Estramin 140mg Capsule is used to treat prostate cancer. It contains Estramustine, an antimicrotubule agent that works by blocking DNA replication (genetic material) in cancer cells. Hence, this stops the further growth and multiplication of the cancer cells. Common side effects of Estramin 140mg Capsule may include nausea, dizziness, heartburn, headache, diarrhoea, muscle weakness, joint pain, hot flushes, nausea, vomiting, thirst, flatulence, edema, and GI bleeding.