Tadalafil / Oxytocin ODT
Tadalafil
Similar to sildenafil and vardenafil, tadalafil is a selective phosphodiesterase (PDE) type 5 inhibitor. Male erectile dysfunction (ED), pulmonary arterial hypertension (PAH), benign prostatic hypertrophy (BPH), or the simultaneous therapy of ED and BPH, are all treated with it orally. Contrary to several drugs used to treat erectile dysfunction (such as alprostadil), tadalafil does not suppress prostaglandins. Tadalafil, which is more selective for PDE5 than for PDE6 found in the retina and differs from sildenafil in that it has not been linked to reports of visual abnormalities. Tadalafil appears to have a longer half-life of effect (up to 36 hours) than sildenafil and vardenafil for the treatment of ED. Because PDE inhibitors promote erection only in the presence of sexual stimulation, the longer duration of action of tadalafil allows for more spontaneity in sexual activity. According to ED treatment guidelines, oral phosphodiesterase type 5 inhibitors (PDE5 inhibitor) are considered first-line therapy.1 Tadalafil was in phase II trials for the treatment of female sexual dysfunction, however, further investigation was discontinued. FDA approval was granted November 2003 for treatment of male erectile dysfunction (ED), and in January 2008, approval was granted for once daily use without regard to timing of sexual activity. Tadalafil (Adcirca) was FDA approved for the treatment of pulmonary arterial hypertension (PAH) in May 2009. In clinical studies of patients with pulmonary arterial hypertension (PAH), tadalafil-treated patients experienced improved exercise capacity and less clinical worsening compared to placebo. In October 2011, tadalafil received FDA approval for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH) and for the concurrent treatment of erectile dysfunction and BPH.
Oxytocin
Oxytocin is a neurohypophyseal peptide, well known for its hormonal role in lactation and parturition but also plays a significant role in copulatory and erectile behavior. It was discovered and synthesized by Nobel Prize winner Du Vigneaud and colleagues in the 1950s. Oxytocin is made up of nine amino acids. The synthesis of oxytocin begins with the paraventricular nucleus and supra-optic neurons in the hypothalamus express large quantities of oxytocin, which is released from the posterior pituitary gland.
A discovery in 1986 was made that oxytocin causes penile erection in male rats when injected into the brain and interacts with specific receptors (proteins) located in the cell bodies of certain neurons. These neurons may use a chemical called glutamate and contain an enzyme called NO synthase. When oxytocin binds to its receptors on these neurons, it triggers an increase in the production of a chemical called nitric oxide (NO) in these particular areas of the brain.
