ORE Part 1 Pharmacology 2 — Questions and Answers
Question 1: Which drug should be available in every UK dental practice for the management of anaphylaxis?
- Hydrocortisone
- Chlorphenamine
- Adrenaline (epinephrine) (Correct answer)
- Salbutamol
Correct answer: Adrenaline (epinephrine)
Adrenaline (epinephrine) 1:1000 for intramuscular injection is the most critical drug in anaphylaxis management and must be available in every dental practice as per Resuscitation Council (UK) guidelines. While hydrocortisone and chlorphenamine are adjunctive treatments, adrenaline is the life-saving first-line drug.
Question 2: What is the primary mechanism by which amoxicillin exerts its antibacterial effect?
- Inhibition of protein synthesis at the 30S ribosomal subunit
- Inhibition of bacterial cell wall synthesis by binding to penicillin-binding proteins (Correct answer)
- Inhibition of DNA gyrase
- Disruption of the bacterial cell membrane
Correct answer: Inhibition of bacterial cell wall synthesis by binding to penicillin-binding proteins
Amoxicillin, like all beta-lactam antibiotics, works by binding to penicillin-binding proteins (PBPs) and inhibiting transpeptidation, the final step in bacterial cell wall (peptidoglycan) synthesis. This leads to cell lysis, particularly of actively dividing bacteria, making it bactericidal.
Question 3: A patient taking the direct oral anticoagulant (DOAC) apixaban attends for extraction. What is the current SDCEP advice?
- Stop the DOAC 48 hours before extraction
- Continue the DOAC and use local haemostatic measures (Correct answer)
- Switch to warfarin before extraction
- Only extract under general anaesthetic in hospital
Correct answer: Continue the DOAC and use local haemostatic measures
SDCEP guidance recommends that patients on DOACs (apixaban, rivarelbant, dabigatran, edoxaban) should continue their medication for dental extractions. Local haemostatic measures (sutures, oxidised cellulose, tranexamic acid) should be used. For procedures with higher bleeding risk, timing the appointment to coincide with trough drug levels is advised.
Question 4: Which drug is used as a reversal agent for benzodiazepine sedation in dentistry?
- Naloxone
- Flumazenil (Correct answer)
- Atropine
- Neostigmine
Correct answer: Flumazenil
Flumazenil is a competitive antagonist at the benzodiazepine binding site on the GABA-A receptor. It is used to reverse benzodiazepine sedation (midazolam) in emergency situations. However, its duration of action is shorter than midazolam, so re-sedation can occur and the patient must be monitored.
Question 5: What is the recommended first-line analgesic regimen following dental extraction in an adult with no contraindications?
- Codeine 60mg four times daily
- Ibuprofen 400mg and paracetamol 1g taken together (Correct answer)
- Aspirin 600mg four times daily
- Diclofenac 50mg three times daily alone
Correct answer: Ibuprofen 400mg and paracetamol 1g taken together
The combination of ibuprofen 400mg and paracetamol 1g provides superior analgesia to either drug alone through synergistic action on different pain pathways. This combination is now recommended as first-line post-extraction analgesia in UK dental practice guidelines, avoiding the side effects of opioid-based alternatives.
Question 6: Chlorhexidine gluconate mouthwash should not be used immediately after which toothpaste ingredient?
- Fluoride
- Sodium lauryl sulphate (SLS) (Correct answer)
- Calcium carbonate
- Triclosan
Correct answer: Sodium lauryl sulphate (SLS)
Sodium lauryl sulphate (SLS), the foaming agent in most toothpastes, is an anionic surfactant that interacts with the cationic chlorhexidine molecule, inactivating it. Patients should wait at least 30 minutes after brushing before using chlorhexidine mouthwash, or use an SLS-free toothpaste.
ORE Part 1 Pharmacology 2
Which drug should be available in every UK dental practice for the management of anaphylaxis?