Uso de medicamentos nefrotóxicos em pediatria : prevalência, fatores de riscos e prevenção

Abstract

Kidneys are vulnerable to chemical agent-induced injuries. Children (neonates and infants) are a particular at risk age group because they have renal functions less developed than that of adults. The exposure of children to medicines considered to be nephrotoxic agents - namely the aminoglycosides, nonsteroidal anti-inflammatory drugs (NSAID) and angiotensin converting enzyme (ACE) inhibitory drugs - should be avoided whenever possible. Hospitalized children are pointed out to be the group at greatest risk of nephrotoxicity due to their high level of exposure to these medicines as well as the frequent and improper use of non standardized medicines in this age range. To determine the prevalence of use of potentially-nephrotoxic drugs (PND) and the frequency of concomitant risk factors in hospitalized children younger than 2 years old in a medical ward in a pediatric hospital in Fortaleza, Brazil. A prospective, observational, follow-up study was developed. All children younger than 2 years old admitted to the general ward were included and followed-up. Sociodemographic data, pathological and pharmacotherapeutic antecedents were recorded, as well as information about the use of drugs and the attendance of risk factors for nephrotoxicity associated with aminoglycosides, NSAID and ACE inhibitors. Also, the occurrence of adverse events was identified. Data was taken from medical records and interviews with the mothers of the children. Statistical analysis involved cumulative frequency, cumulative percentage, central tendency measures, Student “t” test and ANOVA. During the study period (September/2005 to March/2006), 120 admissions were recorded. Three patients were excluded because of incomplete data. The results represented 117 admissions that affected 103 different children. The prevalence of the use of PND was 96,6%. A total of 1065 drugs were used, 69% with potential intrinsic nephrotoxicity based on available literature. The mean number of PND used was 6,3 ± 4,0 per patient. The PND most frequently used were: metamizole (10,1%), ranitidine (6,2%) and prednisone (5,1%). Around 18% of children used aminoglycosides, 65,8% and 4,3% had taken NSAID and ACE inhibitory drugs respectively. A total of 368 risk factors for nephrotoxicity were detected (3,5±1,8 risk factors/patient). The most frequent factors were: the use of at least one PND (30,7%), the use of 2 or more PND (28,3%) and the use of NSAID concomitantly with that of potassium-rich salt substitutes(10%).The PND use was considered high when compared with published data from this studied age group. The frequency of risk factors for nephrotoxicity also reached considerable levels. It would be important to know if there exist safer therapeutic alternatives and what preventative measures could be adopted in each case. The contribution of a clinical pharmacist to a safe pharmacotherapy for hospitalized children would be a strategy for reducing PND-associated risk.