Examkin

Soru

Zorluk: OrtaMonitoring and Treatment Evaluation

A 42-year-old woman is evaluated in the clinic for a scheduled 4-week follow-up visit. One month ago, she was diagnosed with latent tuberculosis infection after a positive interferon-gamma release assay during a routine occupational health screening. She was started on a 9-month course of daily isoniazid and pyridoxine. Today, the patient reports perfect adherence to her medication regimen. She feels well and specifically denies fatigue, anorexia, nausea, vomiting, right upper quadrant pain, or dark-colored urine. She has no history of liver disease and takes no other medications. She does not consume alcohol.

Vital signs are within normal limits. Physical examination reveals anicteric sclerae and a soft, non-tender abdomen with no palpable hepatomegaly.

Laboratory studies show:
Alanine aminotransferase (ALT): 115 U/L (Reference: 7–52 U/L)
Aspartate aminotransferase (AST): 98 U/L (Reference: 10–40 U/L)
Alkaline phosphatase: 80 U/L (Reference: 40–120 U/L)
Total bilirubin: 0.9 mg/dL (Reference: 0.1–1.2 mg/dL)

Which of the following is the most appropriate next step in the management of this patient?

  1. Continue the current medication regimen and repeat liver function tests in 2 to 4 weeksCevap
  2. B
    Discontinue isoniazid and initiate rifampin monotherapy
  3. C
    Suspend isoniazid therapy and obtain an abdominal ultrasound
  4. D
    Continue isoniazid and add rifampin to shorten the treatment course
  5. E
    Discontinue isoniazid and admit the patient to the hospital for observation

Cevap

Continue the current medication regimen and repeat liver function tests in 2 to 4 weeks
The correct answer is to continue the current medication regimen and repeat liver function tests. Isoniazid commonly causes a mild, self-limited asymptomatic elevation in aminotransferases (transaminitis) in up to 20% of patients. Clinical guidelines dictate that isoniazid should only be discontinued if aminotransferase levels exceed 5 times the upper limit of normal (ULN) in an asymptomatic patient, or if they exceed 3 times the ULN in a patient experiencing symptoms of hepatotoxicity (e.g., fatigue, nausea, abdominal pain, jaundice). Because this patient is completely asymptomatic and her transaminase levels are less than 3 times the ULN, continuing the medication and providing close laboratory monitoring is the standard of care.

Adım Adım Çözüm

1
Evaluate the patient's clinical presentation and medication history.
The patient is asymptomatic and taking isoniazid for latent tuberculosis infection.
Identifying symptoms of hepatotoxicity is critical for determining the correct threshold for drug discontinuation.
2
Analyze the laboratory results against standard reference ranges.
ALT is approximately 2.2 times the upper limit of normal (ULN), and AST is approximately 2.45 times the ULN. Bilirubin and alkaline phosphatase are normal.
Calculating the magnitude of transaminase elevation directs the application of drug toxicity management guidelines.
3
Apply established guidelines for isoniazid-induced hepatotoxicity.
The criteria to stop isoniazid (elevation > 5x ULN if asymptomatic, or > 3x ULN if symptomatic) are not met.
Since the patient is asymptomatic and elevations are mild (< 3x ULN), the standard of care is to continue the medication and monitor.

Anahtar Kavram

Management of isoniazid-induced hepatotoxicity involves continuing the drug and monitoring if transaminases are elevated but remain less than 5 times the upper limit of normal in asymptomatic patients, or less than 3 times the upper limit of normal in symptomatic patients.
Tahmini Süre:1m 30s
Bu soruyu puanla

Konular

Monitoring and Treatment Evaluation

Bu konudan daha fazla soru