Recurrent episodes of life-threatening vasodilatory shock following unintentional intoxication with amlodipine

Calcium channel blockers (CCBs) have a narrow therapeutic index, and their intake in excess is associated with a critical clinical presentation of sustained hypotension and non-cardiogenic pulmonary edema, which are difficult to treat. Unfortunately, the available treatments fail to resuscitate a significant number of patients poisoned by CCBs, rendering them the main cardiovascular drugs involved in death due to overdose. Importantly, in all cases reported until now in the literature, CCB intoxication was known at the time of patients' presentation and the medical challenge solely consisted of the therapeutic approach. In this case report, we describe our experience in treating a 72-year-old patient with recurrent episodes of sustained hypotension refractory to crystalloid and vasoconstrictor infusions. Prolonged pharmacologic support and intermittent sessions of hemofiltration induced stabilization and recovery. The results of an extensive diagnostic workup to elucidate the cause were unfruitful. The recurrent and paroxysmal nature of the clinical presentation along with its incidence after the patient left the protected setting of the hospital led the diagnostic approach to search for a possible external factor, which was shown to be, after toxicological investigation, unintentional amlodipine intoxication.