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Potential drug interactions during a three-decade study period: a cross-sectional study of a prescription register

  • Pharmacoepidemiology and Prescription
  • Published:
European Journal of Clinical Pharmacology Aims and scope Submit manuscript

An Erratum to this article was published on 25 September 2007

Abstract

Objectives

The increased risk of adverse events in patients receiving potentially interacting drugs has long been recognized. The purpose of the present study was to evaluate the change in the risk of receiving potentially interacting drugs during a period covering three decades and to examine the relative risk of actual drug combinations.

Methods

The prescriptions from all individuals (about 8,000) with two or more prescriptions during three periods of 15 months, October to December 1983–1984, 1993–1994 and 2003–2004, were collected from an ongoing cohort study in the county of Jämtland, Sweden. The potential interactions were detected by a computerized system.

Results

The relative risk (RR) of receiving potentially interacting drugs increased for type C interactions [RR: 1.177, 95% confidence interval (CI): 1.104–1.256] and decreased for type D interactions (RR: 0.714, 95% CI: 0.587–0.868) from the period 1983–1984 to 2003–2004. Polypharmacy for the participants increased by 61%, from 9.05 filled prescriptions per subject in 1983–1984 to 10.6 in 1993–1994 and 14.6 in 2003–2004. The RR was positively correlated to the pronounced increase in polypharmacy; in addition, an exponential relationship was found for the more severe type D interactions. Few interacting drug combinations were responsible for a large proportion of the risk.

Conclusion

We conclude that the risk of receiving potentially interacting drugs was strongly correlated to the concomitant use of multiple drugs. The pronounced increase in polypharmacy over time implies a growing reason for prescribers and pharmacists to be aware of drug interactions. Recently established national prescription registers should be evaluated for drug interaction vigilance, both clinically and epidemiologically.

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References

  1. Aronson JK (2004) In defence of polypharmacy. Br J Clin Pharmacol 57(2):119–120

    Article  PubMed  CAS  Google Scholar 

  2. Aronson JK (2004) Rational prescribing, appropriate prescribing. Br J Clin Pharmacol 57(3):229–230

    Article  PubMed  CAS  Google Scholar 

  3. Astrand B, Astrand E, Antonov K, Petersson G (2006) Detection of potential drug interactions - a model for a national pharmacy register. Eur J Clin Pharmacol 62(9):749–756

    Article  PubMed  Google Scholar 

  4. Astrand B, Hovstadius B, Antonov K, Petersson G (2007) The Swedish national pharmacy register. In: MEDINFO 2007 Proceedings. (in press)

  5. Bjorkman IK, Fastbom J, Schmidt IK, Bernsten CB (2002) Drug-drug interactions in the elderly. Ann Pharmacother 36(11):1675–1681

    Article  PubMed  CAS  Google Scholar 

  6. Boethius G, Wiman F (1977) Recording of drug prescriptions in the county of Jamtland, Sweden. I. Methodological aspects. Eur J Clin Pharmacol 12(1):31–35

    Article  PubMed  CAS  Google Scholar 

  7. Hansagi H, Olsson M, Sjoberg S, Tomson Y, Goransson S (2001) Frequent use of the hospital emergency department is indicative of high use of other health care services. Ann Emerg Med 37(6):561–567

    Article  PubMed  CAS  Google Scholar 

  8. Huang SM, Lesko LJ (2004) Drug-drug, drug-dietary supplement, and drug-citrus fruit and other food interactions: what have we learned? J Clin Pharmacol 44(6):559–569

    Article  PubMed  CAS  Google Scholar 

  9. Kaufman DW, Kelly JP, Rosenberg L, Anderson TE, Mitchell AA (2002) Recent patterns of medication use in the ambulatory adult population of the United States: the Slone survey. JAMA 287(3):337–344

    Article  PubMed  Google Scholar 

  10. Lafata JE, Schultz L, Simpkins J, Chan KA, Horn JR, Kaatz S et al (2006) Potential drug-drug interactions in the outpatient setting. Med Care 44(6):534–541

