Correction: Prevalence of the Prescription of Potentially Interacting Drugs

Abstract

The use of multiple medications is becoming more common, with a correspondingly increased risk of untoward effects and drug-related morbidity and mortality. We aimed at estimating the prevalence of prescription of relevant potentially interacting drugs and at evaluating possible predictors of potentially interacting drug exposure. We retrospectively analyzed data on prescriptions dispensed from January 2004 to August 2005 to individuals of two Italian regions with a population of almost 2.1 million individuals. We identified 27 pairs of potentially interacting drugs by examining clinical relevance, documentation, and volume of use in Italy. Subjects who received at least one prescription of both drugs were selected. Co-prescribing denotes "two prescriptions in the same day", and concomitant medication "the prescription of two drugs with overlapping coverage". A logistic regression analysis was conducted to examine the predictors of potential Drug-Drug Interaction (pDDIs). 957,553 subjects (45.3% of study population) were exposed to at least one of the drugs/classes of the 27 pairs. Overall, pDDIs occurred 2,465,819 times. The highest rates of concomitant prescription and of co-prescription were for ACE inhibitors+NSAIDs (6,253 and 4,621/100,000 plan participants). Considering concomitance, the male/female ratio was <1 in 17/27 pairs (from 0.31 for NSAIDs-ASA+SSRI to 0.74 for omeprazole+clopidogrel). The mean age was lowest for methotrexate pairs (+omeprazole, 59.9 years; +NSAIDs-ASA, 59.1 years) and highest for digoxin+verapamil (75.4 years). In 13/27 pairs, the mean ages were ≥70 years. On average, subjects involved in pDDIs received ≥10 drugs. The odds of exposure were more frequently higher for age ≥65 years, males, and those taking a large number of drugs. A substantial number of clinically important pDDIs were observed, particularly among warfarin users. Awareness of the most prevalent pDDIs could help practitioners in preventing concomitant use, resulting in a better quality of drug prescription and potentially avoiding unwanted side effects.

Concomitant use of drugs known to cause interactions with oral antiplatelets—polypharmacy in acute coronary syndrome outpatients in Finland

“…These two interactions were the most common pharmacokinetic interactions among clopidogrel users with more than 6% of clopidogrel users for the two PPIs in our data. Also in an Italian cohort study, clopidogrelomeprazole pair was the most probable drug-drug interaction [16]. It might be potentially beneficial if omeprazole and esomeprazole would not be concomitantly used with clopidogrel [17].…”

Time-Trends of Drug-Drug Interactions among Elderly Outpatients in the Piedmont Region (Italy): A Population-Based Study

“…While the high risk of ADRs in the elderly has several causes, including frailty, comorbidities, and different degrees of physiological or pathological hepatic and renal impairment [ 8 , 9 ], a major and common determinant is due to polypharmacy. For example, the most recent Italian National drug report shows that the average drug consumption for the entire Italian population is approximately 1 defined daily dose (DDD) per inhabitant, but it rises to 2 in the 65–69 years-old patients and to 2.5 in the 70–74 years-old patients, exceeding a value of 3 in those over 75 years [ 10 ].…”