Voriconazole-induced Severe Hyperkalemia Precipitated by Multiple Drug Interactions

Area of Science:

• Pharmacology
• Clinical Medicine
• Toxicology

Background:

• Voriconazole is a triazole antifungal crucial for treating serious fungal infections.
• Its metabolism occurs via the cytochrome P450 system, and elevated levels can be influenced by drug-drug interactions.
• Azole antifungals may affect adrenal steroid biosynthesis, potentially leading to aldosterone deficiency.

Observation:

• A case study details a patient experiencing recurrent severe hyperkalemia during voriconazole treatment for pulmonary aspergillosis.
• Hyperkalemia episodes were associated with renin-angiotensin-aldosterone system inhibitors and potentially dronedarone, which may increase voriconazole levels.
• Concurrent severe hypercalcemia was noted in one episode, resolving with hemodialysis and dronedarone discontinuation.

Findings:

• Voriconazole was identified as the likely cause of recurrent severe hyperkalemia.
• Switching to itraconazole resolved the hyperkalemia, suggesting voriconazole's direct role.
• The study suggests potential genetic susceptibility, such as CYP2C19 polymorphism, in patients experiencing adverse reactions.

Implications:

• Drug level monitoring is essential for patients on voriconazole, especially those with comorbidities or on interacting medications.
• Clinicians should consider voriconazole-induced hyperkalemia and hypoaldosteronism in patients presenting with these conditions.
• Further investigation into genetic factors like CYP2C19 polymorphism may help predict and manage voriconazole-related adverse events.