Joris C. Verster
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Research Interests
Joris C. Verster has a total of 23 co-authors. Here are the top co-authors by number of shared publications:
Edmund R. Volkerts
7 shared publicationsDieuwke S. Veldhuijzen
3 shared publicationsAlain Patat
2 shared publicationsMarinus N. Verbaten
Utrecht University
2 shared publicationsA. Marit de Weert
Utrecht University
1 shared publicationAntonia H. C. M. L. Schreuder
1 shared publication
Latest Publications
- 1 June 2006
- Published by Wolters Kluwer Health in The Clinical Journal of Pain
- Vol. 22 (5) , 499-504
Effects of an Opioid (Oxycodone/Paracetamol) and an NSAID (Bromfenac) on Driving Ability, Memory Functioning, Psychomotor Performance, Pupil Size, and Mood
It has been suggested that driving a car is relatively safe when the driver is treated with nonsteroid anti-inflammatory drugs than when he or she is treated with opioid analgesics. However, the evidence for this statement is scarce. The objective of this study was to determine the effects of a nonsteroid anti-inflammatory drug (bromfenac 25 mg and 50 mg) and an opioid (oxycodone/paracetamol 5/325 mg and 10/650 mg), and placebo on driving ability, memory functioning, psychomotor performance, pupil size, and mood. Out of 30 healthy volunteers, 18 completed this randomized, double-blind, placebo-controlled crossover study, before the study had to be stopped due to bromfenac being pulled out from the market. One hour after administration of the drugs, the participants performed a standardized driving test during normal traffic. Thereafter, driving quality, mental effort and mental activation during driving were assessed. A laboratory test battery was performed 2.5 hours after administration of the drug. Visual analog scales assessing mood and pupil measurements were performed on several occasions during each test day. Both analgesics did not significantly affect performance in any test. However, volunteers reported that significantly more effort was needed to perform the driving test when treated with oxycodone/paracetamol, and that they experienced increased sedation and reduced alertness. Also, the pupil size was significantly decreased. In contrast, subjective assessments after both doses of bromfenac matched that of placebo. No significant impairment in behavior was found in the volunteers for both bromfenac and oxycodone/paracetamol. The lack of impairment from oxycodone/paracetamol may have been related to the participants reporting increased effort during driving while under the influence of this drug.
- 1 June 2006
- Published by Wolters Kluwer Health in The Clinical Journal of Pain
- Vol. 22 (5) , 499-504
Effects of an Opioid (Oxycodone/Paracetamol) and an NSAID (Bromfenac) on Driving Ability, Memory Functioning, Psychomotor Performance, Pupil Size, and Mood
It has been suggested that driving a car is relatively safe when the driver is treated with nonsteroid anti-inflammatory drugs than when he or she is treated with opioid analgesics. However, the evidence for this statement is scarce. The objective of this study was to determine the effects of a nonsteroid anti-inflammatory drug (bromfenac 25 mg and 50 mg) and an opioid (oxycodone/paracetamol 5/325 mg and 10/650 mg), and placebo on driving ability, memory functioning, psychomotor performance, pupil size, and mood. Out of 30 healthy volunteers, 18 completed this randomized, double-blind, placebo-controlled crossover study, before the study had to be stopped due to bromfenac being pulled out from the market. One hour after administration of the drugs, the participants performed a standardized driving test during normal traffic. Thereafter, driving quality, mental effort and mental activation during driving were assessed. A laboratory test battery was performed 2.5 hours after administration of the drug. Visual analog scales assessing mood and pupil measurements were performed on several occasions during each test day. Both analgesics did not significantly affect performance in any test. However, volunteers reported that significantly more effort was needed to perform the driving test when treated with oxycodone/paracetamol, and that they experienced increased sedation and reduced alertness. Also, the pupil size was significantly decreased. In contrast, subjective assessments after both doses of bromfenac matched that of placebo. No significant impairment in behavior was found in the volunteers for both bromfenac and oxycodone/paracetamol. The lack of impairment from oxycodone/paracetamol may have been related to the participants reporting increased effort during driving while under the influence of this drug.
