To the Editor.
—Although the article by Dr Schoenenberger and colleagues1 discusses the frequent inappropriateness of antiepileptic drug level monitoring, we suggest that habit and routine, more than diagnostic reasoning, often drive the physician's test requests of therapeutic drug monitoring. The fee-for-service policy of the National Health System in Italy greatly encourages drug monitoring for drugs such as quinidine for which the value of monitoring has not been established.2,3 Since the dosage of quinidine commonly used in Italy is low (400 to 600 mg per day), an eerie situation developed in all the clinical laboratories in which therepeutic monitoring of quinidine is carried out: its concentration rarely reaches the therapeutic interval (ie, 6 to 15 μmol/L [2 to 5 μg/mL]).3To measure this phenomenon, we collected the results of all quinidine assays obtained for inpatients and outpatients during different spans of time since 1990 in four hospital
Dorizzi RM, Dall'Olio G, Caputo M. Appropriateness of Antiepileptic Drug Level Monitoring. JAMA. 1996;275(10):757-758. doi:10.1001/jama.1996.03530340021018