The use of drug level measurements in adult patients receiving theophylline, anti-epileptic drugs and amikacin.

This prospective study was conducted to determine how frequently measurement of drug levels was used in the management of adult patients receiving theophylline, phenytoin, phenobarbitone, carbamazepine or aminoglycosides in a large hospital. Fifty consecutive outpatients with asthma and 40 with epilepsy were interviewed and their records reviewed to determine which drugs had been prescribed and whether a level of the appropriate drug had been measured in the previous six months. Also, the records of 40 in-patients who were currently receiving amikacin were studied to determine whether serum levels had been measured at any stage during therapy with this drug. Serum theophylline levels were measured in only four (eight pc) patients who were taking this drug and were below the target range in two patients. Serum levels had been measured in 21 (52.5 pc) of 40 patients who were receiving 45 anti-epileptic drugs and were within the target in only nine. Serum amikacin levels were measured in 15 (37.5 pc) patients; blood had been taken for both peak and trough levels in 10 patients and found to exceed the target range in two patients. This study revealed that measurement of serum concentrations of theophylline, anti-epileptic drugs and amikacin was underutilised in the management of adult patients receiving these drugs at this hospital.