Do any of the following medications—sertraline, lacosamide, metoclopramide hydrochloride, ondansetron hydrochloride, ascorbic acid (vitamin C), cholecalciferol (vitamin D3), clonazepam, hydrocodone‑acetaminophen, magnesium oxide, mirabegron, lamotrigine, midazolam (nasal spray), losartan, estradiol, pantoprazole, chlorzoxazone, fluconazole, bethanechol chloride, gabapentin, tramadol—cause urine discoloration?

Urine Discoloration from Medications

None of the medications in this list are known to cause clinically significant urine discoloration, with the exception of ascorbic acid (vitamin C) which may cause false-positive or false-negative results on urine dipstick tests but does not cause visible color change to the naked eye.

Medications That Do NOT Cause Visible Urine Discoloration

The following medications from your list have no documented effects on urine color:

• Sertraline – No urine discoloration reported 1
• Lacosamide – No urine discoloration documented
• Metoclopramide – No urine discoloration reported
• Ondansetron – No urine discoloration documented
• Clonazepam – No urine discoloration reported
• Hydrocodone-acetaminophen – No urine discoloration documented
• Magnesium oxide – No urine discoloration reported
• Mirabegron – No urine discoloration documented
• Lamotrigine – No urine discoloration reported
• Midazolam – No urine discoloration documented
• Losartan – No urine discoloration reported
• Estradiol – No urine discoloration documented
• Pantoprazole – No urine discoloration reported
• Chlorzoxazone – No urine discoloration reported
• Fluconazole – No urine discoloration documented
• Bethanechol – No urine discoloration reported
• Gabapentin – No urine discoloration documented 1
• Tramadol – No urine discoloration reported 2
• Cholecalciferol (vitamin D3) – No urine discoloration documented

Ascorbic Acid (Vitamin C) Considerations

While ascorbic acid does not cause visible urine discoloration, it has important effects on urine testing:

• Ascorbic acid at concentrations above 200 mg% can interfere with urine dipstick tests, causing false-negative results for glucose and hemoglobin 3, 4
• At the 500 mg daily dose prescribed, urinary vitamin C concentrations can reach levels sufficient to interfere with clinical testing 5
• The mean urinary vitamin C concentration in populations taking supplements is approximately 2120 μmol/L, which is well above the threshold for test interference 5
• This interference does not produce visible color change but affects chemical reactions on test strips 4

Common Medications That DO Cause Urine Discoloration (Not in Your List)

For reference, medications that actually cause visible urine discoloration include:

• Rifampin and rifamycins cause universal orange discoloration of urine, sweat, tears, and sputum 1, 6
• Methylene blue causes green urine discoloration, which is benign and self-limited 7

Clinical Pitfalls to Avoid

• Do not assume ascorbic acid causes visible urine color change – it only interferes with dipstick testing 3, 4
• If urine discoloration is observed in this patient, investigate other causes such as hematuria, myoglobinuria, dehydration, or dietary factors rather than attributing it to medications 6
• When performing urinalysis on patients taking vitamin C supplements, use dipstick tests resistant to ascorbic acid interference or check for urinary vitamin C levels first 4, 5