Abstract
The aim of the present study was to clarify whether cognitive impairments caused by benzodiazepines (BDZs) are a consequence of their specific direct effects on cognitive function or whether they are explained as secondary effects of increased sleepiness. Ten healthy men (mean age, 33.9 years) participated in two experimental sessions in a randomized cross-over, double-blind study: in one session subjects were given a placebo and in the other they were given 0.125 mg triazolam (TRZ). Each experimental session was conducted on 1 day. After a pre-drug EEG recording and an event-related potential (ERP) recording, under an oddball paradigm, subjects took the TRZ or placebo orally at 1000 hours. Thereafter, EEG and ERP recording sessions, following the same procedure as the pre-drug sessions, were conducted at 1, 2, 4, 6 and 8 h after drug administration. The EEG and ERP recordings from Cz and Pz referred to the bilaterally linked ear electrodes were used. We found that P300 latency was significantly prolonged in TRZ condition at 2 h (Pz) and 4 h (Cz and Pz) after TRZ, and that the P300 amplitude was significantly reduced at 2 h (Cz and Pz) and 4 h (Pz) after TRZ, compared to the same times after placebo. The absolute power values for the theta (4–7 Hz), alpha 1 (8–9 Hz), and alpha 2 (10–12 Hz) bands did not differ at any measurement time between the treatments. Only the beta band (13–19 Hz) power value was significantly elevated after the TRZ administration (versus placebo). No significant sedative effects were detected in subjective measurements. These results indicate that a single oral dose of 0.125 mg TRZ caused cortical changes without distinct general sedation or subjective sleepiness.
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References
Barbee JG (1983) Memory, benzodiazepine and anxiety; integration of theoretical and clinical perspectives. J Clin Psychiatry 54 [suppl]:86–97
Berchou R, Chayasirisobhon S, Green V, Mason K (1986) The pharmacodynamic properties of lorazepam and methylphenidate drugs on event-related potentials and power spectral analysis in normal subjects. Clin Electroencephalogr 17:176–180
Bixler EO, Kales A, Manfredi RL, Vgontzas AN, Tyson KL, Kales JD (1991) Next-day memory impairment with triazolam use. Lancet 337:827–831
Curran HV, Schiwy W, Lader M (1991) Benzodiazepines, memory and mood: a review. Psychopharmacological 105:1–8
Dixon WJ, Tukey W (1968) Approximate behavior of the distribution of winzorizedt (Trimming/Winsorization 2). Technometrics 10:49–53
Fujiwara R, Niiyama Y, Sato N, Abe M, Hishikawa Y (1991) Effects of triazolam and flunitrazepam on event-related potentials (ERPs). Ann Rep Phamacopsychiatr Res Found 22:34–41
Greenblatt DJ (1992) Pharmacology of benzodiazepine hypnotics. J Clin Psychiatry 53 [suppl]:7–13
Hennessy MJ, Kirkby KC, Montgomery IM (1991) Comparison of the amnesic effects of midazolam and diazepam. Psychopharmacology 103:545–550
Hermann WM, Schaerer E (1986) Computer EEG analysis to describe the projection of drug effects on a functional cerebral level in humans. In: da Silver FHL, van Leemen WS, Remond A (eds) Handbook of EEG and neurophysiology, vol. 2. Clinical application of computer analysis of EEG and other neurophysiological signals. Elsevier, Amsterdam, pp 385–445
Johnson LC, Chernik DA (1982) Sedative-hypnotic and human performance. Psychopharmacology 76:101–113
Matousek M, Petersen I (1979) Automatic measurement of the vigilance level and its possible application in psychopharmacology. Pharmacopsychiatry 12:148–154
Milliggam KR, Lumsden J, Howard RC, Howe JP, Dundee JW (1989) Use of auditory evoked responses as a measure of recovery from benzodiazepine sedation. J R Soc Med 82:595–597
Münte TF, Heinze HJ, Künkel H (1986) Use of endogenous event-related potentials (ERP) in the evaluation of psychotropic substances towards on ERP profile of drug effects. Neuropsychobiol 16:135–145
Okawa M, Matousek M, Petersen I (1984) Spontaneous vigilance fluctuations in the daytime. Psychophysiology 21:207–211
Rockstroh B, Elbert T, Lutzenberger W, Altenmüller E (1991) Effects of the anticonvulsant benzodiazepine clonazepam on event-related brain potentials in humans. Electroencephalogr Clin Neurohysiol 78:142–149
Rothschild AJ (1992) Disinhibition, amnestic reactions, and other adverse reactions secondary to triazolam. A review of the literature. J Clin Psychiatry 53 (suppl):69–79
Shimokochi M, Okita H, Satoh K, Shibasaki H, Nakanishi T, Hashimoto I (1985) Official report of the committee on methodology of evoked potential: Japanese Society of EEG and EMG. Jpn J EEG EMG 13:97–104
Shinotoh H, Iyo M, Yamada T, Inoue O, Suzuki K, Itoh T, Fukuda H, Yamasaki T, Tateno Y, Hirayama K (1989) Detection of benzodiazepine receptor occupancy in the human brain by positron emission tomography. Psychopharmacology 99:202–207
Spiegel R, Aebi HJ (1983) Methods for recording subjective drug effects. In: Spiegel R, Aebi HJ (eds) Psychopharmacology an introduction. John Wiley, Chichester, pp 49–53
Van der Kroef C (1979) Reactions to triazolam. Lancet 2:526
Wysowski DK, Baum C (1991) Outpatient use of prescription sedative-hypnotic drugs in the United States, 1970 through 1989. Arch Int Med 151:1779–1783
Yamadera H, Ferber G, Matejcek M, Pokorny R (1985) Electroencephalographic and psychometric assessment of the CNS effects of single doses of guanfacine hydrochloride (Estulic) and clonidine (Catapres). Neuropsychobiology 14:97–107
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Urata, J., Enomoto, T., Hayakawa, T. et al. Effects of a small dose of triazolam on P300 and resting EEG. Psychopharmacology 125, 179–184 (1996). https://doi.org/10.1007/BF02249418
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DOI: https://doi.org/10.1007/BF02249418