Voriconazole-associated salt-losing nephropathy.

Area of Science:

• Nephrology
• Clinical Pharmacology
• Internal Medicine

Background:

• Focal segmental glomerulosclerosis (FSGS) is a common cause of nephrotic syndrome.
• Antifungal medications like voriconazole (VRCZ) are crucial for treating deep mycosis but can have adverse effects.
• Hyponatremia is a potential complication of VRCZ therapy.

Observation:

• A 74-year-old male with FSGS developed hyponatremia, liver dysfunction, and volume depletion during VRCZ treatment.
• The patient presented with somnolence, malaise, hypotension, and decreased skin turgor.
• Elevated antidiuretic hormone (ADH) and plasma renin activity were noted, with high urinary sodium excretion despite volume depletion.

Findings:

• The patient was diagnosed with voriconazole-associated salt-losing nephropathy (SLN).
• Discontinuation of VRCZ and fluid resuscitation led to improvement in hyponatremia, liver dysfunction, and consciousness.
• The clinical presentation suggested a diagnosis of SLN, distinct from syndrome of inappropriate ADH secretion (SIADH) alone.

Implications:

• Salt-losing nephropathy (SLN) should be considered in patients treated with voriconazole (VRCZ) who develop hyponatremia.
• Distinguishing SLN from SIADH is critical for appropriate management of VRCZ-induced hyponatremia.
• This case highlights the importance of monitoring electrolyte balance and renal function in patients receiving VRCZ.