Romiplostim, sold under the brand name Nplate among others, is a fusion protein analog of thrombopoietin, a hormone that regulates platelet production.
The most common side effects in adults include headache, infections of the nose and throat, and allergic (hypersensitivity) reactions such as rash, itching and rapid swelling under the skin. The most common side effects in children include infections of the nose and throat, runny nose, cough, fever, mouth and throat pain, abdominal (belly) pain, diarrhea, rash, and bruising.