Green urine is a distinctly unusual and intriguing finding in clinical medicine. A healthy 28-year-old man presented to the emergency department with abdominal pain, nausea and vomiting of 1 day's duration. He did not take any medications, supplements or any unusually coloured food items. The patient was afebrile but had evidence of volume depletion and orthostasis. The abdomen was benign and the physical exam was otherwise unremarkable. Lactated Ringer's solution and 0.9% saline were administered to the patient. He also was given a 10 mg intravenous metoclopramide injection for nausea. The first specimen of urine collected 2 h after the injection was noted to be green. He had last voided 10 h prior to presentation to the hospital. The patient had not noticed any changes in the colour of his urine or stool prior to presentation. Upon admission, the blood urea nitrogen was 4.3 mmol/l and creatinine was 99 µmol/l. A urinalysis revealed specific gravity of 1.025, pH 6.5, trace protein, 2+ glucose, 1+ ketones, trace occult blood and no bilirubin. Blood and urine cultures remained sterile and stool was of normal colour. Ceftazidime and levofloxacin were administered. Computed tomography of abdomen, esophagogastroduodenoscopy and colonoscopy were unremarkable. The colour of urine changed to green-yellow on the third day. By the fourth hospitalization day and until his discharge, the urine remained a clear, yellow colour (Figure 1). His serum creatinine improved to 69 µmol/l. On the ninth hospitalization day, the patient was discharged with a diagnosis of viral gastroenteritis.
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While it is difficult to show a causal link, the temporal association and lack of any other known causes suggest that metoclopramide was the offending agent. The prolonged duration of discoloration may be attributed to renal failure, whereby the clearance of metoclopramide may be as little as 20% of normal [8]. The occurrence of green urine imparts a significant degree of anxiety to the patient, while arousing the clinician's curiosity. It is hoped that with better awareness of healthcare providers regarding benign causes of green urine, lengthy, invasive investigation may be avoided.
Centinela Hospital and Medical Center Inglewood CA, USA Email: firoozpak{at}hotmail.com
Acknowledgments
I am indebted to Ms Lucinda Allshouse for her assistance with retrieval of the reference articles.
Conflict of interest statement. None declared.
References