Complex Regional Pain Syndrome Type 1 (Reflex Sympathetic Dystrophy) Medication

Updated: Mar 09, 2021
  • Author: T P Sudha Rao, MD; Chief Editor: Herbert S Diamond, MD  more...
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Medication Summary

Several drugs, either alone or in combination with sympathetic blockade, may be efficacious in prolonging the duration of symptomatic relief. Some of these drugs reduce the activity of the sympathetic nervous system, whereas others are primarily anti-inflammatory.



Class Summary

These medications reduce the activity of the sympathetic nervous system.

Clonidine (Catapres)

Stimulates alpha2-adrenoreceptors in brain stem, activating an inhibitory neuron, which in turn results in reduced sympathetic outflow. These effects result in a decrease in vasomotor tone and heart rate.

Phenoxybenzamine (Dibenzyline)

Produces a long-lasting blockade of alpha-adrenergic receptors in smooth muscle and exocrine glands. Blocks epinephrine-induced and norepinephrine-induced vasoconstriction.

Prazosin (Minipress)

Dilates both arteries and veins by blocking postsynaptic alpha1-adrenergic receptors.


Anti-inflammatory agents

Class Summary

Although little evidence exists for systemic inflammation in reflex sympathetic dystrophy (RSD), prominent local inflammation with pain, tenderness, swelling, redness, and loss of function is present.

Prednisone (Deltasone, Meticorten, Orasone)

May decrease inflammation by reversing increased capillary permeability and suppressing PMN activity.


Endocrine agents

Class Summary

These agents may inhibit osteoclastic bone resorption.

Calcitonin (Miacalcin, Osteocalcin)

Lowers elevated serum calcium levels in patients with multiple myeloma, carcinoma, or primary hyperparathyroidism. Can expect a higher response when serum calcium levels are high. Onset of action is approximately 2 h following injection, and activity lasts for 6-8 h. May lower calcium levels for 5-8 d by about 9% if administered q12h. IM route is preferred at multiple injection sites with dose >2 mL. It can also be administered via intranasal spray.

Calcitonin is also an effective agent to treat metabolic bone disease such as osteoporosis. Through some unknown mechanism, it appears to have an analgesic effect on bone pain, such as occurs with osteoporotic vertebral collapse. The mechanism by which calcitonin relieves the symptoms of RSD is unknown.