Toward quantification of loop diuretic responsiveness for congestive heart failure

Abstract

Diuretics, such as furosemide, are routinely administered to dogs with congestive heart failure (CHF). Traditionally, dose and determination of efficacy primarily are based on clinical signs rather than quantitative measures of drug action. Treatment of human CHF patients increasingly is guided by quantification of urine sodium concentration (uNa) and urine volume after diuretic administration. Use of these and other measures of diuretic responsiveness is associated with decreased duration of hospitalization, complication rates, future rehospitalization, and mortality. At their core, loop diuretics act through natriuresis, and attention to body sodium (Na) stores and handling offers insight into the pathophysiology of CHF and pharmacology of diuretics beyond what is achievable from clinical signs alone. Human patients with low diuretic responsiveness or diuretic resistance are at risk for difficult or incomplete decongestion that requires diuretic intensification or other remedial strategies. Identification of the specific etiology of resistance in a patient can help tailor personalized interventions.In this review, we advance the concept of loop diuretic responsiveness by highlighting Na and natriuresis. Specifically, we review body water homeostasis and congestion in light of the increasingly recognized role of interstitial Na, propose definitions for diuretic responsiveness and resistance in veterinary subjects, review relevant findings of recent studies, explain how the particular cause of resistance can guide treatment, and identify current knowledge gaps. We believe that a quantitative approach to loop diuretic usage primarily involving natriuresis will advance our understanding and care of dogs with CHF.

Dermatologic adverse effect of subcutaneous furosemide administration in a cat

“…In stable small animals, the chronic (home-based) management of CHF is usually based on oral furosemide, as this route of administration is relatively simple for the majority of owners and well tolerated by dogs and cats ( Kittleson and Kienle, 1998 ; Plumb, 2008 ; Sabetti et al , 2022 ). However, as the bioavailability of oral furosemide is variably limited, in some cases, oral administration prevents good control of CHF, especially in advanced cardiac diseases or subjects affected by concomitant gastrointestinal disorders ( Kittleson and Kienle, 1998 ; Plumb, 2008 ; Oyama and Adin, 2022 ). One way to favor the patient’s decongestion at home is to change the administration route from the oral to the parenteral one.…”

“…One way to favor the patient’s decongestion at home is to change the administration route from the oral to the parenteral one. This change aims to use a formulation of furosemide with a higher bioavailability and to deliver the medication via a route that may bypass the gastrointestinal tract, overcoming problems related to impaired absorption ( Kittleson and Kienle, 1998 ; Plumb, 2008 ; Oyama and Adin, 2022 ). The intramuscular injection of furosemide is a cited option in veterinary literature ( Kittleson and Kienle, 1998 ; Plumb, 2008 ); however, this route of administration requires specific technical skills of the owners ( Baxter and Evans, 1973 ) and may not be tolerated by some cats.…”