ORE Part 1 Pain Management 3 — Questions and Answers
Question 1: What is the pharmacological basis of topical benzydamine hydrochloride (Difflam) for oral mucosal pain?
- An NSAID with local anaesthetic properties applied topically to oral mucosa — inhibits prostaglandin synthesis and has analgesic effect on inflamed mucosal surfaces (Correct answer)
- A topical antifungal agent
- An antibiotic mouthwash
- A corticosteroid applied topically
Correct answer: An NSAID with local anaesthetic properties applied topically to oral mucosa — inhibits prostaglandin synthesis and has analgesic effect on inflamed mucosal surfaces
Benzydamine (Difflam) is a topical NSAID/local analgesic mouthwash effective for painful oral mucositis (from radiotherapy, chemotherapy, or surgery) and aphthous ulcers. It inhibits prostaglandin synthesis and provides surface anaesthesia.
Question 2: What is 'allodynia' and when does it occur in dental/orofacial pain?
- Pain from a stimulus that does not normally cause pain (e.g., light touch, air, cold water causing pain in irreversible pulpitis) — indicates sensitisation of the pain pathway (Correct answer)
- Normal pain from a stimulus that always causes pain
- Pain radiating to distant sites
- Pain only occurring at night
Correct answer: Pain from a stimulus that does not normally cause pain (e.g., light touch, air, cold water causing pain in irreversible pulpitis) — indicates sensitisation of the pain pathway
Allodynia is pain elicited by normally non-painful stimuli (e.g., touch, temperature, air). It indicates sensitisation of the pain pathway (peripheral or central). In irreversible pulpitis, allodynia explains pain from non-noxious stimuli like cool water.
Question 3: What is the mechanism of paracetamol's analgesic action?
- Not fully understood — proposed mechanisms include inhibition of COX-3 in the CNS, enhancement of endocannabinoid pathways, and serotonergic modulation — predominantly central analgesic action (Correct answer)
- Inhibits peripheral COX-1 and COX-2 like ibuprofen
- Blocks sodium channels like local anaesthetics
- Opioid receptor agonism
Correct answer: Not fully understood — proposed mechanisms include inhibition of COX-3 in the CNS, enhancement of endocannabinoid pathways, and serotonergic modulation — predominantly central analgesic action
Paracetamol's precise mechanism remains incompletely understood. Unlike NSAIDs, it has minimal anti-inflammatory effect peripherally. It acts centrally, possibly via COX-3 inhibition, endocannabinoid/serotonergic modulation, and reducing descending pain facilitation.
Question 4: What is 'dry socket' (alveolar osteitis) and how is it managed?
- Painful loss of blood clot from extraction socket exposing bare bone — managed by gentle irrigation, zinc oxide eugenol/Alvogyl dressing, and analgesia (NSAIDs + paracetamol) (Correct answer)
- A post-extraction infection treated with antibiotics
- Normal post-extraction healing appearing dry
- Perforation of the maxillary sinus during extraction
Correct answer: Painful loss of blood clot from extraction socket exposing bare bone — managed by gentle irrigation, zinc oxide eugenol/Alvogyl dressing, and analgesia (NSAIDs + paracetamol)
Dry socket is painful exposure of the extraction socket bone after premature clot loss or failure, typically occurring 3–4 days post-extraction in lower molar sites. Management is palliative: socket irrigation, zinc oxide eugenol or Alvogyl dressing, and adequate analgesia.
Question 5: What is the rationale for combining paracetamol and ibuprofen for post-operative dental pain?
- They act via different mechanisms (central COX inhibition vs. peripheral prostaglandin reduction), providing additive/synergistic analgesia superior to either drug alone — multimodal approach (Correct answer)
- Only one analgesic should be used at a time to avoid toxicity
- They must be alternated, never taken together
- Ibuprofen is always sufficient alone for all dental pain
Correct answer: They act via different mechanisms (central COX inhibition vs. peripheral prostaglandin reduction), providing additive/synergistic analgesia superior to either drug alone — multimodal approach
Paracetamol (central mechanism) and ibuprofen (peripheral/anti-inflammatory) target different components of the pain pathway, providing better combined analgesia than either alone, allowing lower doses of each while reducing side effects.
Question 6: What is 'acute pulpitis' pain and how does it differ from 'irreversible pulpitis'?
- Reversible pulpitis: short, sharp pain triggered by stimuli (cold) that resolves quickly; Irreversible: spontaneous, lingering, severe pain not fully resolving after stimulus removal — indicates pulp cannot recover (Correct answer)
- Irreversible pulpitis always has visible clinical swelling
- Reversible pulpitis is always associated with visible caries
- There is no clinical distinction between the two
Correct answer: Reversible pulpitis: short, sharp pain triggered by stimuli (cold) that resolves quickly; Irreversible: spontaneous, lingering, severe pain not fully resolving after stimulus removal — indicates pulp cannot recover
Reversible pulpitis: brief, stimulus-induced pain resolving within seconds — pulp can recover. Irreversible pulpitis: spontaneous pain and/or lingering pain after stimulus removal (>30 seconds) — irreversible inflammation requiring pulp extirpation or extraction.
ORE Part 1 Pain Management 3
What is the pharmacological basis of topical benzydamine hydrochloride (Difflam) for oral mucosal pain?