Hemodynamic changes following accidental infiltration of a high dose of vasopressin

Severe Bradycardia Associated with the Use of Terlipressin: A Case Report

Introduction

Although terlipressin is known to cause bradycardia, this adverse effect is usually described in association with hypertension and is considered a benign compensatory response mediated by arterial baroreceptors. Cardiac monitoring for patients receiving terlipressin is not routinely recommended.

Case Presentation

A 77-year-old female patient with no history of coronary artery disease and no other coexisting risk factors for cardiac arrhythmias or conduction disturbances was admitted to intensive care unit with severe cholangitis, complicated by variceal bleeding. She developed severe sinus bradycardia following the use of terlipressin, which was associated with significant hypotension that required the infusion of norepinephrine. The bradycardia occurred again when terlipressin therapy was reattempted.

Conclusion

Vasopressin is known to sensitize baroreceptor reflexes by a central mechanism though its actions on V1a receptors in the area postrema, and we speculate that vasopressin analogues such as terlipressin may act in the same manner. That this effect is not widely described in terlipressin safety literature may be due to the overall younger age range of the trial population. This raises the possibility that cardiac monitoring may be warranted for elderly patients receiving terlipressin.

Vasopressin and Its Analogues: From Natural Hormones to Multitasking Peptides

Human neurohormone vasopressin (AVP) is synthesized in overlapping regions in the hypothalamus. It is mainly known for its vasoconstricting abilities, and it is responsible for the regulation of plasma osmolality by maintaining fluid homeostasis. Over years, many attempts have been made to modify this hormone and find AVP analogues with different pharmacological profiles that could overcome its limitations. Non-peptide AVP analogues with low molecular weight presented good affinity to AVP receptors. Natural peptide counterparts, found in animals, are successfully applied as therapeutics; for instance, lypressin used in treatment of diabetes insipidus. Synthetic peptide analogues compensate for the shortcomings of AVP. Desmopressin is more resistant to proteolysis and presents mainly antidiuretic effects, while terlipressin is a long-acting AVP analogue and a drug recommended in the treatment of varicose bleeding in patients with liver cirrhosis. Recently published results on diverse applications of AVP analogues in medicinal practice, including potential lypressin, terlipressin and ornipressin in the treatment of SARS-CoV-2, are discussed.