Mixed amlodipine/valsartan overdose treated by the molecular adsorbent recirculating system (MARS™)

We describe the case of a 58-year-old woman who developed a severe distributive shock following the intentional ingestion of a large overdose of amlodipine (480 mg) combined with valsartan (3680 mg). Extreme vasoplegia remained refractory to maximal standard therapy including fluid resuscitation, intravenous calcium, vasopressors at very high doses, hyperinsulinemia-euglycemia therapy, lipid emulsion, and methylene blue administration. Besides, the patient exhibited hyperglycemia refractory to very high doses of insulin. Due to its theoretical ability to effectively remove protein-bound drugs such as amlodipine from the circulation, albumin dialysis with the molecular adsorbent recirculating system (MARS™) was performed during two consecutive sessions. Blood was drawn for toxicokinetic calculations. Amlodipine elimination half-life during the first MARS™ session was calculated at 7.6 h. In addition, there was a rapid fall in blood glucose, requiring the introduction of a continuous infusion of glucose in order to achieve euglycemia. Moreover, a few hours after the initiation of the MARS™ therapy, the hemodynamic status was not significantly modified but a significant tapering of epinephrine infusion was possible, together with a progressive decrease of blood lactate level. However, the need for vasopressors in decreasing doses was present until day 5 post-ingestion. Eventually, the patient fully recovered and was discharged home 8 days after admission.

The role of the MARS™ in the treatment of severe poisoning of calcium channel blockers is still to be defined. We were able to demonstrate a relatively short elimination half-life of amlodipine. A decreased insulin resistance and a reduction of epinephrine infusion were also observed.