Pharmacology · single question
A patient is taking Methotrexate and Humira (adalimumab) for rheumatoid arthritis. What laboratory test is most important to monitor before dental treatment?
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Correct answer: A. Creatinine (renal function)
Methotrexate is primarily renally excreted and is nephrotoxic at higher doses. Creatinine and GFR must be monitored because renal impairment causes methotrexate accumulation, leading to severe toxicity (mucositis, myelosuppression). Additionally, both methotrexate and adalimumab are hepatotoxic and immunosuppressive. CBC (for myelosuppression) and LFTs are also monitored. The source specifically cited creatinine.
- A. CORRECT. Creatinine/GFR monitoring is critical because methotrexate is renally cleared — impaired kidneys cause drug accumulation and life-threatening toxicity.
- B. Incorrect. INR is monitored for warfarin therapy. Methotrexate/Humira do not primarily affect the coagulation cascade.
- C. Incorrect. Fasting glucose is relevant for corticosteroids and diabetic patients, not specifically for methotrexate/adalimumab therapy.
- D. Incorrect. Serum calcium monitoring is not associated with methotrexate or adalimumab therapy.