Pharmacology · single question
A patient takes methotrexate and adalimumab (Humira). Which lab test is MOST important before invasive dental treatment?
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Correct answer: B. Complete blood count (CBC)
Methotrexate causes bone marrow suppression → leukopenia (infection risk), thrombocytopenia (bleeding risk), anemia. CBC is the most critical pre-operative test as it directly assesses: WBC count (infection risk), platelet count (bleeding risk), and hemoglobin. Adalimumab also causes immunosuppression, making CBC even more important.
- A. ❌ Creatinine monitors kidney function — important long-term but CBC is more immediately relevant for dental safety.
- B. ✅ CBC — directly evaluates bone marrow function; critical for assessing infection and bleeding risk pre-operatively.
- C. ❌ Bleeding time is less specific; CBC platelet count is more useful.
- D. ❌ LFTs monitor liver toxicity of methotrexate long-term — CBC is more immediately critical for dental safety.