β2致效劑（β2 agonist; β2作用劑）原本是用來治療氣喘的藥物，長期且大量服用有增加肌肉質量及降低脂肪的效果，尤其是促進快縮肌之生長，因此被許多運動員拿來濫用，以期能增進運動表現，然而其副作用及濫用所造成的嚴重後遺症，使得IOC將之列為運動禁藥。最新的IOC規定，係將同化性物質分為兩類：男性同化性類固醇（androgenic anabolic steroids）及β2致效劑（β2 agonist）。運動員開始使用同化性類固醇是在五十年代早期。當時蘇聯就有使用類固醇的報導。同化性類固醇在1976年蒙特婁奧運體中第一次被列在禁藥名單中，β2致效劑則於1992年7月明訂禁止使用。本文對β2致效劑做深入之探討，同時並介紹國內上市之β2致效劑，以防運動員之誤用。 β2 agonist is used as a bronchodilator and carries an indication for bronchial asthma. When administered in doses far greater than those required for bronchodilation chronically, it increased the rate of muscle protein deposition and promoted lipolysis. It had a greater growth promoting effect in fast twitch fibers than slow twitch fibers. And it is a recently popular drug used by athletes in many sports for its purported anabolic effects and reduction of subcutaneous fat. IOC listed it on the banned substance because of its serous side effects. The purpose of this article is to understand β2 agonist accurately, and preventing athletes misusing incautiously.
