Pharmacology and Therapeutics in Oral Medicine
Domain 7 tests drug selection, dosing, monitoring, and interactions for the medications used in oral medicine. The exam favors questions about topical versus systemic corticosteroids, antifungal choice, antiviral timing, and safe prescribing in pregnancy and organ disease.
Topical therapy
- Triamcinolone acetonide 0.1% paste, fluocinonide 0.05% gel, and clobetasol 0.05% are used for oral lichen planus, aphthae, and mucous membrane pemphigoid.
- Side effects include candidiasis, mucosal atrophy, and adrenal suppression with high-potency agents over large areas.
- Antifungals include nystatin, clotrimazole, fluconazole, and itraconazole; azoles interact with CYP3A4 substrates such as warfarin and statins.
- Topical anesthetics such as lidocaine viscous and benzocaine provide short-term relief.
Systemic therapy
- Prednisone is used at 0.5 to 1 mg/kg with a taper; monitor glucose, blood pressure, infection, and bone health.
- Antivirals include acyclovir, valacyclovir, and famciclovir; start within 72 hours of herpes zoster or severe herpes simplex.
- Antibiotics include amoxicillin, metronidazole, and clindamycin; use only for bacterial infection and follow stewardship principles.
- Immunosuppressants such as azathioprine, mycophenolate, and methotrexate require monitoring.
- Bisphosphonates and denosumab are associated with medication-related osteonecrosis of the jaw.
Special populations
- Pregnancy: avoid tetracyclines and high-dose fluconazole; assess risk and benefit.
- Renal or hepatic impairment: adjust doses and avoid nephrotoxic or hepatotoxic drugs.
- Older adults: review polypharmacy and interactions.
Worked example
A 50-year-old woman with erosive oral lichen planus does not respond to topical triamcinolone. Confirm the diagnosis by biopsy, check for candidiasis, and review for a lichenoid drug. Escalate to fluocinonide gel; if still uncontrolled, use a short systemic prednisone taper with glucose monitoring and a taper plan.
Traps that cost marks
- Starting systemic corticosteroids without a taper or monitoring.
- Missing azole and warfarin or statin interactions.
- Applying a topical steroid to unrecognized candidiasis.
- Prescribing antibiotics for viral or aphthous ulcers.
- Failing to check pregnancy status before prescribing.