Midodrine;

What pharmacological options should I consider when treating neurogenic orthostatic hypotension in my elderly patient with supine hypertension?

FA Manian MD, MPH, , , , , Leave a comment

Treating symptomatic neurogenic orthostatic hypotension (nOH) in patients with supine hypertension can be challenging.

Before adding new agents, consider discontinuation or dose reduction of medications that can potentially aggravate orthostatic symptoms (eg, diuretics, vasodilators, negative chronotropic agents, including beta blockers).

Midodrine (an α1-adrenoreceptor agonist) and droxidopa (a norepinephrine pro-drug) are the only 2 FDA-approved drugs for the treatment of OH.

  • Midodrine is typically dosed between 2.5 mg-15 mg 1-3x/d during waking hours (prior to getting out of bed, before lunch, mid-afternoon).
  • Droxidopa is dosed from 100-600 mg 3x/day during waking hours (eg, 8 AM, noon, 4PM).
  • To reduce the risk of supine hypertension, these agents are not recommended to be taken within 5 h of bedtime, and should be used with caution in patients with congestive heart failure and chronic renal failure.

Fludrocortisone and pyridostigmine are used off-label for treatment of nOH.

  • Fludrocortisone (typical dose 0.1-0.2 mg/day) expands intravascular blood volume by increasing renal sodium and water reabsorption, with an attendant risk of exacerbating supine hypertension, hypokalemia, and edema.
  • Pyridostigmine (typical dose 30-60 mg 1-3x/day) is an acetylcholinesterase inhibitor that potentiates neurotransmission in the sympathetic ganglia and has the advantage of not worsening supine hypertension. Side effects include abdominal cramps, diarrhea, excessive sweating and urinary incontinence.

In practice,  1 or more of these agents are often used along with non-pharmacological measures.

Also go to a related P4P pearl here. 

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Reference

Gibbons CH, Schmidt P, Biaggioni I, et al. The recommendations of a concensus panel for the screening, diagnosis, and treatment of neurogenic orthostatic hypotension and associated supine hypertension. J Neurol 2017;264:1567-82.https://www.ncbi.nlm.nih.gov/pubmed/28050656

 

What pharmacological options should I consider when treating neurogenic orthostatic hypotension in my elderly patient with supine hypertension?

The serum creatinine of my patient originally admitted for management of tense ascites is slowly rising. How concerned should I be?

FA Manian MD, MPH, , , , , , , , Leave a comment

Although the causes of increasing serum creatinine (SCr) in patients with cirrhosis are legion (eg, sepsis, acute tubular injury, and intravascular volume depletion due to over-diuresis, gastrointestinal bleed, or other causes), the most feared cause is often hepatorenal syndrome (HRS). HRS is a functional renal impairment that reflects the final pathophysiological stages of systemic circulatory impairment1, and significantly contributes to a worsening prognosis in patients with cirrhosis2. For example, without treatment, in patients whose SCr doubles in less than 2 weeks (type I HRS) the median survival is less than 2 weeks , while in those who develop a more gradual renal impairment (type II HRS) the median survival is 6 months3.

Physiologically, HRS is a culmination of significant vasodilation in the splanchnic arteries which, in time, leads to reduced organ perfusion due to a drop in the cardiac output. The associated increase in the activity of the renin-angiotensin-aldosterone and the sympathetic nervous systems contributes to sodium and water retention, and further exacerbates intra-renal vasoconstriction and ascites3.

The primary goal in the medical management of HRS is to increase splanchnic vascular resistance4, often by administering a combination of IV albumin, octreotide and other vasoconstricting agents (eg, midodrine, norepinephrine, or terlipressin [unavailable in US and Canada]).  Of interest, in addition to expanding the circulating plasma volume, albumin may have a vasoconstricting effect by binding to endotoxins, nitric oxide, bilirubin and fatty acids4!

 

References

  1. Arroyo V, Fernandez J, Gines P. Pathogenesis and treatment of hepatorenal syndrome. Semin Liver Dis 2008;28:81-95.
  2. Salerno F, Gerbes A, Ginès P, et al. Diagnosis, prevention and treatment of hepatorenal syndrome in cirrhosis. Gut. 2007 Sep;56(9):1310-8.
  3. Cardenas A, Gines P. A Patient with cirrhosis and increasing creatinine Level: What Is It and what to do? Clin Gatroenterol Hepatol 2009;7:1287–1291. 
  4. Baraldi O, Valentini C, Donati G, et al. Hepatorenal syndrome: Update on diagnosis and treatment. World J Nephrol. 2015;4:511-20.

Contributed by Alireza Sameie, Medical Student, Harvard Medical School

The serum creatinine of my patient originally admitted for management of tense ascites is slowly rising. How concerned should I be?