Moderate alcohol consumption and adverse drug reactions among older adults

PURPOSE: To assess the effect of moderate alcohol consumption on Adverse Drug Reactions (ADRs) among older adults admitted to acute care hospitals and to examine the consistency of this effect across gender and age groups. METHODS: We used the GIFA (Italian Group of Pharmacoepidemiology in the Elderly) database, which includes information on patients admitted to 81 medical centers in Italy. For this study we examined exclusively the ADRs detected at hospital admission that were classified as definite or probable based on the Naranjo algorithm. RESULTS: Among 22,778 participants, 894 were found to have one or more ADRs (3.9%). Gastrointestinal complications (n = 210; 0.9% of the population) were the most frequent ADRs, followed by metabolic/endocrine (n = 156; 0.7%), dermatological/allergic (n = 102; 0.4%) and arrhythmic (n = 78; 0.3%) complications. Diuretics were the most frequent culprit drugs, followed by NSAIDs and digoxin. An ADR was recorded in 383/10,427 (3.7%) non-drinkers and in 511/12,351 (4.1%) moderate drinkers. After adjusting for potential confounders, moderate alcohol consumption was associated with a 24% increased risk of ADRs (OR 1.24; 95%CI: 1.08-1.43). This effect seemed more evident among women (OR 1.30; 95%CI: 1.09-1.55), than men (OR 1.14; 95%CI: 0.90-1.43), while it was similar across different age groups (< 65 years OR 1.28; 95%CI: 0.99-1.66; 65-79 years OR 1.22; 95%CI: 0.98-1.52; > or = 80 years OR 1.20; 95%CI: 0.93-1.56). Considering the most common ADRs, moderate alcohol users presented a significantly higher risk of drug-related headache (OR 3.89; 95%CI: 1.43-10.61) and metabolic/endocrine complications (OR 1.67; 95%CI: 1.19-2.33). CONCLUSIONS: Moderate alcohol intake is associated with an increased risk of ADRs; this effect seems more evident among women than men, and it does not differ across age groups.