Tadalafil (Cialis) and sildenafil (Viagra) are both medications used to treat erectile dysfunction. They work by increasing blood flow to the penis, which allows for a firmer and long-lasting erection.

Tadalafil and sildenafil are medicines that are used to treat erectile dysfunction (ED).

1. Sildenafil (Viagra)

Mechanism for action:

-Sildenafil is a selective inhibitor of type 5 phosphodiesterase (PDE-5). PDE-5 is an enzyme that is responsible for degrading nitrogen monoxide (no)-dependent on cyclic monophosphate guanosin (cGMP) in the vascular smooth muscle of the penis. By inhibiting PDE-5, the concentration of cGMP increases, causing smooth muscle relaxation and increased blood flow to the penis, facilitating erection.

Dose and administration:

-it usually takes 30-60 minutes before sexual activity. The usual dose is 50 mg, but may be adjusted to 25 mg or 100 mg depending on tolerance and efficacy in each patient.

Side effects:

-they may include headache, facial blush, feeling hot, blurred vision (in rare cases), dyspepsia, and nasal congestion.

2. Tadalafil (Cialis)

Mechanism for action:

-similar to sildenafil, tadalafil is an PDE inhibitor-5. However, it has a longer duration of action.

Dose and administration:

-it can be taken without such strict planning as to the time before sexual activity compared to sildenafil. The recommended dose for SD is 10 mg, and in some cases may be adjusted to 5 mg or 20 mg.

Side effects:

-it can also cause headache, facial blush, abdominal pain, and lumbar pain, although the incidence and severity may vary compared to sildenafil.

It is important to note that these medicines should be prescribed by a doctor and used with caution, as they may interact with other medicines and are not suitable for all patients, for example those with certain serious heart disease or taking nitrates.