Electrophysiological Effects of Intravenous Clonidine on Sinus Node Function and Conduction in Man

Effect of oral clonidine premedication on PR interval in patients undergoing rhinoplasty and functional endoscopic sinus surgery (FESS)

“…Comparatively scant research has been undertaken to discern the prevalence of cardiovascular complications associated with clonidine, especially when weighed against its beneficial effects. 12 27 A 2014 study on 40 patients undergoing cataract surgeries revealed that intravenous clonidine (4 μg/kg) administered 30 min before surgery resulted in a lower prevalence of arrhythmias and a reduced myocardial attack rate compared to the placebo group. 28 A separate investigation encompassed five hypertensive cases assessed four weeks after clonidine therapy (0.2 mg/day), revealing insignificant changes in electrocardiography or echocardiography.…”

“…8 Additionally, a study focusing on patients aged ten years without a history of heart disease displayed no alterations in electrophysiological parameters, specifically atrioventricular conduction, following intravenous administration of 150 μg clonidine at varying times postadministration. 12 In tandem with the primary emphasis of this study, the investigation also explored QTc, QT, and QRS intervals. The QRS duration remained unaltered before and after clonidine administration, indicating that the preanesthetic use of oral clonidine before general anesthesia does not extend the duration of QRS.…”

“…3 Acting selectively on α2-receptors with 200 times greater affinity than α-receptors, clonidine primarily functions as an antihypertensive agent, inhibiting norepinephrine release and consequently curbing sympathetic activity and peripheral vasodilatation. [5][6][7] Apart from its hemodynamic effects, clonidine induces negative chronotropy, hypotension, 5,[8][9][10][11][12] and exhibits sedative properties through stimulation of α2-receptors in the central nervous system. [13][14] Administered orally, clonidine boasts rapid and nearly complete absorption from the gastrointestinal tract, exhibiting 100% bioavailability.…”

Anestesia peridural com lidocaína isolada ou associada à clonidina: efeito cardiorrespiratório e analgésico em cães

“…Existem controvérsias em relação ao efeito da clonidina na fisiologia cardíaca. Alguns autores relatam que a clonidina não altera o ritmo cardíaco (TOUSSAINT et al, 1984), enquanto outros sugerem que esse fármaco reduz a velocidade de condução do estímulo elétrico cardíaco (CLEMENTY et al, 1986). Dessa forma, a clonidina deve ser evitada em animais portadores de cardiopatias, pois, em pacientes predispostos, esse fármaco pode desencadear arritmias (EISENACH et al, 1989).…”