Romiplostim is a fusion protein analog of thrombopoietin, a hormone that regulates platelet production.romiplostim is indicated as a potential treatment for chronic idiopathic (immune) thrombocytopenic purpura (itp).romiplostim treatment is generally administered at weekly intervals via subcutaneous injection. prior to injection, a complete blood count (cbc) is obtained, as the dosage is dependent on the individual s body weight and platelet count at the time of treatment.