You are encouraged to report adverse events related to Viatris products by calling U. She works with men and couples of all ages dealing with ED and the stress, anxiety, and other underlying issues that can cause it. It comes as standard tablets, chewable tablets, and as a liquid that you swallow. Sildenafil may cause side effects. ED can be a sign of high cholesterol or diabetes. 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.Viagra Connect is the first erectile dysfunction medicine in the UK to be sold without the need for a prescription, which means you can order Viagra Connect discreetly online or . The PDE5-inhibitors available in Ireland are: Viagra (active ingredient – sildenafil) – The oldest and best known PDE-5 inhibitor. You can also buy Sildenafil as a generic. Cialis . Cialis lasts up to 36 hours in the body, while Viagra lasts 4–6 hours in the body. Both are taken 30 minutes before sex. Cialis can cause limb pain, while Viagra can cause vision change, rash.