Premium
The renal elimination of procainamide
Author(s) -
Galeazzi Renato L.,
Sheiner Lewis B.,
Lockwood Thomas,
Benet Leslie Z.
Publication year - 1976
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1002/cpt197619155
Subject(s) - chemistry , urine , napa , procainamide , alkali metal , excretion , urinary system , endocrinology , medicine , chromatography , biochemistry , organic chemistry
The question of pR or flow dependence for the renal elimination of procainamide (PCA) was studied under 4 conditions in each of 4 subjects. Each subject received 500 mg of PCA intravenously at weekly intervals while in astate of (1) acid load (NR 4 Cl) and water deprivation, (2) acid load and water excess, (3) alkali load (NaRCO 3 ) and water deprivation, and (4) alkali load and water excess. Plasma and urine were collected at frequent intervals for PCA and N‐acetyl PCA (NAPA) analysis. Urine flow rates varied markedly between the water deprivation and water excess states (approximately 1.2 vs 5 ml/min, respectively), and urine pH varied markedly between the acid and alkali load states (pH = ca 5 vs 8, respectively). Despite this marked variation, there were no signijicant changes in PCA renal clearance or 24‐hr PCA or NAPA excretion. If passive diffusion of PCA were taking place, such flow and pR changes would have caused marked changes in PCA clearance were the pH partition hypothesis true. We therefore conclude that passive diffusion is not an important mechanism in the renal elimination of PCA in man and that there must be tubular secretion. The implication for the clinical use of the drug is that dose adjustments need not be made in response to variations in urine flow and pH.