Licensed Pharmacy Viagra canadian pharmacy viagra Sildenafil should be used cautiously in men on alpha blockers such as doxazosin (Cardura), terazosin (Hytrin), and tamsulosin (Flomax). There have been occasional reports of low blood pressure in men who have taken the two classes of drugs simultaneously and therefore it is recommended that there be at least a span of 4-6 hours between the ingestion of sildenafil and alpha blockers. Erectile dysfunction. Two rigid cylinders have been placed into the corpora cavernosa. This type of implant has no inflation mechanism but provides adequate rigidity to the penis to allow penetration. Conclusion Dramatic advances in the management of erectile dysfunction have occurred over the past decade. Most patients with the condition are now managed by primary care physicians and specialists other than urologists. A thorough clinical examination can help to differentiate from the numerous causes of erectile dysfunction. Oral therapy with a PDE-5 inhibitor (sildenafil, vardenafil or tadalafil) should be considered for first-line treatment of erectile dysfunction. Although PDE-5 inhibitors should not be given to patients taking nitrates, because of the risk of hypotension, in general they are well tolerated by the majority of patients. Those who do not respond to this first-line therapy should be referred to a urologist for further evaluation and consideration of alternative treatments.