The electrocardiogram showed bradycardia with a wide QRS of 146 msec and HR 40/min (Figure 1). The initial serum concentration of pilsicainide hydrochloride was abnormally high at 12.46 μg/mL (therapeutic range: 0.2–0.9 μg/mL).
The patient’s clinical course is shown in Figure 2. As he was in cardiac arrest on hospital arrival, a peripheral venous catheter was inserted and tracheal intubation was performed. A total of 10 A of adrenaline was administered for resuscitation, but return of spontaneous circulation did not occur, so percutaneous cardiopulmonary support (PCPS) (Getinge CS300 with TERUMO CAPIOX ME-SP200C) was established 40 minutes after arrival to maintain circulation. A contrast-enhanced computed tomography scan showed no findings affecting respiration and circulation. The patient was admitted to the intensive care unit (ICU), and hemodialysis (HD) with a NIKKISO DBB-100NX was introduced for drug removal, and intra-aortic balloon pumping (IABP) with a Getinge CS300 was used to support circulation. Echocardiography in the ICU showed a visual ejection fraction (EF) of about 10–15%. After induction of HD, ventricular tachycardia (VT) was observed (Figure 1). Cardioversion at 200 J with a Stryker LIFEPAK 20e was performed to restore normal sinus rhythm, and magnesium sulfate (20 mEq/L) was administered for arrhythmia prevention. His visual EF on echocardiography began to show gradual improvement. There was no recurrence of arrhythmia, and after 8 total hours of HD, the serum concentration of pilsicainide had decreased to 2.98 μg/mL. The patient was withdrawn from PCPS and IABP 24 hours after arrival at our hospital, and after 28 hours, the patient was weaned from mechanical ventilation. On the third hospital day, the patient’s serum concentration of pilsicainide had decreased to 1.51 μg/mL, and he was transferred to another hospital for treatment of his psychological problems. On the transfer to another hospital, his vital signs remained stable, and he experienced no disturbance of consciousness. Five months later, we followed up the patient and his neurological prognosis is favorable and had no recurrent arrhythmias.
3. Discussion
Pilsicainide hydrochloride was one of the most frequently used antiarrhythmic drugs in Japan. The effective serum concentration of pilsicainide hydrochloride is 0.2–0.9 μg/ml, with marked PQ prolongation reported at levels of 0.98 μg/ml or higher and adverse effects likely to occur at levels exceeding 0.9 μg/ml3). The highest serum concentration in our patient was 12.46 μg/ml, and PCPS was established because of the difficulty in maintaining his circulation on admission.
The reported cases of poisoning by pilsicainide overdose are summarized in Table 2.