ABSTRACT
AIMS: The development of effective interventions to reduce inappropriate use of antibiotics in the elderly population requires knowledge on who can benefit from such interventions. Thus, we aimed to identify and characterise antibiotic heavy users among elderly patients in general practice with respect to sociodemographic variables. METHODS: We conducted a retrospective nationwide register-based study on all Danish elderly citizens (⩾65 years) who redeemed an antibiotic prescription in 2017. Heavy users were defined as the 10% with the highest excess use, that is, their recorded use minus the average use for their sex, age group and comorbidity level as estimated from a linear regression model. Comparative analyses of sociodemographic characteristics (civil status, employment status, urbanity, educational level and country of origin) of heavy users and non-heavy users were performed using logistic regression models. RESULTS: The study population consisted of 251,733 elderly individuals, who in total redeemed 573,265 prescriptions of antibiotics. Heavy users accounted for 68% of all excess use of antibiotics. In multivariable analyses, individuals with an educational level above basic schooling, non-retired, residing in an urban municipality and being born in a country outside Scandinavia all had lower odds of being a heavy user. Widowed, divorced or single individuals had higher odds of being a heavy user compared with married individuals. Relative importance analyses showed that civil status and educational level contributed considerably to the explained variance. CONCLUSIONS: This study found an association between sociodemographic characteristics and risk of being a heavy user, indicating that sociodemographic variation exists with regard to antibiotic prescribing.
ABSTRACT
PURPOSE: Azole antimycotics and nystatin oral solution are used to treat oral candidiasis. Azoles inhibit cytochrome (CYP) P450-dependent metabolism of warfarin, which could increase the anticoagulant effect of warfarin. Nystatin is not expected to interfere with warfarin metabolism, but current data are conflicting. With this study, we aimed to explore the potential drug-drug interactions between warfarin and azole antimycotics used in the treatment of oral candidiasis, that is, systemic fluconazole, miconazole oral gel, and nystatin oral solution. METHODS: By linking clinical data on international normalized ratio (INR) measurements with administrative data on filled prescriptions of warfarin and antimycotics during 2000-2015, we explored INR changes in warfarin users relative to initiation of systemic fluconazole (n = 413), miconazole oral gel (n = 330), and nystatin oral solution (n = 399). RESULTS: We found a significant increase in mean INR of 0.83 (95% confidence interval [CI] 0.61-1.04) and 1.27 (95% CI 0.94-1.59) following initiation of systemic fluconazole and miconazole oral gel, respectively. Also, the proportion of patients experiencing an INR-value above 5 was increased after initiation of fluconazole (from 4.3% to 15.3%) and miconazole (from 5.5% to 30.1%). INR was unaffected by initiation of nystatin oral solution (mean change 0.08; 95% CI -0.10 to 0.25). CONCLUSION: Initiation of systemic fluconazole and miconazole oral gel was associated with increased INR in warfarin users. A similar association was not found for nystatin oral solution, which thus appears to be the safest alternative when treating oral candidiasis in warfarin users.
