Lactic acidosis following intentional overdose by inhalation of salmeterol and fluticasone

Abstract

Salmeterol, a long-acting β2-adrenergic receptor agonist used for the treatment of asthma and chronic obstructive pulmonary disease, has an adverse effects profile that is similar to that of salbutamol and other β2-agonists. We report a sympathomimetic syndrome with metabolic acidosis and hyperlactatemia after intentional inhalation of salmeterol in a suicide attempt. A 16-year-old female patient was admitted to the emergency department approximately 2 hours after having inhaled 60 puffs of a combination of salmeterol xinafoate 25 μg and fluticasone propionate 50 μg. She presented in an anxious state with complaints of palpitations and chest pain. The electrocardiogram demonstrated sinus tachycardia and ST-segment depression in the inferior and anterolateral leads. Laboratory findings showed hypokalemia, hypophosphatemia, and lactic acidosis. Cardiac troponin I and creatine kinase MB remained within the normal range. Treatment was supportive and included intravenous fluids and cautious potassium supplementation. The next day, electrocardiographic and laboratory findings returned to normal. We hypothesize that stimulation of β2-adrenergic receptors by inhalation of salmeterol caused this patient's lactic acidosis. This observation is consistent with the hypothesis that the hyperlactatemia observed during asthma attacks is due in part to the administration of high doses of β2-agonists. Salmeterol overdose by inhalation appears to be sufficient to cause lactic acidosis. © Canadian Association of Emergency Physicians.