PROBLEM To provide a therapeutic agent for cardiac tamponade to suppress occurrence of complications accompanying cardiac tamponade by preventing and improving deterioration of macro- and micro-circulation caused by cardiac tamponade and also by suppressing local and systemic inflammation accompanying such deterioration of circulation. SOLUTION A pharmaceutical which contains a peptide of the present invention or a pharmaceutically acceptable salt of such peptide as an active ingredient is useful as a therapeutic agent for cardiac tamponade (pericardial tamponade) caused by myocardial infarction, malignant tumor metastasis, collagen disease, or the like.