Efforts to increase awareness of potential drug interactions is needed. Although community pharmacies are adequately equipped with computerized drug interaction surveillance systems this is often not applied to self-medication. Vigilance for potential interactions of all drugs, including those sold over the counter, should be increased.

Pharmacists override a substantial proportion of drug-interaction alerts of minor or moderate potential severity by ignoring them or by programming the system to only flag drug interactions of potentially high severity. More sophisticated systems with improved sensitivity and specificity are required. Until these become available, it is important to ensure that at least potentially severe drug interactions are not missed; a goal that seems to be largely achieved.

Objective To analyze the current drug-interaction management in Swiss community pharmacies, with a particular focus on electronic systems, and to compare the results with those expressed by German general practitioners in a recent survey. Methods Data were collected with a postal questionnaire which was randomly sent to 500 out of 833 community pharmacies in the German part of Switzerland. Results The response rate was 57.4%, and only 24.7% pharmacists reported that they were confronted less than daily with potential drug interactions. Use of computer software to identify potential drug interactions was widespread in community pharmacies (90.2%), and the software was the primary source of information (81.2±29.6%). The quality of the interaction software was judged sensitive (identifying all dangerous interactions) by 80.5±21.5%, but specific (identifying only relevant interactions) by only 38.3±32%. Pharmacists declared a low override rate (14%) of drug interaction alerts, although unjustified alerts were reported by 60.6±33.1%. In contrast to general practitioners, pharmacists opted less often for information on the mechanism of the interaction, and more frequently for details for dose adjustment. Both groups complained about deficient information on non-interacting alternatives. Conclusion The information needs of community pharmacists differed considerably from general practitioners, and pharmacists were overwhelmed by inappropriate alerts because of a lack of specificity of their drug-interaction systems. Substantial improvement of drug-interaction software systems is thus required at least in two important aspects, the suppression of inappropriate alerts and the tailoring to the needs of the user.

Risk factors associated with a high velocity of the development of hyperkalaemia are use of potassium supplements>severe renal impairment>use of ACE inhibitors or ARBs>use of potassium-sparing diuretics>diabetes mellitus. The presence of two or more of these risk factors is associated with an even faster development of hyperkalaemia. Clinicians should be aware of these risk factors in order to avoid a rapid development of potentially life-threatening hyperkalaemia.