Arrhythmias & electrophysiology
Potential interactions between antimicrobials and direct oral anticoagulants: Population-based cohort and case-crossover study
Main finding · Gastrointestinal bleedingResult — go to the resultHazard ratio 3.66 99% CI 1.27–10.51Authors' conclusion
We found no strong evidence of increased risks of bleeding and cardiovascular outcomes in DOACs + clarithromycin/fluconazole/erythromycin users except a possible short-term increased risk of gastrointestinal bleeding in DOACs + erythromycin users.
Study context
- Population
- DOAC users in the Clinical Practice Research Datalink Aurum from January 1, 2011 to March 29, 2021coprescribed clarithromycin 21,701 · coprescribed erythromycin 4,532 · coprescribed fluconazole 4,840
- Participants
- 483,815 DOAC users
- Exposure
- Direct oral anticoagulants (DOACs) + clarithromycin/erythromycin/fluconazole users with DOACs users not receiving these antimicrobials
- DOAC + clarithromycinn = 21,701
- DOAC + erythromycinn = 4,532
- DOAC + fluconazolen = 4,840
- Outcome
- Gastrointestinal bleeding
- Follow-up
- 7 days following coprescription
Methodological details6-parameter case-crossover design
- 6-parameter case-crossover design
Main finding
As reported in the abstract
Hazard ratio
3.66
99% CI 1.27–10.51
DOAC + erythromycin vs DOAC alone
HR 3.66 (99% CI 1.27–10.51)
Observational data: associations, not effects.
Further findings
| Outcome | HR (99% CI) | |
|---|---|---|
| Cardiovascular mortalityDOAC + clarithromycin vs DOAC alone · cohort analysis | 3.36 (1.73–6.52) | |
| 0.10.31310Hazard ratio (log scale) |
Bleeding outcomes, DOAC + clarithromycin/fluconazole
- No evidence of increased risk of bleeding outcomes in cohort and case-crossover analyses
All-cause mortality
- Increased risk with DOAC + clarithromycin/erythromycin/fluconazole vs DOAC alone in cohort analysis
- Similar risks when initiating erythromycin/fluconazole with and without DOACs
Original publication
Potential interactions between antimicrobials and direct oral anticoagulants: Population-based cohort and case-crossover study. Heart Rhythm. Published 11 January 2025. doi:10.
Summarised from the published abstract; every number is checked against it