Satismax is a phosphodiesterase inhibitor. It works in erectile dysfunction by increasing blood flow to the penis by relaxing the muscles in penile blood vessels. It works in pulmonary hypertension by relaxing the blood vessels in the lungs to allow blood to flow more easily.Dapoxetine is a selective serotonin reuptake inhibitor antidepressant. It works by increasing the level of serotonin in nerve thereby increasing the time it takes to ejaculate and can improve the control over ejaculation.