Please tell me, could edex be used combination viagra (sildenafil) successfully or can they only be used separately?

Edex (alprostadil): Edex or any injectable agent can be used with an oral agent such as Viagra (sildenafil). You should consult with your urology which doses are the best

Here are some ...: For on-label use, they should be used separately; for off-label, they can be used together under professional guidance with proper patient-physician collaboration. So, ask your treating Doc for individual advice timely before trying both at the same time. Best wish ...