MFDS Human Disease and Pharmacology

Question 1

A patient with a prosthetic heart valve presents for a dental extraction. According to current NICE guidelines (2016 update), what antibiotic prophylaxis is recommended?

Accepted Answer

Antibiotic prophylaxis is NOT routinely recommended by NICE for dental procedures, even in patients with prosthetic heart valves

Answer

Amoxicillin 3g orally one hour before the procedure

Answer

Clindamycin 600mg intravenously at induction

Answer

Erythromycin 1g orally two hours before the procedure

Question 2

A diabetic patient taking metformin presents for dental treatment. Their HbA1c is 75 mmol/mol (9.0%). What is the clinical significance of this result?

Accepted Answer

The diabetes is poorly controlled (target <48 mmol/mol), indicating increased risk of delayed healing, infection, and the need for medical liaison before elective surgical procedures

Answer

The diabetes is well controlled and routine treatment can proceed without concern

Answer

The result is within the pre-diabetic range and has no relevance to dental treatment

Answer

The HbA1c indicates hypoglycaemia risk only

Question 3

What is the mechanism of action of adrenaline (epinephrine) when used in a dental local anaesthetic cartridge?

Accepted Answer

It is a sympathomimetic amine that causes local vasoconstriction via alpha-1 adrenergic receptors, reducing local anaesthetic absorption and prolonging the duration and depth of anaesthesia

Answer

It acts as a direct analgesic to enhance pain relief

Answer

It acts as an anticoagulant to reduce surgical bleeding

Answer

It directly blocks sodium channels in nerve fibres

Question 4

A patient presents for emergency dental treatment and reports taking clopidogrel and aspirin (dual antiplatelet therapy) following coronary stent insertion six months ago. How should this be managed?

Accepted Answer

Do NOT stop either drug — perform the extraction with local haemostatic measures such as suturing, oxidised cellulose, and tranexamic acid mouthwash

Answer

Stop both drugs 7 days before extraction

Answer

Stop aspirin but continue clopidogrel

Answer

Postpone all dental treatment until the antiplatelet therapy is completed

Question 5

What is the initial emergency management of anaphylaxis in the dental surgery according to the UK Resuscitation Council guidelines?

Accepted Answer

Administer intramuscular adrenaline 1:1000 (500 micrograms for an adult) into the anterolateral thigh, call 999, and position the patient supine with legs elevated

Answer

Administer oral antihistamines and observe for 30 minutes

Answer

Administer intravenous hydrocortisone only

Answer

Apply oxygen via nasal cannula and wait for the ambulance

Question 6

Which class of antihypertensive drugs is most commonly associated with drug-induced gingival enlargement?

Accepted Answer

Calcium channel blockers (e.g., nifedipine, amlodipine)

Answer

ACE inhibitors (e.g., ramipril)

Answer

Beta-blockers (e.g., atenolol)

Answer

Angiotensin II receptor blockers (e.g., losartan)