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 The patient was withdrawn from PCPS and IABP 24 hours after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.