A Comparison of Regional Intravenous Guanethidine and Reserpine in Reflex Sympathetic Dystrophy A Controlled, Randomized, Double-Blind Crossover Study

Causalgia and reflex sympathetic dystrophy: Does the sympathetic nervous system contribute to the generation of pain?

“…Five placebo-controlled studies using guanethidine IVRS have been performed. 14,65,77,133,139 Only one demonstrated a significantly better acute effect (1 h after the block). 65 One potential criticism of these guanethidine data is that four studies used only one IVRS, but multiple blocks may be necessary for treatment of RSD and causalgia.…”

“…74 Two studies showed that IVRS reserpine was ineffective. 14,139 In summary, animal studies show that, after either nerve injury or inflammation, electrical stimulation of sympathetic nerves or peripheral application of catecholamines can enhance activity in primary afferent neurons and pain behavior. In humans, activation of sympathetic neurons or application of adrenergic agonists enhances the pain in phantom limb pain, causalgia, and posttraumatic neuralgia as well as in some inflammatory pain models.…”

Treatment of complex regional pain syndrome: a review of the evidence

“…Rocco et al 29 recruited 12 patients with CRPS that presented temporary relief with either stellate or lumbar sympathetic block. IVRB was achieved using guanethidine diluted in 0.5% lidocaine, reserpine diluted in 0.5% lidocaine, or plain 0.5% lidocaine.…”

Complex regional pain syndromes

“…Five placebocontrolled studies using guanethidine IVRS have been performed [73][74][75][76][77]. Only one demonstrated a significantly better acute effect (1 hour after the block) [73].…”

“…One study demonstrated that IVRS bretylium and lidocaine produce significantly longer pain relief than lidocaine alone [79]. Two studies showed that IVRS reserpine was ineffective [74,76].…”