Psychomotor performance

It is estimated that concentrations of 3000 ppm cause unconsciousness in less than 10 minutes (39). Anesthetic effects have been reported at concentrations of 400 ppm after 20-min exposure. Decrease in psychomotor performance at a trichloroethylene concentration of 110 ppm has been reported in one study (33), whereas other studies find no neurotoxic effects at concentrations of 200 ppm (40—43). 

Cami J, FarreM, Mas M, etal. Human pharmacology of 3,4-methylenedioxymetham-phetamine ( ecstasy ) psychomotor performance and subjective effects. J Clin Psychopharmacol 20 455 66, 2000... 

External conditions can also cause a decrease in arousal that may also affect cognitive/psychomotor performance. An interesting stimulation study conducted by Suedfield and Eich136 showed how arousal can be reduced. They used Restricted Environmental Stimulation Technique (REST), in which a subject floats in a dense solution of skin temperature water and Epsom salts. This technique was shown to decrease subjective reports of arousal. Similar reports come from studies of meditation137-138 and systematic relaxation.139... 

Experimental demonstrations of the increments and decrements in arousal that can be produced by environmental conditions suggest a need to carefully examine this aspect of the literature concerned with the effects of caffeine on psychomotor performance. Variability in the environmental conditions and extraneous stimuli that differentiate experiments may have contributed substantially to the mixed results in that literature. Considerably more research, systematically varying environmental factors, and caffeine dosage levels will be needed before firm conclusions can be drawn in this area. 

Loke, W. H., Hinrichs, J. V., and Ghoneim, M. M., Caffeine and diazepam Separate and combined effects on mood, memory, and psychomotor performance. Psychopharmacology 87, 344-350, 1985. 

James JE (1994). Does caffeine enhance or merely restore degraded psychomotor performance Neuropsychobiology, 30, 124-125. 

Hindmarch I, Parrott AC and Lanza M (1979). The effects of ergot alkaloid derivative (Hydergine) on aspects of psychomotor performance, arousal, and cognitive processing ability. Journal of Clinical Pharmacology, 19, 726-732. 

Rigney U, Kimber S and Hindmarch I (1999). The effects of acute doses of standardised Ginkgo biloba extract on memory and psychomotor performance in volunteers. Phytotherapy Research, 13, 408 415. 

Rogers PJ, Richardson NJ and Dernoncourt C (1995) Caffeine use Is there a net benefit for mood and psychomotor performance Neuropsychobiology, 301, 194-199. 

Warot D, Lacomblez L, Danjou P, Weiller E, Payan C and Puech AJ (1991). Comparative effects of Ginkgo biloba extracts on psychomotor performances and memory in healthy subjects. Therapie, 46, 33-36. 

Zolpidem, chemically unrelated to benzodiazepines or barbiturates, acts selectively at the y-aminobutyric acidA (GABAA)-receptor and has minimal anxiolytic and no muscle relaxant or anticonvulsant effects. It is comparable in effectiveness to benzodiazepine hypnotics, and it has little effect on sleep stages. Its duration is approximately 6 to 8 hours, and it is metabolized to inactive metabolites. Common side effects are drowsiness, amnesia, dizziness, headache, and GI complaints. Rebound effects when discontinued and tolerance with prolonged use are minimal, but theoretical concerns about abuse exist. It appears to have minimal effects on next-day psychomotor performance. The usual dose is 10 mg (5 mg in the elderly or those with liver impairment), which can be increased up to 20 mg nightly. Cases of psychotic reactions and sleep-eating have been reported. 

V-desalkylflurazepam accounts for most of flurazepam s pharmacologic effects. This metabolite may help when daytime anxiety or early morning awakening is present, but daytime sedation with impaired psychomotor performance may occur. 

Caffeine improves psychomotor performance. For example, improvements are seen in manual dexterity (Bernstein et al. 1994). Enhancement of psychomotor performance is most evident when subjects are fatigued (Snyder and Sklar 1984). 

Bryant CA, Farmer A, Tiplady B, Keating J, Sherwood R, Swift CG, Jackson SH. (1998). Psychomotor performance investigating the dose-response relationship for caffeine and theophylline in elderly volunteers. EurJ Clin Pharmacol. 54(4) 309-13. 

Hindmarch I, Quinlan PT, Moore KL, Parkin C. (1998). The effects of black tea and other beverages on aspects of cognition and psychomotor performance. Psychopharmacology (Berlin). 139(3) 230-38. 

Rogers PJ, Dernoncourt C. (1998). Regular caffeine consumption a balance of adverse and beneficial effects for mood and psychomotor performance. Pharmacol Biochem Behav. 59(4) 1039-45. Rounsaville BJ, Anton SF, Carroll K, Budde D, Prusoff BA, Gawin F. (1991). Psychiatric diagnoses of treatment-seeking cocaine abusers. Arch Gen Psychiatry. 48(1) 43-51. 

