Potential drug–drug interactions in patients with cardiovascular diseases: findings from a prospective observational study
Abstract
Background: Patients with cardiovascular diseases (CVD) are at high risk of experiencing drug–drug interactions
(DDIs). The objective of this study was to evaluate the frequency, level and risk factors associated with potential-DDIs
(pDDIs) in hospitalized CVD patients at cardiology departments of two tertiary care hospitals in Quetta, Pakistan.
Methods: In the current prospective observational study, a total of 300 eligible CVD inpatients were evaluated for
pDDIs using Lexicomp Interact®. The pDDIs were classifed into class A (no known interaction); B (no action needed);
C (monitor therapy: it is documented that the benefts of an interaction outweigh the risk, appropriately monitor
therapy in order to avoid potential adverse outcomes); D (consider therapy modifcation: it is documented that proper
actions must be taken to reduce the toxicity resulting from an interaction); X (avoid combination: the risk of an interaction outweighs the benefts and are usually contraindicated). Multivariate binary logistic regression analysis was
used to fnd factors associated with the presence of Class-D and/or X pDDIs. A p-value<0.05 was considered statistically signifcant.
Results: With a median of 8.50 pDDIs per patient, all patients (100%) had≥1 pDDIs. Out of total 2787 pDDIs
observed, 74.06% (n=2064) were of moderate and (n=483) 17.33% of major severity. Class C pDDIs were most
common (n=1971, 70.72%) followed by D (n=582, 20.88%), B (n=204, 7.32%) and X (n=30, 1.08%). Sufering from
cardiovascular diseases other than myocardial infarction (OR 0.053, p-value<0.001) and receiving>12 drugs (OR 4.187,
p-value=0.009) had statistical signifcant association with the presence of class D and/or X pDDIs.
Conclusion: In the current study, pDDIs were highly prevalent. The inclusion of DDI screening tools, availability of
clinical pharmacists and paying special attention to the high-risk patients may reduce the frequency of pDDIs at the
study sites