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Falsely elevated urinary excretion of catecholamines and metanephrines in patients receiving labetalol therapy.

Publication ,  Journal Article
Feldman, JM
Published in: J Clin Pharmacol
April 1987

Five patients with essential hypertension who were receiving treatment with the beta- and alpha-adrenoreceptor-blocking drug labetalol had elevated urinary excretion of catecholamines. When measured with a radioenzymatic assay, all five subjects had elevated urinary excretion of norepinephrine and normal urinary excretion of epinephrine; when measured with a fluorometric assay, four subjects had elevated urinary excretion of epinephrine with normal urinary excretion of norepinephrine, and one subject had elevated urinary norepinephrine excretion with normal urinary excretion of epinephrine. In three subjects who could be reevaluated three days to two months after labetalol therapy was discontinued, the urinary catecholamine levels had returned toward normal. Our studies indicate that labetalol produced a false elevation of urinary catecholamine levels. Although labetalol also interfered with the measurement of urinary excretion of metanephrine, it did not interfere with the measurement of urinary excretion of vanillylmandelic acid, homovanillic acid, 5-hydroxyindoleacetic acid, and serotonin, and it probably did not interfere with the measurement of plasma concentrations of dopamine, norepinephrine, and epinephrine. We conclude that labetalol therapy should be discontinued, and another beta-blocking drug, such as propranolol, that does not interfere with these tests should be temporarily substituted at least three days before a patient collects a 24-hour urine for measurement of the urinary excretion of catecholamines and metanephrine.

Duke Scholars

Published In

J Clin Pharmacol

DOI

ISSN

0091-2700

Publication Date

April 1987

Volume

27

Issue

4

Start / End Page

288 / 292

Location

England

Related Subject Headings

  • Radioimmunoassay
  • Pharmacology & Pharmacy
  • Middle Aged
  • Metanephrine
  • Male
  • Labetalol
  • Hypertension
  • Humans
  • Female
  • False Positive Reactions
 

Citation

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Feldman, J. M. (1987). Falsely elevated urinary excretion of catecholamines and metanephrines in patients receiving labetalol therapy. J Clin Pharmacol, 27(4), 288–292. https://doi.org/10.1002/j.1552-4604.1987.tb03015.x
Feldman, J. M. “Falsely elevated urinary excretion of catecholamines and metanephrines in patients receiving labetalol therapy.J Clin Pharmacol 27, no. 4 (April 1987): 288–92. https://doi.org/10.1002/j.1552-4604.1987.tb03015.x.
Feldman, J. M. “Falsely elevated urinary excretion of catecholamines and metanephrines in patients receiving labetalol therapy.J Clin Pharmacol, vol. 27, no. 4, Apr. 1987, pp. 288–92. Pubmed, doi:10.1002/j.1552-4604.1987.tb03015.x.
Journal cover image

Published In

J Clin Pharmacol

DOI

ISSN

0091-2700

Publication Date

April 1987

Volume

27

Issue

4

Start / End Page

288 / 292

Location

England

Related Subject Headings

  • Radioimmunoassay
  • Pharmacology & Pharmacy
  • Middle Aged
  • Metanephrine
  • Male
  • Labetalol
  • Hypertension
  • Humans
  • Female
  • False Positive Reactions