An internal medicine physician evaluates a 41-year-old male patient during a routine follo… — USMLE Step 3

An internal medicine physician evaluates a 41-year-old male patient during a routine follow-up visit. The patient reports a 4-day history of profound exhaustion, nausea without vomiting, and noticing his urine has become dark brown. Thirty days prior, he was diagnosed with active pulmonary tuberculosis and commenced on a four-drug regimen consisting of isoniazid, rifampin, pyrazinamide, and ethambutol. He does not consume alcohol and has no prior history of liver disease. Vital signs show a temperature of $37.2^\circ\text{C}$ ( $99.0^\circ\text{F}$ ), blood pressure of $118/76\text{ mmHg}$ , and heart rate of $82/\text{min}$ . Physical examination is notable for mild scleral icterus and moderate tenderness to palpation in the right upper abdominal quadrant. No hepatosplenomegaly is appreciated.

Which of the following are the most appropriate immediate steps in the management of this patient? (Select exactly two)

Withhold the entire current antituberculous medication regimenCevap
Obtain serum aminotransferases and total bilirubin levelsCevap
C
Discontinue isoniazid but continue rifampin, pyrazinamide, and ethambutol
D
Order an urgent right upper quadrant abdominal ultrasound
E
Continue the current regimen and schedule a follow-up visit in one week

Cevap

The most appropriate immediate steps are to withhold the entire current antituberculous medication regimen and to obtain serum aminotransferases and total bilirubin levels.

This patient is presenting with classic symptoms of drug-induced liver injury (DILI), a well-documented and severe adverse effect of standard first-line antituberculous therapy. When a patient on isoniazid, rifampin, and pyrazinamide develops clinical signs of hepatitis (e.g., jaundice, dark urine, abdominal tenderness, profound fatigue), standard protocol dictates that all potentially hepatotoxic medications must be stopped immediately. Simultaneously, the clinician must measure serum aminotransferases and bilirubin to quantify the severity of the hepatocellular damage. Once the liver enzymes normalize and symptoms resolve, the medications are typically reintroduced sequentially under close biochemical surveillance.

Adım Adım Çözüm

Analyze the patient's new-onset symptoms in the context of his recent medication history.

The patient has developed dark urine, scleral icterus, right upper quadrant pain, and severe fatigue exactly four weeks after initiating a four-drug regimen for active tuberculosis.

Recognizing the classic clinical presentation of symptomatic drug-induced liver injury (DILI) is essential for prioritizing immediate management.

Determine the required modifications to the patient's pharmacotherapy.

The entire antituberculous regimen must be held immediately.

Three of the four standard tuberculosis medications (isoniazid, rifampin, and pyrazinamide) are hepatotoxic. Continuing any of them during symptomatic hepatitis risks progressive liver necrosis.

Select the appropriate diagnostic tests to confirm and quantify the suspected adverse effect.

Order serum aminotransferases (AST, ALT) and total bilirubin.

Objective biochemical data is necessary to evaluate the extent of hepatocellular injury, rule out severe synthetic dysfunction, and monitor for resolution before drugs can be safely reintroduced.

Anahtar Kavram

Management of antituberculous drug-induced liver injury requires immediate cessation of all potentially offending agents and baseline evaluation of liver biochemical tests before planning sequential drug reintroduction.

Soru

Cevap

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