Viagra (Sildenafil citrate) by Pfizer, Inc. is a selective phosphodiesterase-5 (PDE5) inhibitor used as a 1st- or 2nd-line treatment in patients presenting with scleroderma secondary to pulmonary arterial hypertension. Most of these patients suffer from a severe condition called Raynauds phenomenon, and around half of the patients show fingertip ulcerations, despite chronic intake of calcium channel blockers. Selective PDE5 inhibitors have been studied for the management of severe Raynauds phenomenon in 2006.
There are a several case reports in which the researchers tested köp viagra in the treatment of cutaneous fingertip ulcerations in patients with secondary Raynauds phenomenon,2 and a current double-blinded, randomized trial exhibited significant benefits to the patients.
Nitrates have been known for years as one of the standard treatments for Raynauds phenomenon.
However; systemic nitrates shows common side effects related to their ability as blood vessel dilators or vasodilators. Recent researches have observed that a novel topical nitroglycerin medication may reduce the severity of Raynauds phenomenon,5 establishing the probable interest in local management of nitrates. Iontophoresis, a transdermal drug using a low-intensity electric current, could be an interesting alternative to skin ointments. Indeed, iontophoresis of sodium nitroprusside (SNP) shows a non-neurologic-dependent, amplified cutaneous vascular conductance (CVC) on the arms of patients with 2° Raynauds phenomenon.
Moreover, some researchers recommend that there is are promising results in blood vessel dilators as a mode of treatment for digital ulcerations.
Certainly, this type of drugs may be of medical and therapeutic value with less systemic adverse effects.
Viagra (Sildenafil) is a selective PDE5 inhibitor which reduces the metabolism of cyclic guanosine monophosphate or cGMP. The activity of endothelial nitric oxide (NO) via the cGMP pathway is amplified and leads to enhanced blood vessel dilation. SNP donates NO in the body, which activates guanylate cyclase and increased levels of cGMP in smooth muscle cells. The resultant blood vessel dilation is thus not affecting the endothelial production of NO. Thus, selective PDE5 inhibitors such as Viagra and nitrates have a synergistic drug interaction, and when both taken regularly, it can significantly decrease blood pressure in comparison to nitrates alone.
As a concern, the drug combination of nitrates and Viagra is not advised due to a probable sustained arterial hypotension.
The drug combination of orally administered-selective PDE5 inhibitors with the local intake of a short half-life nitrate, iontophoresis, could theoretically decrease the systemic adverse effects while activating local microvascular blood circulation. In a clinical trial done in 10 healthy volunteers in 2010 and analyzed using laser Doppler imaging, Viagra taken at a dose 100 mg, but not 50 mg, had been found to potentiate localized increased skin blood flow or skin hyperemia induced by iontophoresis, with no amplified occurrences of headaches. SNP iontophoresis was done on the ventral skin surface of the forearm, 1 hour after the application of lidocaine/prilocaine (1:1) cream, covering around 1 cm2 of the skin surface initially. The combination therapy of cialis 20mg pris and nitrates administered through SNP iontophoresis warrants further investigation for the treatment of certain diseases such as severe Raynauds phenomenon, with specific focus to the condition of arterial hypotension.