ADR related questions received by a telephone medicines information service and ADRs received by a spontaneous ADR reporting system: a comparison regarding patients and drugs.

A telephone medicines information service (telephone service) has been available in the Netherlands since 1990. Patients can anonymously and free of charge ask a pharmacist all kinds of questions related to medication use. An analysis of the questions (n=7541) received by this service in 1994 showed that 28% of the questions predominantly related to adverse drug reactions (ADRs). A comparison was made between questions concerning ADRs received by the telephone service and suspected ADRs reported to the regionalized ADR reporting system LAREB regarding characteristics of the associated patients and medicines. In both systems approximately two out of three patients were women. LAREB received relatively more reports concerning patients of 60 years and older, whereas the telephone service received relatively more questions from patients aged 20-40 years. For most classes of medicines the observed proportion of encounters at both systems differed from the expected proportion estimated by the number of prescriptions in the same year. Antidepressants in particular were more frequently encountered at both systems than expected. There were clear differences between the telephone service and LAREB regarding the classes of medicines encountered. Reports of suspected ADRs submitted to LAREB more frequently involved antibiotics, antirheumatic products, anti-asthmatics, antihypertensives and topical antifungals, whereas questions concerning ADRs received by the telephone service significantly more frequently concerned drugs acting on the central nervous system (anxiolytics/hypnotics/sedatives, antidepressants and antipsychotic drugs) and corticosteroids. We are setting up further studies to investigate whether telephone services can serve as an additional tool in postmarketing surveillance for identifying potential drug safety issues. Copyright 1997 John Wiley & Sons, Ltd.