Examkin

Soru

Zorluk: OrtaMonitoring and Treatment Evaluation

An internal medicine physician in an ambulatory clinic is preparing to prescribe oral methotrexate for a patient with newly diagnosed, seropositive rheumatoid arthritis. The patient has no history of liver disease, hematologic abnormalities, or chronic kidney disease. Prior to dispensing the medication and establishing a follow-up schedule, the physician is formulating a comprehensive clinical and laboratory surveillance plan. Which of the following parameters are mandatory to assess at baseline and periodically during ongoing treatment with this pharmacotherapy? (Select all that apply)

  1. Complete blood countCevap
  2. Hepatic transaminasesCevap
  3. C
    Prothrombin time and international normalized ratio
  4. D
    Dual-energy x-ray absorptiometry scan
  5. E
    Thyroid-stimulating hormone

Cevap

The required parameters to monitor at baseline and periodically for a patient initiating methotrexate are a complete blood count and hepatic transaminases.
Methotrexate is an antimetabolite that competitively inhibits dihydrofolate reductase. Because it disrupts cellular replication, it preferentially affects rapidly dividing cells, making myelosuppression (resulting in leukopenia, thrombocytopenia, or megaloblastic anemia) a primary dose-limiting toxicity. Additionally, methotrexate carries a high risk of cumulative hepatotoxicity, ranging from asymptomatic transaminitis to advanced hepatic fibrosis and cirrhosis. Consequently, clinical guidelines strictly require the assessment of a complete blood count and hepatic transaminases (along with serum creatinine, as the drug is renally cleared) prior to initiation and at regular periodic intervals throughout the duration of therapy.

Adım Adım Çözüm

1
Identify the proposed pharmacotherapy and its indication.
The medication is methotrexate, prescribed as a first-line disease-modifying antirheumatic drug (DMARD) for rheumatoid arthritis.
Different DMARDs have specific and distinct adverse effect profiles requiring tailored surveillance plans.
2
Recall the mechanism of action and the primary dose-limiting toxicities of the medication.
Methotrexate acts as a folate antimetabolite. Its major adverse effects include myelosuppression, hepatotoxicity, and pulmonary toxicity.
Understanding the toxicity profile dictates the necessary laboratory parameters.
3
Select the guideline-concordant tests required to monitor for these specific toxicities.
A complete blood count is needed to detect leukopenia, anemia, or thrombocytopenia. Hepatic transaminases (AST/ALT) are needed to monitor for drug-induced liver injury.
Guidelines mandate baseline assessment and periodic re-evaluation (e.g., every 2-4 weeks initially, then every 12 weeks) of these parameters to safely maintain therapy.

Anahtar Kavram

Methotrexate is an antimetabolite DMARD that carries significant risks of bone marrow suppression and hepatotoxicity, requiring strict baseline and periodic monitoring of a complete blood count and hepatic transaminases.
Bu soruyu puanla

Konular

Monitoring and Treatment Evaluation

Bu konudan daha fazla soru