Dark Brown Urine in a Young Woman with History of Isotretinoin Use

Case at a Glance

A 21-year-old female presented with progressively darkening urine over one month, accompanied by extreme fatigue, abdominal pain, and decreased urinary frequency. Patient had recent history of isotretinoin treatment with documented elevation in liver enzymes.

Patient's Story

The patient reported that her urine had been intermittently brown for approximately one month, but became consistently dark brown after a particularly severe episode. She described the urine as remaining brown throughout the day, becoming slightly lighter with increased water intake but never returning to normal yellow color. She was drinking 1-1.5 liters of water daily (adequate for her 53kg body weight). Associated symptoms included severe fatigue despite taking stimulant medication (lisdexamfetamine 60mg daily), abdominal pain in the left lower and right upper quadrants, and markedly decreased urinary frequency (only 1-2 times per day).

Initial Assessment

Recent urinalysis performed during a 'good day' when urine appeared normal yellow showed: Protein 10 mg/dL (trace positive, previously always negative), Urobilinogen 0.2 mg/dL (detectable, previously negative), Epithelial cells <5/µL, Leukocytes <10/µL. Patient had history of isotretinoin 10mg treatment for 3 months, with liver function tests one month into treatment showing AST 46 and ALT 76 (elevated from baseline AST 17-18, ALT 10-13). Treatment was completed 4 months prior to presentation.

The Diagnostic Journey

The patient's presentation of dark brown urine with constitutional symptoms and history of hepatotoxic medication raised concern for hepatobiliary pathology. The presence of detectable urobilinogen in urine, combined with the clinical picture, suggested possible liver involvement or biliary obstruction. Differential diagnoses included drug-induced hepatotoxicity (isotretinoin), choledocholithiasis, hepatitis, or other hepatobiliary disorders.

Final Diagnosis

Pending further evaluation. Based on clinical presentation and one community member's similar experience, biliary obstruction secondary to choledocholithiasis was considered a likely diagnosis requiring urgent evaluation.

Treatment Plan

Immediate medical evaluation was recommended given the concerning constellation of symptoms. Further diagnostic workup would likely include comprehensive metabolic panel with liver function tests, complete blood count, direct and indirect bilirubin levels, and abdominal imaging (ultrasound or CT) to evaluate hepatobiliary system.

Outcome and Follow-up

Patient recognized the severity of symptoms and planned to seek immediate medical attention. Emphasized the importance of urgent evaluation given the combination of dark urine, fatigue, abdominal pain, and history of elevated liver enzymes.