Background: Antihistamine agents are one of the most common drugs used during perioperative periods. As histamine can cause various hemodynamic reactions, administration of antihistamine can also result in unexpected responses. Therefore, we investigated what kind of hemodynamic changes might occur after the administration of antihistamine.

METHODS: We prospectively performed this study on 12 patients who underwent lung surgery. After induction of anesthesia, Swan-Ganz catheter was introduced and continuous arterial blood pressure was checked via radial arterial catheterization. Initial hemodynamic parameters were checked. Based on these parameters, we calculated systemic vascular resistance (SVR), pulmonary vascular resistance (PVR). After administration of chlorpheniramine maleate 8 mg, hemodynamic parameters were checked and calculated at 2, 4, 6, 8, 10, 12, and 15 minute. Then, we made comparisons of these values with initial values. It is commonly recommended to maintain hemodynamic values within 20% of baseline for safe use of a drug.

RESULTS: SVR and PVR failed to show statistically significant changes. Heart rates were increased only at 2 minute after administration of chlorpheniramine maleate. Blood pressures were increased but returned to basal level within 4 minutes. Cardiac output showed statistically significant increase until 8 minutes. However, the changes of hemodynamic values were maintained within 20% of basal levels.

CONCLUSIONS: Chlorpheniramine maleate is observed to cause statistically significant hemodynamic change after intravenous administration during anesthesia. But the changes were within 20% of basal levels, and we can safely use chlorpheniramine maleate 8 mg IV in the view of hemodynamic changes.