Pharmacologie cardiovasculaire : libre accès

Abstrait

Calcium Channel Blocker Toxicity in a Cirrhotic Patient

Panagis Galiatsatos, Dachelle Johnson, Ryan E Childers, Deeptankar Demazumder and Sammy Zakaria

Objective

To report a case of profound bradycardia as a result of verapamil toxicity due to impaired metabolism in a cirrhotic patient.

Case report

A 57 year old man with cirrhosis presented with weakness and syncope and a heart rate of twenty beats per minute (bpm). Despite treatment with transcutaneous cardiac pacing, he developed a systole and required eight minutes of cardiopulmonary resuscitation before circulation was restored. After reviewing his medication list, verapamil toxicity was suspected as the etiology for his cardiovascular collapse because of the drug’s poor metabolic clearance in hepatic dysfunction. He was treated for calcium channel blocker toxicity, with calcium, insulin and dextrose infusions. By the seventh day, his blood pressure and heart rate were stable without invasive interventions. However, his liver was unable to recover from the initial shock, leading to the patient’s death.

Discussion

Calcium Channel Blocker (CCB) toxicity is associated with significant morbidity and mortality and is often diagnosed at the time of presentation (e.g. history of overdose). Treatment options include calcium infusion, which can lead to improvements in conduction, inotropy, and blood pressure; and high-dose insulin, which improves myocardial metabolism. These therapies were implemented in the patient, leading to hemodynamic stability, even in the setting of cirrhosis.

Conclusion

Caution is warranted when prescribing calcium channel blockers, such as verapamil, to patients with cirrhosis, since hepatic clearance will most likely be impaired, and may be associated with adverse events. If cirrhotic patients develop CCB toxicity, management is difficult, with few reports of specific treatment strategies.