Your doctor will tell you not to take sildenafil if you are taking street drugs containing nitrates. Especially tell your healthcare provider if you take any of the following: medicines called nitrates medicines called guanylate cyclase stimulators such as Adempas riociguat medicines called alpha-blockers, such as Hytrin terazosin HCl , Flomax tamsulosin HCl , Cardura doxazosin mesylate , Minipress prazosin HCl , Uroxatral alfuzosin HCl , Jalyn dutasteride and tamsulosin HCl , or Rapaflo silodosin. The number of people who are searching for Viagra online is increasing every year. When hypertension occurs in the lungs, the heart must work harder to pump enough blood through the lungs. Before taking sildenafil, tell your doctor and pharmacist if you are allergic to sildenafil, any other medications, or any of the ingredients in sildenafil tablet or suspension. If you are taking sildenafil for erectile dysfunction, your doctor will probably start you on an average dose of sildenafil and increase or decrease your dose depending on your response to the medication. John’s wort.These cultural expectations may mask some of the true symptoms of depression. Instead, men may express aggression and anger – perceived as more acceptable “tough guy” behavior. If you are looking for a way to treat the symptoms of ED, the Sildenafil pills are your solution. Generic Viagra is effective, safe, and cheap. Buy Viagra mg online. As an alternative to Viagra, a person may wish to try any of the following: Alternative oral drugs: Including vardenafil, tadalafil, and avanafil. Nonoral drugs: Such as penile self injections.  · Maximum dose: 20 mg orally three times a day. Injection: Initial dose: or 10 mg IV bolus three times a day. Comments: No greater efficacy was achieved with oral doses higher than the maximum recommended dose. A 10 mg injection dose is predicted to provide pharmacological effect equivalent to the 20 mg oral dose.