[Recommended dosage adaptation based on renal function is not always sufficient to avoid betalactam antibiotics side effects].

The potential neurotoxicity of betalactam antibiotics are well-known and is frequently associated with drug accumulation in patients with renal failure since these antibiotics are eliminated mostly by kidneys. The regional center of pharmacovigilance of Amiens has collected since 10 years, 20 notifications of neurotoxicity induced by betalactam antibiotics. The series included eight women and 12 men. Mean age was 65 years (26-84). The drug accumulation hypothesis was strengthened in nine cases by assays of plasma levels residual concentrations. In 17 cases, betalactam antibiotics dosage was adapted to creatinin clearance in accordance to the Summary of the Product Characteristics' (SPC) recommendations. For several drugs, no adaptation to renal function was proposed by SPC. Dosage adaptation based only on renal function as it's recommended is not always efficient to avoid neurological side effects.