Ecolid: a new hypotensive agent.

During the past five years ganglion-blocking agents have been used extensively in the treatment of arterial hypertension. The discovery of the activity of hexamethonium by Paton and Zaimis (1949) placed at our disposal an active therapeutic agent capable of producing a substantial reduction in the blood pressure. Subsequent research has been directed to the synthesis of new drugs offering advantages over hexamethonium. In the treatment of hypertension, it is desirable to obtain a sustained fall in the blood pressure by the oral administration of a drug producing a minimum of sideeffects. Hexamethonium is inconstant in action by mouth, its duration of action is short, and it produces side-effects characteristic of generalized ganglionic blockade. Maxwell and Campbell (1953) examined a number of methonium homologues and indicated the suitability of one of them, pentolinium, for therapeutic application. At present pentolinium is the most active hypotensive drug available and it has been widely employed. Trapold et al. (1955) have described the pharmacological actions of a new synthetic compound. " ecolid " (SU-3088), and Grimson et al. (1955) have demonstrated its activity in lowering the blood pressure in man. Trapold et al. (1955) have described a series of halogenated isoindolines with potent ganglion-blocking activity of long duration. Ecolid was the most active compound investigated. It is 4,5,6,7-tetrachloro-2-(2-dimethyl-aminoethyl)isoindoline dimethochloride, the structural formula being as follows: Cl CH3