Analysis of interaction risks of patients with polypharmacy and the pharmacist interventions performed to solve them-A multicenter descriptive study according to medication reviews in Hungarian community pharmacies

Abstract

Objective: The study examined the Drug-Related Problems (DRPs) of patients with polypharmacy in 78 Hungarian community pharmacies, especially the interaction risks in terms of their clinical severity. Also, the objective was to analyze pharmacists' interventions to solve the identified interaction risks.

Methodology: The research was carried out in the framework of the training of specialist pharmacists at Semmelweis University, with the participation of 78 graduated pharmacists with the collaboration of 98 GPs. A total of 755 patients participated in pharmaceutical counseling which meant a medication review process. DRPs were uniformly categorized and the interventions were recorded by pharmacists, while a detailed analysis of interaction risks was performed by authors.

Results: A total of 984 DRPs were registered. The most common category of DRPs was the "non-quantitative safety problems" (62.6%). Interaction risk was the most common cause of DRPs (54.0%). The highest proportion of interaction risks were between two prescription drugs (66.7%). In 30.7% of interaction risks' cases, there was not known negative outcome. In contrast, it was recommended to modify the therapy in 14.9% of interaction risks. Acetylsalicylic acid (22.8%), acenocoumarol (17.7%), and diclofenac (13.9%) were the most common active substances which caused serious interaction risks. A total of 599 pharmacist interventions were used to solve the 531 interaction risks. Pharmacists notified the GPs about the problem in 28.4% of cases and they intervened without the GP in 63.1% of cases, most often with patient education (27.4%).

Conclusion: Medication review by community pharmacists is required for the safe medicine using of patients with polypharmacy, as a significant number of DRPs have been recorded. The incidence of interaction risks stood out. It is essential to develop a pharmaceutical guideline to properly classify the clinical relevance of interaction risks (e.g. according to high-risk active substances) and to increase the collaboration with GPs.

Fig 1. The procedure of pharmacist consultations during the first and the monthly follow-up sessions.

Fig 2. The distribution and order of occurrence of the underlying causes of drug-related problems.

DRP: Drug-Related Problem; n(DRP) = 984.

Fig 3. Frequency of interaction risks grouped by the competent healthcare professional providing the necessary intervention and a complete solution, and by the prescribing and dispensing category of the drugs involved.

Rx: Prescription drug; OTC: Over-the-counter medicine; Other: Other products (e.g. dietary supplements); n.a.: Not available; n = 531.

Fig 4. Distribution of interactions by UpToDate Lexiomp® risk classification grades [43].

A: No known interaction, B: No action needed, C: Monitor therapy, D: Consider therapy modification, X: Avoid combination; n.a.: Not available; n = 531.

Fig 5. Distribution of interactions by clinical risk caused by active substances causing the most Grade A/B or Grade D/X interactions.

5/A: Distribution of interactions by clinical risk caused by active substances causing the most Grade A/B interactions. 5/B: Distribution of interactions by clinical risk caused by active substances causing the most Grade D/X interactions. A: No known interaction; B: No action needed; C: Monitor therapy; D: Consider therapy modification; X: Avoid combination; n.a.: Not available.

Fig 6. The incidence of pharmacist interventions to solve interaction risks, in order of frequency.

GP: General practitioner; n = 599.

Fig 7. Proposal for a uniform pharmacy procedure for the management of interaction risks.