Hindmarch I, Kerr JS, Sherwood N. (1990). Effects of nicotine gum on psychomotor performance in smokers and non-smokers. Psychopharmacology (Berlin). 100(4) 535-41. 

Perez-Reyes M, Hicks RE, Bumberry J, Jeffcoat AR, Cook CE. (1988). Interaction between marihuana and ethanol effects on psychomotor performance. Alcohol Clin Exp Res. 12(2) 268-76. 

Adult male volunteers were exposed to purified air,2 -2 - to ozone alone, or to ozone in combination with nitrogen dioxide and carbon monoxide. No additional effects were detected when nitrogen dioxide at 0.3 ppm was added to ozone. The addition of carbon monoxide at 30 ppm to the ozone-nitrogen dioxide mixture produced no additional effects, other than a slight increase in blood carboxyhemoglobin content and small decreases in psychomotor performance, which were not consistent in different subject groups. 

Allinson RH, Shirley AW, Smith G Threshold concentration of nitrous oxide affecting psychomotor performance. Br J Anesth 51 177-180, 1979... 

Venables H, Cherry N, Waldron HA, et al Effects of trace levels of nitrous oxide on psychomotor performance. Stand J Work Environ Health 9 391-396, 1983... 

The most common adverse effects are drowsiness, ataxia and reduced psychomotor performance. 

Benzodiazepines are generally well-tolerated (Table 1), although side-effects such as sedation, loss of balance and impaired psychomotor performance may be problematic for some patients. There are reported associations with road... 

Depressed CNS functioning (sedation, muscle weakness, light-headedness, confusion, ataxia, impaired psychomotor performance)... 

The longstanding use in some countries of hydroxyzine, a centrally-acting Hi-histamine receptor antagonist, is supported by positive findings in controlled trials in GAD (Ferreri and Hantouche 1998 Lader and Scotto 1998). Hydroxyzine promotes sleep and its anxiolytic effects have an early onset. Although it causes sedation, tolerance to this effect often occurs and effects on psychomotor performance are smaller than with benzodiazepines (de Brabander and Deberdt 1990). It is well-tolerated and withdrawal effects have not been reported. Although the evidence for its efficacy is not large, hydroxyzine provides an option for some patients with GAD for whom standard treatments are unsuitable. 

The most common adverse events associated with buspirone use include dizziness, headache, nausea, ner-vounsness, lightheadedness, and agitation. These adverse effects decrease over time. Buspirone does not cause seizures or abnormal involuntary movements or impair psychomotor performance. 

Buspirone. Several comparative studies of buspirone and benzodiazepines have reported comparable efficacy in reducing symptoms of anxiety. However, in contrast to benzodiazepines, buspirone is devoid of significant sedative or euphoric effects. Treatment with buspirone and other azaperones, such as gepirone, ipsapirone, and tandospirone, does not result in abuse, addiction, dependence, or withdrawal symptoms [Keppel Hesselink 1992). Buspirone also spares both cognitive and psychomotor performance [N. Sussman 1994). 

Preliminary phase II clinical data have shown that gepirone is an effective anxiolytic that significantly reduces both psychic and somatic symptoms of generalized anxiety disorder. Like buspirone, gepirone does not impair memory, verbal fluency, or psychomotor performance [Harto and Branconnier 1988]. 

The effects of THC and other cannabinoids on psychomotor performance are not easily summarized. There is clear impairment in most psychomotor tasks at high doses. The major conclusions that can be drawn are probably that moderate doses of THC have little effect on attention or on performance of very simple and well-practiced tasks. Furthermore, performance of complex tasks and tasks requiring complex processing of information is significantly Impaired by THC and other centrally active cannabinoids. 

Buspirone is a partial agonist at serotonin type 1A (5-HTj ) receptors. Unlike benzodiazepines, barbiturates, and alcohol, buspirone does not interact with the GABA receptor or chloride ion channels. Thus, it does not produce sedation, interact with alcohol, impair psychomotor performance, or pose a risk of abuse. There is no cross-tolerance between benzodiazepines and buspirone, so benzodiazepines cannot be abruptly replaced with buspirone. Likewise, buspirone cannot be used to treat alcohol or barbiturate withdrawal and detoxification. Like the antidepressants, buspirone has a relatively slow onset of action. 

The natural antidepressant hypericum perforatum is reported to have only few effects on cognitive and psychomotor performance in healthy volunteers after single doses of 900 and 1800mg only one test (DSST) within a large battery was significantly affected (Timoshanko et al., 2001). The effects of single doses of lithium on healthy volunteers are small. This also holds true when the substance is given over a period of several weeks. 

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