Lactic Acidosis Induced by Excessive Use of a Long-Acting Beta Agonist

Lactic acidosis is associated with poorer clinical outcomes in critical care. The causes of this condition are divided into two groups: type A (tissue hypoxia) and type B (metabolic abnormalities). Of these, drug-induced lactic acidosis is categorized as type B and is often overlooked due to clinicians' poor awareness. We herein report a rare case of drug-induced lactic acidosis due to excessive use of a long-acting beta agonist (LABA) in a patient with asthma-chronic obstructive pulmonary disease overlap exacerbation. He initially presented with markedly elevated lactate and metabolic acidosis with unknown etiology. A detailed medical interview revealed that he had inhaled a large amount of LABA on the day of admission, which led to our final diagnosis. The patient's respiratory status and lactate levels gradually improved with the appropriate use of inhalation therapy. While there have been many recent reports of lactic acidosis caused by short-acting beta agonists, our case suggests that excessive use of LABAs may also lead to lactic acidosis. Clinicians should be aware of the possibility that LABAs can cause lactic acidosis because poor awareness of the condition may lead to inappropriate patient care.