yī / shēng / gěi / tā / kāi / le / kàng / níng / xuè / jì / yǐ / fáng / zhǐ / xuè / shuān / xíng / chéng

医生给他开了抗凝血剂，以防止血栓形成。

The doctor prescribed him an anticoagulant to prevent blood clots from forming.