Side Effects
To many it might sound strange but the other available impotency drugs that focus on erectile dysfunction 
the side effects which they come with despite the fact that the mechanism with which Cialis and they work is the same but Cialis does not comes with the side effects those other impotency drugs come with; but unfortunately that does not means that Cialis is free from any side effects, here in Cialis the nature is a bit different of those adverse effects being reported but with the passage of time their impact minimizes.
Cialis and other impotency drugs for erectile dysfunction all act by inhibiting the PDE5 enzyme. These drugs also inhibit other PDE enzymes. Viagra and Levitra inhibit PDE6, an enzyme found in the eye, more than Cialis. Some Cialis users see a bluish tinge and are highly sensitive to light because of PDE6 inhibition. Viagra and Levitra also inhibit PDE1 more than Cialis. PDE1 is found in the brain, heart, and vascular smooth muscle. It is thought that the inhibition of PDE1 by Viagra and Levitra leads to vasodilatation, flushing, and tachycardia. Cialis inhibits PDE11 more than Viagra or Levitra. PDE11 is expressed in skeletal muscle, the prostate, the liver, the kidney, the pituitary gland, and the testes. The effects on the body of inhibiting PDE11 are not known.