cialis levitra vs Bayer) and tadalafil (Cialis cialis levitra vs, Lilly ICOS) cialis levitra vs, have completed extensive clinical testing cialis levitra vs, and both drugs have gained FDA's approval. Both are inhibitors of type 5 phosphodiesterase (PDE-5) cialis levitra vs, thus sharing the same basic mechanism of sildenafil (Viagra cialis levitra vs, Pfizer) cialis levitra vs, which was approved in March cialis levitra vs, 1998. All three are taken orally prior to planned sexual activity cialis levitra vs, acting to increase blood flow in the penis in response to sexual stimulation. However cialis levitra vs, there are important differences between the three cialis levitra vs, differences that could influence safety cialis levitra vs, specificity cialis levitra vs, duration of action cialis levitra vs, and ultimately cialis levitra vs, public acceptance within this class of drug. Giles Brindley and Drug Therapy for ED M cialis levitra vs.
cialis levitra vs Odern drug therapy for ED was advanced enormously in 1983 when British physiologist Giles Brindley cialis levitra vs, Ph.D. dropped his trousers and demonstrated to a shocked AUA audience his phentolamine-induced erection. The drug Brindley injected into his penis was a non-specific vasodilator cialis levitra vs, an alpha-blocking agent cialis levitra vs, and the mechanism of action was clearly corporal smooth muscle relaxation. The effect that Brindley discovered cialis levitra vs, established the fundamentals for the later development of specific cialis levitra vs, safe cialis levitra vs, orally-effective drug therapies cialis levitra vs, ie cialis levitra vs, PDE-5 inhibitors. PDE Inhibition and Smooth Muscle Relaxation Phosphodiesterase (PDE) is an enzyme that causes breakdown of cyclic GMP cialis levitra vs, which is the direct intracellular mediator in the nitric oxide (nonadrenergic cialis levitra vs, noncholinergic) pathway. Discovery of this pathway led to a Nobel Prize in 1998 for the scientists responsible. The nitric oxide system causes relaxation of smooth muscle in blood vessel walls cialis levitra vs, ie cialis levitra vs, vasodilation cialis levitra vs, in various organ systems. The direct intracellular mediator of the nitric oxide pathway is cGMP. PDE catalyzes the degradation of cGMP. This pathway is active in numerous organ systems cialis levitra vs, and as of this writing cialis levitra vs, a number of different PDEs are known. The various PDEs differ in their physiologic roles and tissue distribution. Type 5 PDE is concentrated in the penile smooth muscle .
cialis levitra vs H is the direct intracellular mediator in the nitric oxide (nonadrenergic cialis levitra vs, noncholinergic) pathway. Discovery of this pathway led to a Nobel Prize in 1998 for the scientists responsible. The nitric oxide system causes relaxation of smooth muscle in blood vessel walls cialis levitra vs, ie cialis levitra vs, vasodilation cialis levitra vs, in various organ systems. The direct intracellular mediator of the nitric oxide pathway is cGMP. PDE catalyzes the degradation of cGMP. This pathway is active in numerous organ systems cialis levitra vs, and as of this writing cialis levitra vs, a number of different PDEs are known. The various PDEs differ in their physiologic roles and tissue distribution. Type 5 PDE is concentrated in the penile smooth muscle o.
cialis levitra vs
|