A report to the Council on Pharmacy and Chemistry1 in 1949 described actions of adrenolytic or sympatholytic and ganglionic blocking drugs then available. It warned that these drugs should be used with caution if at all in patients who have partial obstruction of coronary or cerebral arteries. Such obstruction often exists along with the systemic arterial changes of hypertension or peripheral vascular disease. In patients of this type cerebral or myocardial ischemia has developed with reduction of blood pressure following administration of drugs, and occasionally death has occurred.
Since that report1 several other drugs capable of blocking the efferent pathways of the sympathetic nervous system have been developed. One, hexamethonium chloride ("methium"), is an orally effective ganglionic blocking agent. Another, 1-hydrazinophthalazine hydrochloride (C-5968, "apresoline"), is a weakly adrenolytic and sympatholytic agent having several complex actions. These two drugs have been released by the Federal Food and Drug Administration
K. S. Grimson, E. S. Orgain, C. R. Rowe, H. A. Sieber. CAUTION WITH REGARD TO USE OF HEXAMETHONIUM AND "APRESOLINE". JAMA. 1952;149(3):215–220. doi:10.1001/jama.1952.02930200001001