Guanfacine withdrawal

Kiechel JR, Lavene D, Guerret H Comoy E, Godin H Fillastre JP. Phaimacokinetic aspects of guanfacine withdrawal syndrome in a hypertensive patient with chronic renal failure. EurJ Clin Pharmacol (1983) 25,463-6. 

Wilson, M.F., Haring, O., Lewin, A., Bedsole, G., Srepansky, W., Fillingim, J., Hall, D., Roginsky, M., McMahon, F.G., Jagger, P., and Strauss, M. (1986) Comparison of guanfacine versus clonidine for efficacy, safety and occurrence of withdrawal syndrom in step-2 treatment of mild to moderate essential hypertension. Am J Cardiol 57 43E-49E. 

Other clinically significant differences between clonidine and guanfacine include guanfacine s longer half-life (12-23 hours, vs. clonidine s 12-16 hours) and the absence of rebound increases in blood pressure, which have been observed following abrupt withdrawal of clonidine (Wilson et ah, 1986). 

Apraclonidine Guanfacine Guanabenz Brimonidine a-methyldopa from brain to periphery resulting in decreased PVR and blood pressure Decrease nerve-evoked release of sympathetic transmitters Decrease production of aqueous humor Hypertension To reduce sympathetic response to withdrawal from narcotics, alcohol, and tobacco Glaucoma brimonidine used topically for glaucoma and ocular hypertension Methyldopa is converted in CNS to a-methyl NE, an effective agonist... 

Overall, although the frequency of troublesome adverse effects produced by guanfacine is similar to that produced by clonidine and the other centrally acting sympatholytics, their incidence and severity are lower with guanfacine. Unlike clonidine, abrupt discontinuation of guanfacine rarely results in rebound hypertension. When a withdrawal syndrome has occurred, its onset was slower and its symptoms less severe than the syndrome observed with clonidine. 

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