In accordance with previous studies, high paediatric use of antibiotics and of drugs for the respiratory tract was found, mostly considered to be on-label with regard to age and product information (5
In a US population-based study, around 56% of children <12 had used at least one medicinal product during the week preceding the study (17
). Whether our finding that more than 70% of young children had been prescribed a medicine in 2007 is in accordance with the US finding is not possible to assess because of different methodology.
The overall off-label rate of 13.5% found in this study was slightly lower compared to a previous Swedish study in paediatric outpatients in the Stockholm area, reporting an off-label rate of 20.7% (4
). This difference can be explained by fewer off-label categories and analysis of substances instead of medicinal products in the present study (4
). Still, the magnitude of off-label prescription is similar to that reported in other studies (4
The off-label proportion may have been underestimated as the present study was restricted to the most commonly dispensed drugs, although they represented more than 99% of all dispensed drugs. The excluded drugs probably comprised drugs dispensed for children with rare diseases. It is likely that several of those drugs had been prescribed off-label. However, even if all those rarely prescribed drugs had been classified as off-label, the off-label rate in the study would not have changed much. The lack of possibility to assess additional off-label categories such as dose and indication could also have resulted in an underestimation of the off-label proportion.
As data were retrieved from SPDR at the fifth ATC level, no off-label analysis could be performed regarding the formulation of the medicinal product, which also could have contributed to an underestimation of the off-label proportion.
Topically used drugs and sex hormones were associated with a high off-label proportion as also shown elsewhere (8
). However, sex hormones, mostly hormonal contraceptives, are perhaps not the most important in need of further paediatric research, because long clinical experience does not suggest different efficacy in the paediatric population. However, there is still a need for long-term safety follow-up. Topically used drugs, antidepressant drugs, hypnotics, cardiovascular drugs and different NSAIDs are considered in greater need of paediatric clinical studies as they represent important therapeutic areas in all paediatric age groups with very different dose requirement as also suggested by other investigators (8
). Antidepressive agents have been highlighted in adolescents as drugs with a different adverse drug reaction pattern compared to that seen in adults, supporting the need for more paediatric clinical research both on drug efficacy and on safety (18
As the present study, other studies on outpatient paediatric drug use have demonstrated that the most common reason for off-label classification is complete lack of paediatric information in the SmPC (4
). A similar finding was also reported in a recent prospective hospital-based study in Sweden (1