Natriuretic and water diuretic effects of guanabenz, a central alpha-2 agonist.

I should like to preface my concluding remarks by noting that our observations are still of a preliminary nature. Guanabenz, an acute central adrenergic inhibitor produces in human subjects (previously volume expanded with saline) changes similar to those previously described in animals, namely a rise or no change in GFR, an enhancement of water diuresis, and a significant natriuresis. Within one week of the acute study and during chronic administration of guanabenz, all of these changes were reversed: GFR, the magnitude of the water diuresis and the enhanced sodium excretion had returned to the baseline pre-guanabenz levels, indicating that certain adaptive, restorative mechanism were operative. One may conclude, however, that the potential natriuretic properties of guanabenz (even during chronic administration), counter-balance the sodium retaining side effects commonly seen with other centrally acting and vasodilating antihypertensive drugs. This property, therefore, makes this agent a scientifically interesting and potentially useful therapeutic drug in the treatment of high blood pressure.