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Dose‐ranging trial of N‐acetylprocainamide in patients with premature ventricular contractions
Author(s) -
Atkinson Arthur J.,
Lee Woong-Ku,
Quinn Michael L.,
Kushner William,
Nevin Mary Jane,
Strong John M.
Publication year - 1977
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/cpt1977215575
Subject(s) - napa , procainamide , placebo , medicine , adverse effect , dose ranging study , anesthesia , crossover study , cardiology , chemistry , double blind , biochemistry , alternative medicine , pathology
Ten patients with chronic premature ventricular contractions (PVCs) received short‐term oral therapy with N‐acetylprocainamide (NAPA) to determine its antiarrhythmic efficacy and side effects under the conditions of a placebo‐controlled, dose‐ranging trial. NAPA was effective in suppressing PVCs in 8 patients but caused a paradoxical increase in PVC frequency in one. Results were equivocal in the remaining patient because PVCs did not recur when NAPA therapy was withdrawn. Mean NAPA plasma levels as high as 41.1 µg/ml did not have untoward hypotensive or myocardial depressant effects, as judged by electrocardiographic and systolic time intervals. There was, infact, a consistent reduction in PEP/LVET ratio, indicating that NAPA increases the force of myocardial contraction. The mean NAPA elimination half‐life of 10.9 hr was longer than the 6.2 hr half‐life reported for normal subjects, but its prolongation was predictably correlated with reductions in creatinine clearance. Gastrointestinal side effects experienced by 3 patients and insomnia noted by 2 patients are similar to known adverse reactions to procainamide.