If you ever need emergency medical treatment for a heart problem, the healthcare providers who treat you will need to know when you last took sildenafil. Do not take a double dose to make up for a missed one. Storage Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. This medicine usually begins to work for erectile dysfunction within 30 minutes after taking it. If too much is used, the chance of side effects is increased. · You can take the drug 30 minutes to 4 hours before you anticipate sexual activity. Based on how well you respond to this dosage and any side effects you have, your doctor may either increase your. Comprar viaja en España de forma segura LA PROVINCIA. Miles de varones buscan ofertas convenientes de genéricos de Viagra en el internet. Pero una cuestión surge .  · Viagra; Descriptions. Sildenafil is used to treat men who have erectile dysfunction (also called sexual impotence). Sildenafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. The penis is one of the areas where .