HRS and clonidine

Q: Which of the Clonidine is helpful in hepatorenal syndrome? (select one)

A) Oral

B) Intravenous

Answer: B

The pathology of hepatorenal syndrome is extremely complex involving many mechanisms mainly consisting of:

• Arterial vasodilatation in the splanchnic circulation triggered by nitric oxide activity.
• Progressive rise in cardiac output and fall in systemic vascular resistance (SVR)
• Hypotension-induced activation of the renin-angiotensin and sympathetic nervous systems
• Bacterial translocation from the intestine into the mesenteric lymph nodes
• Decline in kidney perfusion associated with a decrease in glomerular filtration rate (GFR) and sodium excretion

Intravenous (IV) clonidine, which is a sympatholytic agent increases the renal blood flow and subsequently raises the GFR by about 25 percent. Interestingly this effect is not demonstrated with oral ingestion.

Given the above pathogenesis of hepatorenal syndrome, ornipressin or other vasopressin analogs help by elevating mean arterial pressure, reducing plasma renin activity and norepinephrine concentration, increase in renal blood flow, and GFR and sodium excretion.

#hepatology

#nephrology

References:

1. Esler M, Dudley F, Jennings G, et al. Increased sympathetic nervous activity and the effects of its inhibition with clonidine in alcoholic cirrhosis. Ann Intern Med 1992; 116:446.

2.  Mindikoglu AL, Pappas SC. New Developments in Hepatorenal Syndrome. Clin Gastroenterol Hepatol 2018; 16:162.

3. Runyon BA, Squier S, Borzio M. Translocation of gut bacteria in rats with cirrhosis to mesenteric lymph nodes partially explains the pathogenesis of spontaneous bacterial peritonitis. J Hepatol 1994; 21:792.

4. Lenz K, Hörtnagl H, Druml W, et al. Ornipressin in the treatment of functional renal failure in decompensated liver cirrhosis. Effects on renal hemodynamics and atrial natriuretic factor. Gastroenterology 1991; 101:1060.