Sildenafil may cause side effects. If you are taking sildenafil to treat erectile dysfunction, follow your doctor’s directions and the guidelines in this paragraph. What side effects can this medication cause? If you experience chest pain, dizziness, or nausea during sex, seek immediate medical help. Sildenafil Liqrev, Revatio is used to improve the ability to exercise in adults Liqrev, Revatio and children 1 year of age and older Revatio with pulmonary arterial hypertension PAH; high blood pressure in the vessels carrying blood to the lungs, causing shortness of breath, dizziness, and tiredness. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Sildenafil works on the PDE5 enzyme in the lungs to relax the blood vessels.Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Sildenafil (Liqrev, Revatio) is used to improve the ability to exercise in adults (Liqrev, Revatio) and children 1 year of age and older (Revatio) with pulmonary arterial hypertension (PAH; high blood pressure in the vessels carrying blood to the . The price of brand name Cialis can range from $12 to upwards of $70 per tablet, depending on the specific dosage of the medication. For a month’s supply, typical pricing ranges from $ to $1, or more. Cialis comes in tablet form and is available in several doses, ranging from mg all the way up to 20mg. The generic version of Viagra, sildenafil works in the same way for a much lower price per dose. It comes in 25, 50, and mg options starting at $4 per dose. Hims also recommends sildenafil for PE.