重症心不全に対するIbopamine hydrochlorideの急性効果—血行動態，血漿catecholamine，renin activity，aldosterone，代謝および血液gasによる検討

Acute effects of ibopamine hydrochloride on hemodynamics, plasma catecholamine levels, renin activity, aldosterone, metabolism and blood gas in patients with severe congestive heart failure

　重症あるいは難治性心不全の治療としての血管拡張剤，catecholamine製剤の有効性が種々報告されており，とくにdopamine，dobutamineは心原性shockや重症心不全に対する効果が脚光を浴びているが，体内で速やかに代謝されるため経口投与で効果が認められないとされている^1〜14）。

　Dapamineと類似の構造をもち，腎血管拡張作用を持つcatecholamineとしてepinine，すなわちN-metyldopamineはよく知られている^15,16）。

Acute hemodynamic and metabolic effects of oral 200mg ibopamine hydrochloride, which is a new diisobutyric ester of N-methyl dopamine, were evaluated in 11 patients with congestive heart failure (NYHA IV°).

Effects occurred within 30 min and persisted sig-nificantly for 6hrs after administration. Peak effects was observed at 2hrs after administration. At the peak effects, CI increased from 2.53l/min/m2 to 3. 07l/min/m² (+20%, <0.01), SVI 35ml/beat/m² to 41mi/beat/m² (+18%, <0.05), SWI 35gm･m/deat/m² to 44gm･m/beat/m² (+26%, <0.05), epinephrine 0.05 ng/ml to 0.15ng/ml (+200%, <0.05), urine volume 50ml/hr to 81ml/hr (+61%, <0.05) and PCWP dec-reased from 23mmHg to 18mmHg (-24%, <0.001), PAm 33mmHg to 27mmHg (-19%, <0.001), RA 10 mmHg to 7mmHg (-27%, <0.001), SVR 1735dyn･ sec･cm^-5 to 1546dyn･sec･cmp^-5 (-11%, <0.1), PVR 204 dyn･sec･cm^-5 to 168dyn･seccm-5(-25 %, <0.05), A-VO2 6.09ml/dl to 5.36ml/dl (-12%, <0.05), norepinephrine 0.45ng/ml to 0.34ng/ml (-24%, <0.1), renin activity 1.80ng/ml/hr to 1.26ng/ ml/hr (-30%, <0.05), respectively, whereas there was no significant change in the other blood gas data, heart rate, blood pressure, double product, al-dosterone, urine, K⁺ and lactate/pyruvate.

Therefore, ibopamine seems to have not only a positive inotropic action but also a potent vasodi-lating action, leading to both afterload and preload reduction, and so to be useful for the treatment of severe congestive heart failure.