Abstract Introduction Atovaquone is an antimicrobial drug that is used in clinical practice for prophylaxis against Pneumocystis jirovecii pneumonia (PJP), especially when first-line therapy cannot be used. Although the side effect profile of this drug is well tolerated, rare but serious neuropsychiatric and electrolyte derangements can happen. Case Description A woman in her seventies with a history of interstitial lung disease (ILD), group II pulmonary hypertension, and heart failure with preserved ejection fraction developed acute neuropsychiatric changes, evidenced by delirium and visual hallucinations within 24 hours of receiving atovaquone for PJP prophylaxis along with prednisone and mycophenolate mofetil. Her sodium levels were very low (110s). This led to high suspicion of medication-related adverse effects, resulting in discontinuation of all immunosuppressive medications. She was treated with supportive measures, including electrolyte correction, until her sodium levels normalized and her mental status rapidly improved. After recovery, she restarted prednisone and mycophenolate mofetil sequentially, both of which were well tolerated without recurrence of symptoms, confirming atovaquone as the likely cause. Discussion This case highlights the importance of considering acute hyponatremia as a cause of delirium or acute neuropsychiatric changes, especially in patients who are on certain medications, including atovaquone. This abstract is funded by: None
Salem et al. (Fri,) studied this question.