The drugs remain the main modality to achieve pharmacological management of pain . Various routes of administration for various drugs have been employed.
The quest for an ideal, suitable analgesic continues. Conventionally three classes of drugs are employed to achieve various degrees of analgesia in pharmacological management of pain :
1. Opioids:
For a long time opiods are have remained the standard for the pharmacological management of pain . Opioids have the characteristic for intense analgesia due to their effects on the opioid receptors.
Pain control by opioids needs to be considered in the context of brain circuits modulating analgesia and the functions of the various types of receptors in these circuits.
The analgesic effects of opioids arise from their ability to directly inhibit ascending transmission of nociceptive information from the spinal cord dorsal horn and to activate pain control circuits that descend from the midbrain, via the rostral ventromedial medulla (RVM), to the spinal cord dorsal horn.
2. Non-opioids
The most commonly used non opioids for pharmacological management of pain are the Nsaids or the Non steroidal Anti Inflammatory drugs.
Nonsteroidal anti-inflammatory drugs (NSAIDs), which include aspirin and acetaminophen, consist of a diverse group of analgesic compounds with different pharmacokinetic properties.
The primary mechanism by which NSAIDs exert their analgesic effect is through inhibition of cyclooxygenase (COX) and synthesis of prostaglandins, which are important mediators of peripheral sensitization and hyperalgesia.
Though traditionally viewed primarily as peripherally acting agents, NSAIDs can also exert their analgesic effects through inhibition of spinal COX.[
3. Adjuvants
Other drugs used for pharmacological management of pain are ketamine and local anesthetics.