# Clinical Importance of Drug-Drug Interactions

> **NIH NIH R01** · UNIVERSITY OF PENNSYLVANIA · 2021 · $628,764

## Abstract

PROJECT SUMMARY
Drug-drug interactions (DDIs) must be regarded not only as a subject for pharmacoepidemiologists and clinical
pharmacologists, but as an important issue for public health, particularly in older adults confronted with multiple
chronic conditions. Known DDIs are responsible for 13% of adverse drug events and 4.8% of hospital
admissions in older adults. Even these high figures may understate the true impact of DDIs because they
include only the effects of known interactions. Many clinically important DDIs take years to discover. Given the
widespread and growing use of multiple medications by older adults, there is tremendous potential for DDIs to
occur in this population, especially among those treated with high risk therapies like warfarin or direct oral
anticoagulants. Based on known metabolic pathways, these anticoagulants may interact with many commonly-
prescribed medications. DDIs involving anticoagulants can cause over- or under-anticoagulation, the sequelae
of which can be immediately life-threatening and have long-term consequences.
The broad objective of this project is to produce clinically-actionable and biologically-relevant knowledge about
which drugs interact with anticoagulants to cause serious bleeding and/or thromboembolism, as well as the
time-course of such interactions and the subgroups most susceptible to these DDIs. We will achieve this
objective by taking a translational science approach to DDIs in which we 1) perform high-throughput simulation
of potential DDIs based on pharmacologic knowledge; 2) perform high-throughput screening of healthcare
data; and then 3) confirm (or refute) and elucidate selected high-probability DDIs in an independent population
by conducting in-depth pharmacoepidemiologic studies. This project will produce clinically-actionable
knowledge about which drugs interact with anticoagulants to cause serious bleeding and/or thromboembolism,
and generalizable biological knowledge about the drugs and pathways involved in these interactions.

## Key facts

- **NIH application ID:** 10127542
- **Project number:** 5R01AG025152-15
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Sean Hennessy
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $628,764
- **Award type:** 5
- **Project period:** 2006-09-15 → 2024-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10127542

## Citation

> US National Institutes of Health, RePORTER application 10127542, Clinical Importance of Drug-Drug Interactions (5R01AG025152-15). Retrieved via AI Analytics 2026-05-29 from https://api.ai-analytics.org/grant/nih/10127542. Licensed CC0.

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