We report a case of fatal internal haemorrhage in an elderly man who consumed only cranberry juice for two weeks while maintaining his usual dosage of warfarin. We propose that naturally occurring compounds such as flavonoids, which are present in fruit juices, may increase the potency of warfarin by competing for the enzymes that normally inactivate warfarin. While traditionally regarded as foodstuffs, consumption of fruit juices should be considered when patients develop adverse drug reactions.

the clinical problem Many patients claim to be allergic to penicillin. For those confirmed as being truly allergic (type 1 allergy, with features of urticaria, pruritic rash, etc), the cited overall rate of 10% cross reactivity between penicillin and cephalosporins is an overestimate. 1 For life threatening infections in which a non-cephalosporin antibiotic would be suboptimal, consider giving a second or third generation cephalosporin: ceftriaxone, cefotaxime, cefuroxime, ceftazidime, as clinically appropriate.

Prescribers seek to provide their patients with access to the latest innovations in medicine to maximize their health status. When a new drug comes to market, it often has not been as widely tested as other available therapies, and its effectiveness and safety cannot be fully evaluated. To address this problem, physicians can use the STEPS (Safety, Tolerability, Effectiveness, Price, and Simplicity) mnemonic to provide an analytic framework for making better decisions about a new drug's appropriate place in therapy. A key element is to base this evaluation on patient-oriented evidence rather than accept disease-oriented evidence (which may be misleading), while avoiding inappropriate reliance on studies that report only noninferiority results or relative-risk reductions. The primary question to ask for each new drug prescribing decision is, "Is there good evidence that this new drug is likely to make my patient live longer or better compared with the available alternatives?"