Steady-state plasma levels of nortriptyline in twins: Influence of genetic factors and drug therapy
- 27 December 1969
- Vol. 4 (5686), 764-768
- https://doi.org/10.1136/bmj.4.5686.764
Abstract
Nineteen identical (monozygotic) and 20 fraternal (dizygotic) sets of twins between 45 and 51 years of age were given nortriptyline orally in doses of 0·2 mg./kg. body weight three times daily for eight days. The steady-state plasma concentrations of nortriptyline were calculated from the mean of the determinations for days 6, 7, and 8. Identical twins, not treated with other drugs, achieved similar steady-state plasma concentrations of nortriptyline in contrast to fraternal twins who were not given other drugs. The intrapair similarity in steady-state plasma concentrations was not found in identical twins simultaneously treated with various drugs during the experiment. Identical and fraternal twins treated with drugs containing barbiturates had considerably lower steady-state plasma concentrations of nortriptyline compared with untreated twins. It is concluded that most of the variability in nor-triptyline steady-state plasma concentration between persons who have not received drugs is genetically determined. Exposure to other drugs also influences the steady-state plasma concentration of nortriptyline, which in a given patient may therefore be determined by a resultant of genetic and environmental factors.Keywords
This publication has 14 references indexed in Scilit:
- Genetic Control of Drug Levels in Man: AntipyrineScience, 1968
- PHENYLBUTAZONE AND ISONIAZID METABOLISM IN PATIENTS WITH LIVER DISEASE IN RELATION TO PREVIOUS DRUG THERAPYThe Lancet, 1968
- Rate of accumulation and plateau plasma concentration of drugs after chronic medicationJournal of Pharmacy and Pharmacology, 1968
- Plasma levels of monomethylated tricyclic antidepressants during treatment with imipramine-like compoundsLife Sciences, 1967
- SOME PHARMACOLOGICAL CONSEQUENCES OF SPECIES VARIATION IN RATES OF METABOLISM1967
- Enzyme Stimulation and Inhibition in the Metabolism of Drugs1965
- The metabolism of nortriptyline-N-methyl-14C in ratsBiochemical Pharmacology, 1963
- Aspects of the Clinical Chemistry of Desmethylimipramine in ManJournal of Pharmacy and Pharmacology, 1963
- QUANTITATIVE METHODEN ZUR UNTERSUCHUNG DES STOFFWECHSELS VON TOFRANIL1963
- [Activity of expired carbon dioxide, CNS and other organs after the administration of C14-labelled N-(gamma-dimethyl-aminopropyl)-iminodibenzyl (psychopharmacological drug Tofranil) to rats and dogs].1962