Examkin

Question

Difficulty: MediumMonitoring and Treatment Evaluation

A 54-year-old man is diagnosed with moderate-to-severe rheumatoid arthritis following an extensive evaluation for symmetric small joint pain and prolonged morning stiffness. His rheumatologist initiates disease-modifying treatment with weekly oral methotrexate and daily folic acid supplementation. The patient has a past medical history of essential hypertension, which is well-controlled with amlodipine. He is a non-smoker and does not consume alcohol. Baseline laboratory studies, including a comprehensive metabolic panel, complete blood count, hepatitis serologies, and a chest radiograph, were all within normal limits prior to starting the new medication.

Which of the following parameters are required for routine, ongoing monitoring of this patient's new pharmacotherapy? (Select all that apply)

  1. Complete blood countAnswer
  2. Hepatic transaminasesAnswer
  3. C
    Pulmonary function tests
  4. D
    Ophthalmologic examination
  5. E
    Serum uric acid

Answer

The correct parameters for routine monitoring of methotrexate therapy are a complete blood count and hepatic transaminases.
Methotrexate is a folate antimetabolite that competitively inhibits dihydrofolate reductase. Because it targets rapidly dividing cells, it frequently causes dose-dependent myelosuppression (leukopenia, thrombocytopenia, macrocytic anemia) and hepatotoxicity. Consequently, the standard of care requires routine periodic monitoring of a complete blood count and hepatic transaminases. Renal function (serum creatinine) must also be routinely monitored because the drug is primarily cleared by the kidneys, and declining renal function significantly increases the risk of systemic toxicity.

Step-by-Step Solution

1
Identify the prescribed high-risk medication and its common organ toxicities.
The patient was started on methotrexate, an antimetabolite known to cause bone marrow suppression, hepatotoxicity, and mucosal irritation.
Recognizing the side effect profile is necessary to determine what organ systems require active surveillance.
2
Determine the standard guideline-concordant tests required for ongoing surveillance.
Standard clinical guidelines mandate regular monitoring of a complete blood count, hepatic transaminases, and serum creatinine.
These tests detect subclinical myelosuppression and liver injury before irreversible damage occurs.
3
Rule out tests that belong to different medications or diseases.
Ophthalmologic exams are for hydroxychloroquine, uric acid is for gout, and pulmonary function tests are only indicated if symptoms of pneumonitis develop.
Avoids the application of unnecessary or incorrect monitoring protocols.

Key Concept

Patients on methotrexate therapy require ongoing, routine laboratory monitoring of their complete blood count, hepatic transaminases, and serum creatinine to safely detect drug-induced myelosuppression and hepatotoxicity.
Rate this question

Topics

Monitoring and Treatment Evaluation

More questions from this topic