N116, Pain 3 class 2025 (1)

Routes of Drug Administration

• Portal Circulation

  • Oral

  • Intravenous

  • Intramuscular

  • Rectal

  • Subcutaneous

  • Sublingual

  • Topical

  • Inhalation

  • Transdermal

  • Intrathecal

  • PCA (Patient-Controlled Analgesia)

    • 50% first-pass metabolism

    • Rapid and sustained effect

• Important Concepts

  • First-Pass Metabolism: Some routes (like oral) undergo significant metabolism in the liver before reaching systemic circulation.

  • Local Effects: Topical and intrathecal routes provide targeted effects.

Pain and Pain Treatment

• Key Considerations

  • Cause of Pain: Understand underlying issues.

  • Treatment Options: Evaluate risks vs. benefits.

  • Synergy: Use combinations for enhanced efficacy.

  • Monitoring: Efficacy and side effects.

  • Adjunct Treatments: Evaluate complementary therapies.

Synergy in Pain Treatment

• Definition: Interaction of two or more drugs resulting in a greater combined effect than the sum of their individual effects.

• Example Medications:

  • Peripheral Treatments: NSAIDs and glucocorticoids show high efficacy in inflammation.

  • CNS Treatments: Opioids are potent – assess using mg or mcg dosages.

  • Acetaminophen: Serves as an analgesic but lacks anti-inflammatory properties.

Case Study

• Patient Profile: 30-year-old with a fractured right arm, presenting acute pain.

Vital Sign Assessment

• Observations:

  • SOB: Shortness of breath assessed.

  • Skin Assessment: Significant findings noted (analyze appearance).

  • Vital Signs:

    • HR: 100 bpm

    • RR: 16

    • BP: 148/88

    • Temp: 36.8C

  • No nausea/vomiting (N&V).

Acetaminophen (Tylenol) Overview

• Use in Pain Management: First choice for various conditions due to safety in pediatrics and pregnancy.

• MOA: Acts by inducing hypothalamic-peripheral vasodilation, promoting heat loss.

• Comparative Options:

  • NSAIDs (Ibuprofen): Anti-inflammatories reducing cytokines.

  • No ASA in Pediatrics: Safety concerns with aspirin in children.

Fever Management

• Mechanisms:

  • Hypothalamic Response: Reacts to pyrogens (bacterial/endogenous).

  • Goals of Management: Comfort, decrease BMR, optimize cellular function.

    • Used medications: Acetaminophen and NSAIDs for symptomatic control.

Ingredients Caution in Combination Drugs

• Precautions: Always check drug combinations for active ingredient content:

  • Allergy-related: Antihistamines (e.g., diphenhydramine).

  • Cough: Antitussives (e.g., Codeine, Dextromethorphan) can cause CNS depression.

  • Congestion: Adrenergic agonists (e.g., Ephedrine, Pseudoephedrine) reduce nasal secretions.

Cough Reflex Overview

• Functionality: A protective mechanism involving stimulation of receptors; communicated via nervous impulses to induce the cough action.

Barriers to Pain Relief

• Challenges Identified:

  • Healthcare Professionals: Education and approach to pain management.

  • Patients: Fear of addiction impacts treatment willingness.

Understanding Addiction**

• Euphoria: Psychological aspect characterized by:

  • Cravings

  • Compulsive Use

  • Loss of Control

  • Consequences of Use

  • Reference material link provided (YouTube).

Acute vs. Chronic Pain

• Acute Pain (< 10 Days): Self-limiting, responds to treatment; SNS responses active.

• Chronic Pain (> 6 Months):

  • Often a result of poorly managed acute pain; involves neurogenic inflammation.

  • Symptoms persist, causing various dysfunctions (e.g., anxiety, insomnia).

• Management Strategies:

  • Combine treatment modalities including cognitive-behavioral therapy, physiotherapy, and CNS drugs.

  • Opioids considered but not first-line for chronic pain.

Chronic Pain Characteristics

• Influenced by repetitive SNS activity leading to chronic inflammation.

• Condition Examples:

  • CRPS (Complex Regional Pain Syndrome): Symptoms include allodynia and skin changes.

Treatment Considerations for Chronic Pain

• Underlying Diagnosis: Important in tailoring appropriate treatment plans.

• Options: Pain clinics, counseling (CBT), physiotherapy, CNS drugs targeting neurotransmitter modulation.

• Drugs of Note: Gabapentin, NMDA antagonists.