The patients in studies had varying degrees of ED. The combination can cause a dangerous fall in your blood pressure. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. What should I do if I forget a dose? Maximum observed plasma concentrations are reached within 30 to minutes median 60 minutes of oral dosing in the fasted state. Sildenafil treats PAH by relaxing the blood vessels in the lungs to allow blood to flow easily. Similar values for pharmacokinetic parameters were seen in normal volunteers and in the patient population, using a population pharmacokinetic approach.Most men aged 18 and over can take sildenafil for erectile dysfunction. Most adults and children aged 1 year and over can take sildenafil for pulmonary hypertension. Who may not be able to take sildenafil. Sildenafil is not suitable for some people. To make sure it’s safe for you, speak to your doctor or pharmacist before taking sildenafil if you. a light-headed feeling, like you might pass out. Common sildenafil side effects may include: flushing (warmth, redness, or tingly feeling); headache, dizziness; heartburn, nausea, or . Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in test1.ru is also used to treat pulmonary arterial hypertension, a serious heart and lung test1.ru drug is more popular than comparable drugs. It is available in generic and brand versions. Generic sildenafil is covered by most Medicare and insurance plans, but .