A potentially antianginal benzo [b]thiophene with an amiodarone-like haemodynamic profile.

L 9146 or 2-methyl-3(3,5 dimethyl-4-gamma-di-n-butylaminopropoxy-benzoyl)-benzo [b] thiophene is a substance belonging to the amiodarone series which induces in the anaesthetized dog a decrease of myocardial oxygen consumption which is mainly due to slowing of the heart rate and reduction in systemic blood pressure. L 9146 also enhances coronary blood flow. L 9146 has also antiadrenergic properties since catecholamine-induced hypertension, tachycardia and increase of myocardial oxygen consumption are markedly antagonized; these antiacrenergic effects are not due to a competitive blockade of the beta-adrenoceptors. L 9146 does not decrease cardiac output, but increases it appreciably in the initial phase of its action. Several findings indicate that when the intensity of certain properties is considered, l9146 is more active than aniodarone since only half the dose used with aniodarone is required to achieve a given level of action. The overall haemodynamic properties of L 9146, which are similar to those of amiodarone, are considered to be potentially valuable for the long-term treatment of angina pectoris.