the cavernous body to cause erection, while PDE5 can decompose cGMP,Cialis and Viagra to enhance erectile function by inhibiting PDE5 and increasing the level of cGMP.
2 、Differences
Action duration
Viagra (sildenafil)The duration of action is relatively short. Sildenafil usually lasts about 4-5 hours. It is taken on demand about 1 hour before sexual activity, and its effective time in the body is within a few hours.
Cialis (Tadalafe)The effect lasts for a long time, and the effective time of tadalafil can be as long as 36 hours, which is called "weekend pill", which means that patients are likely to achieve and maintain an erection during a long time window after taking the drug.
II. Drug use
1 、Mode of taking
Viagra (sildenafil)The recommended dose is 50mg, which can be adjusted according to individual response and tolerance. it is generally taken on demand about 1 hour before sexual activity, and it is absorbed more quickly on an empty stomach. Eating, especially a high-fat diet, may delay the onset time.
Cialis (Tadalafe)There are two ways of taking it on demand and taking it regularly once a day. When taking it as needed, it is recommended to take 10mg 30 minutes-1 hour before sexual activity. For patients who take it regularly once a day, the recommended dose is 2.5-5mg, which can maintain a stable blood concentration and improve patients' ability to respond to sexual stimulation.
2 、Side effect
Viagra (sildenafil):
Common side effects include headache, facial flushing, indigestion, nasal congestion, visual abnormalities (such as light vision, enhanced light perception or blurred vision, etc.). Visual abnormalities are relatively special side effects of sildenafil, mainly because they also have a certain inhibitory effect on PDE6 in the retina, but this is relatively rare.
Cialis (Tadalafe):
-the side effects are relatively mild, such as headache, indigestion, back pain, myalgia and so on. Tadalafil rarely causes adverse reactions such as visual abnormalities, because it has a relatively high selectivity to PDE6 and has little effect on retinal function.
These drugs must be used under the guidance of a doctor and are not suitable for use with certain drugs (such as organic nitrates) to avoid serious adverse reactions such as hypotension.