THE NEUROTOXICITY SCALE - THE VALIDITY OF A PATIENT-BASED SCALE, ASSESSING NEUROTOXICITY

The validity of a patient-based scale, presumably measuring adverse ef fects of drugs on cognitive function, was examined in a normal volunte er study. Thirty subjects were randomly assigned to placebo or one of two doses of a benzodiazepine, temazepam (10 mg and 20 mg), in a doubl e-blind placebo-controlled parallel group design. Plasma samples were taken before the scale was completed and up to 8 hours post-dose. Afte r administration of the medication the subjects were asked to maintain their normal daily routine as much as possible (reading, studying, co nversations). The inventory was administered twice, at 50 minutes and 2 hours post-dose (peak level). The overall score was different betwee n the three groups, only for the second assessment, 2 h post-dose (ANO VA, P < 0.02). Multiple t-testing between the three groups revealed st atistically significant differences between placebo and the 10 mg tema zepam group (P = 0.02) and between placebo and the 20 mg temazepam gro up (P = 0.006). No significant difference was found between the two te mazepam groups. Analysis of the separate questions showed least sensit ivity for questions related to the domain of 'hyperexcitability' and m ost sensitivity for 'fatigue' and 'slowing.' The overall score appeare d to be sensitive already for the lower toxicity range suggesting an ' all or nothing effect'. The subjective reports, collected by using thi s scale, may therefore be used for the detection of gross overall chan ges in cognitive functioning.