Key result
Preventive dose reduction of coumarin anticoagulants in co-trimoxazole users significantly reduced the risk of moderate overanticoagulation (OR 0.06) compared to no dose reduction, though it prolonged underanticoagulation.
Why the study?
Does preventive dose reduction of coumarin anticoagulants prevent overanticoagulation in patients taking co-trimoxazole compared to other antibiotics?
Observational (n=326)
Yes
Does preventive dose reduction of coumarin anticoagulants prevent overanticoagulation in patients taking co-trimoxazole compared to other antibiotics?
Odds Ratio: 0.06 (95% CI 0.01–0.51)
p-value: p=0.010
Preventive dose reduction of coumarins during co-trimoxazole therapy prevents overanticoagulation but leads to prolonged underanticoagulation, suggesting the combination should be avoided entirely.
No takes yet. Share an insight, caveat, or question.
May warrant avoiding co-trimoxazole with coumarins; leaves open optimal strategies pending randomized confirmation.
Schalekamp et al. (2007) conducted an observational in Stabilized on coumarin anticoagulants (acenocoumarol or phenprocoumon) requiring antibiotic therapy (n=326). Preventive dose reduction (PDR) of coumarin anticoagulant vs. No preventive dose reduction was evaluated on Moderate overanticoagulation (INR >4.5) (OR 0.06, 95% CI 0.01-0.51, p=0.010). Preventive dose reduction of coumarin anticoagulants in co-trimoxazole users significantly reduced the risk of moderate overanticoagulation (OR 0.06) compared to no dose reduction, though it prolonged underanticoagulation.
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