[Intrathecal drugs for chronic pain control.]. / Uso de medicações por via subaracnóidea no tratamento da dor crônica.

BACKGROUND AND OBJECTIVES: Chronic pain is a challenge for modern medicine. New methods and drugs have been proposed to control pain. Intrathecal administration is a feasible and safe option, but still requires further investigations. This study aimed at reviewing available and well established drugs as well as new promising alternatives for the daily practice. CONTENTS: Several neuraxial drugs with analgesic action are reviewed. Desirable and undesirable effects of opioids, local anesthetics, alpha2-agonists, excitatory and inhibitory aminoacid antagonists, acetylcholine, acetyl-cholinesterase inhibitors, calcium channel blockers, adenosine, serotonin, tricyclic antidepressants and prostaglandin synthesis inhibitors are analyzed. CONCLUSIONS: Several advances were achieved in controlling pain with intrathecal administration of the above-mentioned drugs. Certainly some will be used, thus enriching therapeutic armamentarium, and others will be temporarily or permanently abandoned. However, several clinical and experimental studies will still be needed for knew knowledge to be incorporated and safely used by professionals dealing with chronic pain.