Published on October 18, warning This article is no longer being updated and some information may not be current. Visit the GoodRx Healthhomepage for our latest articles. We have good news for you: generic Cialis, used to treat erectile dysfunction (ED)and .Tadalafil can be synthesized starting from D – tryptophan methyl ester and piperonal via a Pictet—Spengler reaction. Severe liver disease. Tadalafil was approved in in the United States for the treatment of pulmonary arterial hypertension [28] and is under regulatory review in other regions for this condition. If you ever need emergency medical treatment for a heart problem, the health care providers who treat you will need to know when you last took tadalafil. An inherited eye disease that affects the retina.Tadalafil is a medicine used to treat erectile dysfunction (ED, also called impotence) and problems with urination caused by an enlarged prostate (benign prostatic hypertrophy or BPH). It is sometimes known by its generic name tadalafil, and sometimes known by its trade name, Cialis. There are also other brands of this medicine available. Cialis is only available by prescription in the United States. Viagra: Additionally, a study from Trusted Source. found that combining L-arginine and sildenafil (Viagra) worked better for. The four main medicines taken by mouth for erectile dysfunction are: Avanafil (Stendra). Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes muscles in the penis, called nitric oxide.If you become pregnant while taking tadalafil, call your doctor. In trials investigating Cialis, the majority of participants receiving the drug experienced a significant improvement in ED and maintained an erection. These small differences affect the way each medication works, such as how quickly it takes effect and wears off, and the possible side effects. Cialis and Viagra are equally effective. They are PDE5 inhibitors that allow for increased blood flow to the penis, leading to more frequent and harder erections. Persons surnamed “Cialis” objected to Eli Lilly and Company’s so naming the drug, but the company has maintained that the drug’s trade name is unrelated to the surname. Generic versions of sildenafil, vardenafil and tadalafil are available.