Guanadrel
Guanadrel is a spiroketal resulting from the formal condensation of the keto group of cyclohexanone with the hydroxy groups of 1-(2,3-dihydroxypropyl)guanidine. A postganglionic adrenergic blocking agent formerly used (generally as the sulfate salt) for the management of hypertension, it has been largely superseded by other drugs less likely to cause orthostatic hypotension (dizzy spells on standing up or stretching). It has a role as an antihypertensive agent and an adrenergic antagonist. It is a member of guanidines and a spiroketal. It is a conjugate base of a guanadrel(1+).