Clinical Pharmacokinetics

, Volume 9, Issue 3, pp 261–266 | Cite as

Amitriptyline Dosage Prediction in Elderly Patients from Plasma Concentration at 24 Hours after a Single 100mg Dose

  • S. Dawling
  • S. Ford
  • D. C. Rangedara
  • R. R. Lewis
Original Research Article

Summary

Fifteen depressed elderly patients (14 female, 1 male; mean age 85 years) received a single oral dose of amitriptyline. The concentration of amitriptyline plus nortriptyline in a blood sample taken 24 hours later was used to predict by means of a nomogram the amitriptyline dosage required for each patient. Each dose was selected to produce steady-state amitriptyline plus nortriptyline concentrations close to 140 μg/L. The daily dosage ranged from 20 to 100mg (mean 62mg).

Patients received the individually calculated dose each night, and weekly blood samples were obtained for drug analysis. At 2 weeks, mean amitriptyline plus nortriptyline concentrations were 118 ± 21 μg/L. Eight of the patients were studied for a further 2 weeks and the mean amitriptyline plus nortriptyline concentration was then 111 ± 19 Mg/L.

The dose prediction test is easy to use and ensures each patient receives an adequate but safer dose of amitriptyline than might otherwise be prescribed routinely.

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Copyright information

© ADIS Press Limited 1984

Authors and Affiliations

  • S. Dawling
    • 1
  • S. Ford
    • 1
  • D. C. Rangedara
    • 1
  • R. R. Lewis
    • 1
  1. 1.Poisons Unit, Guy’s Hospital and Guy’s Department of Geriatric and General MedicineNew Cross HospitalLondonEngland

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