Differences in performance impairment due to brompheniramine maleate as a function of the sustained-release system

1 study examined whether different sustained release systems would cause variation in the effect of an antihistamine, brompheniramine maleate 10 mg, upon mood and psychomotor performance. Two commercial preparations were examined, one giving linear release (LR) of the drug over time, the other releasing the drug in a non-linear fashion (NLR). 2 Thirty-six males were allocated to four separate groups receiving either the drug with LR, drug with NLR, placebo or drug-free control. Single dosage of the drug occurred at 08.30 h and subjects completed mood inventories and performed serial choice reaction time and visual search tasks at 1 h, 2.75 h, 5.5 h and 7.25 h post dosage. 3 The NLR system significantly increased feelings of unco-ordination at 2.75 h and significantly slowed reaction time at both 2.75 and 5.5 h post dosage. The LR system significantly slowed reaction time only at 5.5 h but increased pausing in serial choice performance at that time. Neither system impaired visual search. 4 Results suggest that two preparations having identical active constituents may vary in their effects on psychomotor performance and mood as a function of their sustained release systems. A system giving linear release of the drug can reduce the early post-dosage performance decrement associated with a non-linear release system.