Potential drug-drug interactions in acute poisonings managed in the intensive care unit: occurrence, risk factors, and relationship to patient severity on admission.

Beyond the direct toxicity resulting from each drug in the poisoned patient, additional toxicities may result from drug-drug interactions (DDIs). We aimed to determine the frequency of potential DDIs in the poisoned patient and investigate whether DDIs are associated with severity. We conducted a 1-year cohort study in a toxicological ICU. DDIs were identified using an electronic interaction-checker tool. Among our 354 ICU poisoned patients, 134 (38%) presented at least one potential DDI between acute poisoning drugs and 180 (51%) at least one potential DDI between acute poisoning and long-term treatment drugs. Using multivariate analyses, previous suicide attempt was associated with the presence of potential DDIs between acute poisoning drugs in suicide attempt patients (P=.014). Chronic alcoholism (P=.005) and tobacco smoking (P=.022) were associated with the presence of potential DDIs between acute poisoning and long-term treatment drugs in recreational drug users. Presence of potential DDIs between acute poisoning and long-term treatment drugs was associated with catecholamine infusion (P=.022) in suicidal self-exposure patients. Presence of potential pharmacodynamic DDIs between acute poisoning and long-term treatment drugs was associated with aspiration pneumonia onset in recreational drug users (P=.03). ICU poisoned patients present a high rate of potential DDIs that may influence the outcome.