    Article  PubMed  Google Scholar 

  11. Leape LL, Bates DW, Cullen DJ, Cooper J, Demonaco HJ, Gallivan T et al (1995) Systems analysis of adverse drug events. ADE Prevention Study Group. JAMA 274(1):35–43

    Article  PubMed  CAS  Google Scholar 

  12. Linnarsson R (1993) Drug interactions in primary health care. A retrospective database study and its implications for the design of a computerized decision support system. Scand J Prim Health Care 11(3):181–186

    PubMed  CAS  Google Scholar 

  13. Merlo J, Liedholm H, Lindblad U, Bjorck-Linne A, Falt J, Lindberg G et al (2001) Prescriptions with potential drug interactions dispensed at Swedish pharmacies in January 1999: cross sectional study. Br Med J 323(7310):427–428

    Article  CAS  Google Scholar 

  14. PubMed National Library of Medicine. Available from: http://www.ncbi.nlm.nih.gov/entrez/ (Cited 15 Jan 2007)

  15. Rosholm JU, Bjerrum L, Hallas J, Worm J, Gram LF (1998) Polypharmacy and the risk of drug-drug interactions among Danish elderly. A prescription database study. Dan Med Bull 45(2):210–213

    PubMed  CAS  Google Scholar 

  16. Rothman KJ (1986) Modern epidemiology. Little, Brown, Boston, Toronto

    Google Scholar 

  17. Sjöqvist F (1997) A new classification system of drug interactions. Eur J Clin Pharmacol 52[Suppl]: abstract 377

  18. Tamblyn RM, McLeod PJ, Abrahamowicz M, Laprise R (1996) Do too many cooks spoil the broth? Multiple physician involvement in medical management of elderly patients and potentially inappropriate drug combinations. Can Med Assoc J 154(8):1177–1184

    CAS  Google Scholar 

  19. WHO (World Health Organization) ATC Index (Cited 8 Jan 2007). Available from: http://www.whocc.no/atcddd/

  20. Westerlund LT, Bjork HT (2006) Pharmaceutical care in community pharmacies: practice and research in Sweden. Ann Pharmacother 40(6):1162–1169

    Article  PubMed  Google Scholar 

  21. Wettermark B, Hammar N, Fored CM, Leimanis A, Otterblad Olausson P, Bergman U et al. (2006) The new Swedish Prescribed Drug Register – opportunities for pharmacoepidemiological research and experience from the first six months. Pharmacoepidemiol Drug Safe (Published online DOI 10.1002/pds.1294

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Acknowledgements

This study could not have been conducted without the visionary initiatives in Jämtland more than 30 years ago by Göran Boethius and Folke Wiman, and the continuous work since. We are also indebted to Apoteket AB for financially supporting and hosting of the database and making it available for our study. Thanks also to Sten-Erik Öhlund for developing the interaction detection software.

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Authors and Affiliations

  1. E-Health Institute, University of Kalmar, Bredbandet 1, SE 392 30, Kalmar, Sweden

    Emelie Åstrand & Göran Petersson

  2. Apoteket AB and School of Pure and Applied Natural Sciences, University of Kalmar, Kalmar, Sweden

    Bengt Åstrand

  3. The Association of Pharmaceutical Industry, Stockholm, Sweden

    Karolina Antonov

Authors
  1. Emelie Åstrand
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  2. Bengt Åstrand
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  3. Karolina Antonov
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  4. Göran Petersson
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Corresponding author

Correspondence to Emelie Åstrand.

Additional information

An erratum to this article can be found at http://dx.doi.org/10.1007/s00228-007-0374-5

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Åstrand, E., Åstrand, B., Antonov, K. et al. Potential drug interactions during a three-decade study period: a cross-sectional study of a prescription register. Eur J Clin Pharmacol 63, 851–859 (2007). https://doi.org/10.1007/s00228-007-0326-0

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  • DOI: https://doi.org/10.1007/s00228-007-0326-0

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