Guanethidine in Treatment of Hypertension

Purinergic Signaling and Blood Vessels in Health and Disease

“…Guanethidine was used in early times for the treatment of hypertension (Bauer et al, 1961), in retrospect inhibiting the release of both NA and ATP cotransmitters from sympathetic nerves.…”

Symptomatic sick sinus syndrome due to guanethidine. Case report.

“…While it has been suggested that bradycardia due to guanethidine causes difficulty especially in patients receiving digitalis, 8 or only in patients on digitalis, 7 our patient demonstrates that such problems may arise in the absence of digitalis therapy. We elected to control our patient on hydralazine, rather than with another of the sympatholytic drugs such as alpha-methyldopa or clonidine, which have also been shown capable of producing severe sinus node dysfunction.…”

“…On discontinuation of the digoxin, the heart rate increased to 60 bpm. Similarly, Bauer et al 8 described a patient who, while on guanethidine, was found to have an irregular pulse of 35 bpm due to sinus bradycardia with nodal escape. The patient was also receiving digoxin.…”

“…5 ' 3 More recent reports, however, have called attention to the outstanding absence of significant toxic or allergic effects attributable to guanethidine, and have also challenged the common belief that treatment of moderate hypertension with the drug is accompanied by an intolerably high incidence of side effects. 4 ' 8 Mild to moderate sinus bradycardia, not requiring drug discontinuation, has been well documented as a not infrequent side effect of guanethidine. 8 " 9 We wish to report the case of a patient receiving guanethidine who developed episodes of dizziness and blurred vision due to severe sinus bradycardia with episodes of prolonged sinus arrest.…”

“…4 ' 8 Mild to moderate sinus bradycardia, not requiring drug discontinuation, has been well documented as a not infrequent side effect of guanethidine. 8 " 9 We wish to report the case of a patient receiving guanethidine who developed episodes of dizziness and blurred vision due to severe sinus bradycardia with episodes of prolonged sinus arrest. These phenomena disappeared with discontinuation of guanethidine and reappeared upon challenge with the drug.…”