Pain Management Strategies

Achieving Analgesia

• Reduce nociceptor activation to alleviate pain.
• Decrease peripheral transmission to inhibit pain signaling.
• Lower cord conduction through tactile stimulation.
• Alter the perception of pain to enhance patient comfort.
• Educate patients on pain management strategies.
• Enhance descending modulation to improve pain relief.

Analgesics

• Analgesics alleviate pain without causing consciousness loss.
• Narcotic analgesics work on opioid receptors to modify pain perception and emotional response.
• Non-narcotic analgesics provide pain relief without affecting opioid receptors.
• Anti-inflammatory agents suppress inflammatory responses.

Types of Analgesics

• Steroid Agents: Chemically similar to cortisol (corticosteroids).
• Non-Steroidal Agents: Includes NSAIDs, which inhibit COX enzymes.

Narcotics and Opioids

• Opiates: Derived directly from opium, examples include morphine, codeine, and heroin.
• Opioids: Synthetic or semi-synthetic agents like oxycodone, buprenorphine, tramadol, and fentanyl.
• Opioids mimic the effects of endogenous opioids, enhancing pain relief.

Endogenous Opioid System

• Composed of widely scattered inhibitory neurons.
• Located in the PAG of the midbrain extending to the spinal dorsal horn.
• Key endogenous opioids include endorphins, enkephalins, and dynorphins.

Opioid Receptors

• Both endogenous and exogenous opioids act as agonists at these receptors.
• Agonists produce maximal receptor responses.
• Coupled to G proteins, leading to inhibitory effects on neurons.
• Reduce intracellular cAMP levels and cause K+ efflux, leading to hyperpolarization.

Mechanism of Action

• At the supraspinal level, opioids create euphoria and modify pain perception.
• Activate descending pathways to inhibit nociceptive transmission in the dorsal horn.

Advantages of Exogenous Opioids

• Effective at multiple sites within the nervous system, enhancing analgesia.

Adverse Effects of Narcotics

• Mu Receptors (MOR): Associated with analgesia and euphoria but can cause sedation, respiratory depression, bradycardia, nausea, vomiting, and constipation.
• Kappa Receptors (KOR): Provide analgesia but may lead to sedation, hypothermia, miosis, diuresis, and dysphoria.
• Delta Receptors (DOR): Associated with analgesia and potential hallucinations or constipation.

Opioid Antagonists

• Antagonists bind to receptors but do not produce a functional response, countering narcotics' effects.
• Naloxone is a prominent opioid antagonist used to reverse overdoses.

Agonist-Antagonist Combinations

• TARGIN combines oxycodone with naloxone to balance pain relief and mitigate adverse effects.

NSAIDs

• Function by inhibiting COX enzymes, specifically COX-1 and COX-2.
• COX-1 facilitates homeostasis, while COX-2 is involved in inflammation.