Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Side effects Side effects of oral ED medicines are often mild. Tadalafil is also used to treat men who have signs and symptoms of benign prostatic hyperplasia BPH. Doxazosin Silodosin Other Interactions Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Men with BPH usually have difficulty urinating, a decreased flow of urination, hesitation at the beginning of urination, and a need to get up at night to urinate.AdComplete the Online Consultation with our Doctor. Personalize Your Needs. If Appropriate, Get a Prescription for ED from RexMD®. Free Shipping has been visited by 10K+ users in the past monthFree Shipping · Real Doctors · Discreet Packaging · Personalized PlanTypes: Sexual Health, Testosterone, Telemedicine, Erectile Dysfunction and more. How Cialis Works. Tadalafil and other PDE5 inhibitors primarily work by inducing muscle relaxation. Tadalafil stops the breakdown of a chemical responsible for relaxing muscles. In ED and PAH, the drug targets muscle cells in blood vessels. When the blood vessel muscle cells relax, this expands the vessel and increases blood flow; this . heart attack symptoms – chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating. Common tadalafil side effects may include: headache; flushing (warmth, redness, or tingly feeling); nausea, upset stomach; stuffy nose; or. muscle pain, back pain, pain in your arms, legs, or back. This is not a complete list of side.