None of the ED drugs is safe to take with cardiac drugs called nitrates because it could cause a dangerous drop in blood pressure. Drugs that many men take for urinary symptoms, called alpha blockers, can also lower blood pressure, so take them at least four hours apart from ED drugs. Your doctor may start you on a smaller dose of the ED drug if you already take an alpha blocker, or may recommend the alpha blocker tamsulosin (Flomax), which affects blood pressure less.
Ingredients: water, helianthus (sunflower) seed oil, glycine soya (soy) bean oil, stearic acid, sodium bicarbonate, citric acid, methyl salicylate, cetearyl alcohol, aloe barbadensis leaf juice, camellia sinensis (green tea) leaf extract, l-arginine, panax ginseng extract, muira puama extract, lamium album (white nettle) extract, serenoa serrulata (saw palmetto) fruit extract, lepidium meyenii (maca) root extract, erthroxylum catauba extract, rosmarinus officinallis (rosemary) leaf extract, citrus grandis (grapefruit) seed extract, lecithin, methylparaben, propylparaben, tocopheryl acetate (vitamin E), ascorbyl palmitate (vitamin C), zinc oxide, methyl nicotinate, xanthum gum, fragrance.
Both ED and low testosterone (hypogonadism) increase with age. The incidence of the latter is 40% in men aged 45 years and older.  Testosterone is known to be important in mood, cognition, vitality, bone health, and muscle and fat composition. It also plays a key role in sexual dysfunction (eg, low libido, poor erection quality, ejaculatory or orgasmic dysfunction, reduced spontaneous erections, or reduced sexual activity). 
Qaseem, A., Snow, V., Denberg, T. D., Casey, D. E., Forciea, M. A., Owens, D. K., & Shekelle, P. (2009). Hormonal testing and pharmacologic treatment of erectile dysfunction: A clinical practice guideline from the American College of Physicians. Annals of internal medicine, 151(9), 639-649. Retrieved from http://annals.org/aim/article/745155/hormonal-testing-pharmacologic-treatment-erectile-dysfunction-clinical-practice-guideline-from