Current research suggests Cialis is safe to take for several years. Pulmonary arterial hypertension can develop on its own or with other cardiovascular diseases, such as left heart disease LHD , sickle cell disease SCD and its variants, chronic obstructive pulmonary disease COPD and conditions such as pulmonary embolism PE. However, the dosage can range from 25— mg. Taking tadalafil alone is not enough to cause an erection. Both Cialis and Viagra work in this way. Is Cialis safe? Nitric oxide is a substance that causes blood vessels to relax. · Cialis is available only by prescription. It’s not available over the counter. Tadalafil (Cialis) is available both as brand-name and generic tablets. Common side effects of this medication include headache and indigestion. Tadalafil (Cialis) does interact with some medications Reviewed by: Kristianne Hannemann, PharmD Connie Zheng, PharmD Last reviewed on April 11, savings_outlined GoodRx lowest price .  · information at site Informer. 线路检测中心 – 首頁欢迎您.