Pharmacology, Anesthesia and Pain Control
What the exam tests
This domain tests safe local anesthesia, analgesic and antibiotic prescribing, and sedation principles. The exam expects dose calculation, recognition of contraindications and evidence-based prescribing.
Core rules and concepts
- Local anesthetics: lidocaine 2% with epinephrine 1:100,000 is standard; the maximum recommended dose is about 4.4 mg/kg (often capped at 300 mg). Articaine 4% is used for infiltration and block anesthesia; bupivacaine is long-acting. Calculate milligrams, not milliliters.
- Vasoconstrictors: epinephrine improves depth and hemostasis; use cautiously in uncontrolled hyperthyroidism, pheochromocytoma and severe cardiovascular disease, and know the interaction with tricyclic antidepressants.
- Techniques: inferior alveolar nerve block, Gow-Gates and infiltration have different success and complication profiles; aspiration reduces intravascular injection.
- Analgesia: NSAIDs or paracetamol for odontogenic pain; avoid opioids for routine dental pain. Do not prescribe antibiotics for irreversible pulpitis or uncomplicated abscess without systemic involvement.
- Antibiotics: amoxicillin is first-line; use clindamycin or another appropriate agent in true penicillin allergy. Reserve antibiotics for spreading infection or systemic signs.
- Sedation: midazolam requires monitoring, oxygen and rescue equipment; capnography and pulse oximetry improve safety.
Worked example
A 60 kg patient needs a mandibular block. Reasoning: lidocaine 2% contains 20 mg/mL; at 4.4 mg/kg the limit is 264 mg, or about 13 mL. A standard block uses 1.5–2 mL, well within the limit; still aspirate and monitor for intravascular injection.
Traps
Exceeding the maximum dose by counting cartridges loosely; prescribing antibiotics for pulpitis; confusing ester and amide allergy; ignoring epinephrine contraindications; sedating without monitoring.