Information Buparvaquone (Butalex) is a second-generation hydroxynaphthoquinone related to parvaquone, with novel features that make it a promising compound for the therapy and prophylaxis of all forms of theileriosis. In vivo Buparvaquone has long plasma half-life (at least 7 days) and low toxicity (oral LD50 in rats > 8000 mg/kg)