Abstract
Acute drug overdose is common among emergency outpatients. We present such a case caused by an overdose of loxoprofen, in which we measured the serum concentrations of loxoprofen and its metabolites. A woman in her 30s took 3,600 mg of loxoprofen and came to the emergency room 3 hours later. There were no subjective symptoms, vital signs were stable and consciousness was clear. She was hospitalized for the observation, with no particular abnormalities found in laboratory tests. The patient refused administration of activated charcoal and an aperient. The following day, digestive symptoms, mild liver dysfunction, acute kidney injury, and thrombocytopenia developed, which worsened by day 3 of hospitalization. Thereafter, symptoms and blood tests improved, and she was discharged on day 4 with no sequelae. The blood concentration of loxoprofen was 126μg/ml at 3 hours, 26μg/ml at 17 hours, 3.18μg/ml at 40 hours, and 0.25μg/ml at 64 hours after ingestion. The maximum concentration of loxoprofen was estimated to occur at 0.41 hours and absorption lag was not observed. The drug was absorbed within 3.5 hours after ingestion. Furthermore, metabolization to an activator occurred quickly, while the half-life of the drug was prolonged, due to egestion delay.
