Pharmacy World & Science

, Volume 32, Issue 6, pp 815–821 | Cite as

The incidence of potential drug–drug interactions in elderly patients with arterial hypertension

  • Vesna Bacic-Vrca
  • Srecko MarusicEmail author
  • Viktorija Erdeljic
  • Slaven Falamic
  • Nives Gojo-Tomic
  • Dario Rahelic
Research Article


Objective To assess the incidence and type of potential, clinically significant drug–drug interactions in elderly outpatients with arterial hypertension. Setting Three community pharmacies in Croatia. Method Eligible patients were aged 65 or older, treated for arterial hypertension and received 2 or more drugs. Potential interactions were identified by Lexi-Interact software. The software categorized each potential interaction according to clinical significance in five groups: (A) No known interaction; (B) Specified agents may interact, but there is little to no evidence of clinical concern; (C) Specified agents may interact in a clinically significant manner. Monitoring therapy is suggested; (D) The two medications may interact in a clinically significant manner. Modification of therapy is suggested; (X) Contraindicated combination. Interactions of level C, D and X were considered clinically significant. Main outcome measure The incidence and type of potential drug–drug interactions. Results There were 265 patients included in the study. Potential, clinically significant drug interactions were identified in 240 (90.6%) patients, out of which 97.9% had interactions with clinical significance C, 20.4% D, and 0.8% X. The median number of drug interactions per patient was 4. We identified 215 drug combinations with the potential to cause clinically significant interaction, out of which 83.3% had clinical significance C, 16.3% clinical significance D, and 0.4% clinical significance X. Conclusion Drug–drug interactions are common in elderly hypertensive patients. Computer-based screening could help pharmacists and physicians to recognize potential, clinically significant interactions.


Arterial hypertension Croatia Drug–drug interactions Elderly Software 



The authors would like to thank Belic S., Kosovec-Hadwiger T. and Barlovic H. for their assistance with data extraction.


The study received no external funding.

Conflicts of interest

None of the authors of this manuscript had any conflict of interests in connection with this study.


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Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • Vesna Bacic-Vrca
    • 1
  • Srecko Marusic
    • 2
    Email author
  • Viktorija Erdeljic
    • 3
  • Slaven Falamic
    • 4
  • Nives Gojo-Tomic
    • 2
  • Dario Rahelic
    • 5
  1. 1.Department of Clinical PharmacyUniversity Hospital DubravaZagrebCroatia
  2. 2.Department of Clinical PharmacologyUniversity Hospital DubravaZagrebCroatia
  3. 3.Division of Clinical Pharmacology, Department of MedicineUniversity Hospital ZagrebZagrebCroatia
  4. 4.Community PharmacyDonji MiholjacCroatia
  5. 5.Department of MedicineUniversity Hospital DubravaZagrebCroatia

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