Recent investigations have underscored the great diversity in both the causes and manifestations of clinical shock. The emphasis has shifted toward more specific therapy when that has been possible. Pure vasoconstrictors have assumed a secondary therapeutic role, as volume replacement or expansion has become the initial management of shock. Agents, such as naloxone hydrochloride, corticosteroids, fructose diphosphate, amrinone and milrinone , and nonsteroidal antiinflammatory agents, while still experimental, offer improved understanding and management of the shock syndrome.