Unveiling an Uncommon Complication: Pleural Effusion Secondary to Pioglitazone Use

Pioglitazone, a peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist, is used in the treatment of type 2 diabetes mellitus by reducing insulin resistance. While peripheral edema and fluid retention are well-documented adverse effects, isolated pleural effusion in the absence of heart failure is rare. We present the fourth reported case of a woman in her 60s with type 2 diabetes who developed recurrent left-sided pleural effusion after the initiation and dose escalation of pioglitazone. The effusion resolved completely following discontinuation of the drug. This case underscores the importance of early recognition of drug-induced pleural effusion and timely cessation of the offending agent to prevent morbidity.