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Factors influencing nortriptyline steady‐state kinetics: Plasma and saliva levels
Author(s) -
KraghSørensen Per,
Larsen NielsErik
Publication year - 1980
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 - 10.1038/clpt.1980.237
Subject(s) - nortriptyline , saliva , plasma levels , plasma concentration , medicine , clinical pharmacology , endocrinology , chemistry , pharmacology , amitriptyline
Proportionality between dose and steady‐state nortriptyline (NT) plasma levels was found both during initial treatment and after long‐term treatment (years) within the NT Plasma level range of 20 to 296 ng/ml. There were day‐to‐day variations of 10% to 20% (coefficient of variation) but no systematic changes in plasma levels over time. A significant age variation in NT plasma levels was found in 116 patients. Patients over 70 yr of age (n = 23) had higher levels than other age groups (p < 0.001 dose corrected; p < 0.0001 dose and weight corrected). It was found that during episodes of acute inflammatory diseases NT steady‐state plasma levels rose after a change in sedimentation rate. Our data show that the use of saliva rather than plasma in therapeutic drug level monitoring of NT cannot be recommended because the saliva I plasma ratio varied both intra‐ and interindividually by factors of from 2 to 4. Clinical Pharmacology and Therapeutics (1980) 28 , 796–803; doi: 10.1038/clpt.1980.237