Antipyretics & Analgesics: Summary

Definitions

• Analgesic:
  • From Greek words "an" (without) and "algos" (pain).
  • Categorized into non-opioids, opioids, and adjuvant analgesics.
• Antipyretic:
  • From Greek "anti" (against), Latin "pyreticus," and Greek "puretos" (fire/fever).

WHO Analgesic Ladder

• Steps:
  • Step 1: Mild pain; non-pharmacological approaches, paracetamol.
  • Step 2: Moderate pain; NSAID and/or oral opioid.
  • Step 3: Severe pain; increased dose of an oral opioid or IV/SC opioid or IN fentanyl.
• Advantages:
  • Good for short-term management of acute pain.
  • Simple, safe (lowest dose first), emphasizes drug combinations.
• Disadvantages:
  • Too simplistic for chronic pain, lacks guidance on formulations.
  • Opioids have adverse effects; may not suit all patients.
  • Pain management should be individualized.

Paracetamol (Acetaminophen)

• Trade Names: Panadol, Tylenol, Panamax, Dymadon
• Mechanism of Action: Inhibits peroxidase, preventing COX activation.
• Indications: Fever, mild-to-moderate pain.
• Side Effects/Adverse Effects:
  • Overdose can cause severe liver injury, increased by fasting/alcohol use.
• Nursing Considerations:
  • Caution with liver disease; overdose treatment within 10 hours.
  • Soluble preparations contain sodium.
  • Not for infants under 1 month.

Ibuprofen

• Class: Non-steroidal anti-inflammatory drug (NSAID)
• Trade Names: Neurofen, Advil, Motrin, Caldolor
• Mechanism of Action: Inhibits prostaglandin synthesis by inhibiting cyclo-oxygenase (COX).
• Indications: Pain (especially inflammation/tissue injury), fever.
• Side Effects/Adverse Effects:
  • Nausea, dyspepsia, GI ulceration/bleeding, raised liver enzymes.
• Nursing Considerations:
  • Take with food to prevent GI irritation.
  • Assess for allergies, asthma, gastric issues before starting.
  • Monitor for bleeding if administered preoperatively.
  • Contraindicated in peptic/GI ulceration, bleeding disorders, severe liver/kidney/cardiac failure, post-CABG.

Morphine

• Class: Opioid analgesic
• Trade Names: Morphine sulfate, Zomorph, Sevredol, Morphgesic, MXL, Oramorph
• Mechanism of Action: Acts at mu-opioid receptors in the CNS.
• Indications: Severe pain.
• Side Effects/Adverse Effects:
  • Nausea/vomiting, drowsiness, dizziness, constipation, respiratory depression.
• Nursing Considerations:
  • Ensure correct strength is selected.
  • Rotate injection sites.
  • Monitor respiratory function.
  • Chronic use may lead to tolerance/dependence.