The Possibility of Therapeutic Drug Monitoring of the Most Important Interactions in Nursing Homes

Author(s): Pernille Schjøtt, Martina Šutovská, Jan Schjøtt*

Journal Name: Current Clinical Pharmacology
Continued as Current Reviews in Clinical and Experimental Pharmacology

Volume 14 , Issue 2 , 2019

Graphical Abstract:


Background: Therapeutic drug monitoring is a relevant tool in drug treatment of elderly patients. The aim of this study was to assess the possibility of therapeutic drug monitoring of the most important potential interactions in nursing homes.

Methods: A material of prescribed drugs to 446 patients in three nursing homes in Bergen, Norway from a single day in March 2016 was analysed. Clinically relevant drug interactions (pharmacodynamic or pharmacokinetic) were identified and classified with Stockley`s Interaction Alerts. The most important interaction among several in each patient were ranked by recommended action > severity > evidence according to Stockley`s. The possibility of therapeutic drug monitoring of drug combinations involved in the most important interactions was retrieved from a database of all laboratories performing clinical pharmacology in Norway (the Pharmacology Portal).

Results: Two or more drugs were used by 443 (99.3%) of 446 patients. Three-hundred and eightyfour patients (86.1%) had > 1 interaction. About 95% of the most important interactions were pharmacodynamic. In 280 (72.9%) of these interactions, Stockley`s recommended adjust dose or monitoring. Among the 384 most important interactions, 93% involved one drug and 41% involved two drugs available for therapeutic drug monitoring.

Conclusion: In this pilot study, therapeutic drug monitoring was possible in the majority of the most important interactions in Norwegian nursing homes. This option is of importance since adjust dose or monitoring were frequently recommended actions associated with these interactions.

Keywords: Databases, drug interactions, elderly patients, nursing homes, pharmacotherapy, therapeutic drug monitoring.

Onder G, Liperoti R, Fialova D, et al. Polypharmacy in nursing home in Europe: results from the SHELTER study. J Gerontol A Biol Sci Med Sci 2012; 67(6): 698-704.
[] [PMID: 22219520]
Gallagher PF, Barry PJ, Ryan C, Hartigan I, O’Mahony D. Inappropriate prescribing in an acutely ill population of elderly patients as determined by Beers’ Criteria. Age Ageing 2008; 37(1): 96-101.
[] [PMID: 17933759]
Mangoni AA, Jackson SH. Age-related changes in pharmacokinetics and pharmacodynamics: basic principles and practical applications. Br J Clin Pharmacol 2004; 57(1): 6-14.
[ 10.1046/j.1365-2125.2003.02007.x] [PMID: 14678335]
Leendertse AJ, Egberts AC, Stoker LJ, van den Bemt PM. Frequency of and risk factors for preventable medication-related hospital admissions in the Netherlands. Arch Intern Med 2008; 168(17): 1890-6.
[PMID: 18809816]
Pirmohamed M, James S, Meakin S, et al. Adverse drug reactions as cause of admission to hospital: prospective analysis of 18 820 patients. BMJ 2004; 329(7456): 15-9.
[] [PMID: 15231615]
Adaway JE, Keevil BG. Therapeutic drug monitoring and LC-MS/MS. J Chromatogr B Analyt Technol Biomed Life Sci 2012; 883-884: 33-49.
[] [PMID: 21992751]
Ghiculescu RA. Therapeutic drug monitoring: which drugs, why, when and how to do it. Aust Prescr 2008; 31: 42-4.
Cooney L, Loke YK, Golder S, et al. Overview of systematic reviews of therapeutic ranges: methodologies and recommendations for practice. BMC Med Res Methodol 2017; 17(1): 84.
[ 10.1186/s12874-017-0363-z] [PMID: 28577540]
Feyz L, Bahmany S, Daemen J, et al. Therapeutic drug moni-toring to assess drug adherence in assumed resistant hyper-tension: a comparison with directly observed therapy in three non-adherent patients. J Cardiovasc Pharmacol 2018; 72(2): 117-20.
[PMID: 29878936]
Hermann M, Waade RB, Molden E. Therapeutic Drug Monitoring of Selective Serotonin Reuptake Inhibitors in Elderly Patients. Ther Drug Monit 2015; 37(4): 546-9.
[ 0000000000000169] [PMID: 25565671]
Hiemke C, Bergemann N, Clement HW, et al. Consensus Guidelines for Therapeutic Drug Monitoring in Neuropsychopharmacology: Update 2017. Pharmacopsychiatry 2018; 51(1-02): 9-62.
[PMID: 28910830]
WHO Collaborating Centre for Drug Statistics Methodology. 2016.
Stockley’s Interaction Alerts.
Karlsen Bjånes T, Mjåset Hjertø E, Lønne L, et al. Pharmacology Portal: An Open Database for Clinical Pharmacologic Laboratory Services. Clin Ther 2016; 38(1): 222-6.
[] [PMID: 26546404]
Waade RB, Molden E, Refsum H, Hermann M. Serum concentrations of antidepressants in the elderly. Ther Drug Monit 2012; 34(1): 25-30.
[] [PMID: 22215489]
Selbaek G, Kirkevold Ø, Engedal K. The course of psychiatric and behavioral symptoms and the use of psychotropic medication in patients with dementia in Norwegian nursing homes--a 12-month follow-up study. Am J Geriatr Psychiatry 2008; 16(7): 528-36.
[] [PMID: 18591573]
Kongsholm GG, Nielsen AK, Damkier P. Drug interaction databases in medical literature: transparency of ownership, funding, classification algorithms, level of documentation, and staff qualifications. A systematic review. Eur J Clin Pharmacol 2015; 71(11): 1397-402.
[] [PMID: 26369536]
Medical Dictionary for Regulatory Activitites (MedDRA). Available at (Accessed Dec 11, 2018).
SNOMED CT. Available at (Accessed Dec 11, 2018).
Fries BE, Wodchis WP, Blaum C, Buttar A, Drabek J, Morris JN. A national study showed that diagnoses varied by age group in nursing home residents under age 65. J Clin Epidemiol 2005; 58(2): 198-205.
[] [PMID: 15680755]

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Article Details

Year: 2019
Published on: 24 December, 2018
Page: [152 - 156]
Pages: 5
DOI: 10.2174/1574884714666181224144722

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