- 1 January 2006
- Published by Bentham Science Publishers Ltd. in Current Drug Safety
- Vol. 1 (1) , 63-71
Hypnotics and Driving Safety: Meta-Analyses of Randomized Controlled Trials Applying the on-the-Road Driving Test
Background: Many people who use hypnotics are outpatients and are likely to drive a car the day after drug intake. The purpose of these meta-analyses was to determine whether or not this is safe. Methods: Placebo-controlled, randomized, double-blind trials were selected if using the on-the-road driving test to determine driving ability the day following one or two nights of treatment administration. Primary outcome measure of the driving test was the Standard Deviation of Lateral Position (SDLP); i.e., the weaving of the car. Fixed effects model meta-analyses were performed. Effect size (ES) was computed using mean standardized (weighted) difference scores between treatment and corresponding placebo SDLP values. Results: Ten studies, published from 1984 to 2002 (207 subjects), were included in the meta-analyses. The morning following bedtime administration, i.e. 10-11 hours after dosing, significant driving impairment was found for the recommended dose of various benzodiazepine hypnotics (ES=0.42; 95% Confidence Interval (CI)=0.14 to 0.71). Twice the recommended dose impaired driving both in the morning (ES=0.68; CI=0.39 to 0.97) and afternoon, i.e. 16-17 hours after dosing (ES=0.57; CI=0.26 to 0.88). Zopiclone 7.5 mg also impaired driving in the morning (ES=0.89; CI=0.54 to 1.23). Zaleplon (10 and 20 mg) and zolpidem (10 mg) did not affect driving performance the morning after dosing. Following middle-of-the-night administration, significantly impaired driving performance was found for zopiclone 7.5 mg (ES=1.51, CI=0.85 to 2.17), zolpidem 10 mg (ES=0.66, CI=0.13 to 1.19) and zolpidem 20 mg (ES=1.16, CI=0.60 to 1.72). Zaleplon (10 and 20 mg) did not affect driving performance. Conclusions: The analyses show that driving a car the morning following nocturnal treatment with benzodiazepines and zopiclone is unsafe, whereas the recommended dose of zolpidem (10 mg) and zaleplon (10 mg) do not affect driving ability.
- 1 January 2006
- Published by Bentham Science Publishers Ltd. in Current Drug Safety
- Vol. 1 (1) , 63-71
Hypnotics and Driving Safety: Meta-Analyses of Randomized Controlled Trials Applying the on-the-Road Driving Test
Background: Many people who use hypnotics are outpatients and are likely to drive a car the day after drug intake. The purpose of these meta-analyses was to determine whether or not this is safe. Methods: Placebo-controlled, randomized, double-blind trials were selected if using the on-the-road driving test to determine driving ability the day following one or two nights of treatment administration. Primary outcome measure of the driving test was the Standard Deviation of Lateral Position (SDLP); i.e., the weaving of the car. Fixed effects model meta-analyses were performed. Effect size (ES) was computed using mean standardized (weighted) difference scores between treatment and corresponding placebo SDLP values. Results: Ten studies, published from 1984 to 2002 (207 subjects), were included in the meta-analyses. The morning following bedtime administration, i.e. 10-11 hours after dosing, significant driving impairment was found for the recommended dose of various benzodiazepine hypnotics (ES=0.42; 95% Confidence Interval (CI)=0.14 to 0.71). Twice the recommended dose impaired driving both in the morning (ES=0.68; CI=0.39 to 0.97) and afternoon, i.e. 16-17 hours after dosing (ES=0.57; CI=0.26 to 0.88). Zopiclone 7.5 mg also impaired driving in the morning (ES=0.89; CI=0.54 to 1.23). Zaleplon (10 and 20 mg) and zolpidem (10 mg) did not affect driving performance the morning after dosing. Following middle-of-the-night administration, significantly impaired driving performance was found for zopiclone 7.5 mg (ES=1.51, CI=0.85 to 2.17), zolpidem 10 mg (ES=0.66, CI=0.13 to 1.19) and zolpidem 20 mg (ES=1.16, CI=0.60 to 1.72). Zaleplon (10 and 20 mg) did not affect driving performance. Conclusions: The analyses show that driving a car the morning following nocturnal treatment with benzodiazepines and zopiclone is unsafe, whereas the recommended dose of zolpidem (10 mg) and zaleplon (10 mg) do not affect driving ability.
- 1 August 2004
- Published by Elsevier in Sleep Medicine Reviews
- Vol. 8 (4) , 309-325
Residual effects of sleep medication on driving ability
- 1 August 2004
- Published by Elsevier in Sleep Medicine Reviews
- Vol. 8 (4) , 309-325
Residual effects of sleep medication on driving ability
- 1 April 2004
- Published by Springer Nature in Neuropraxis
- Vol. 8 (2) , 34-38
Het meten van rijvaardigheid in het normale verkeer: de effecten van hypnotica
- 1 April 2004
- Published by Springer Nature in Neuropraxis
- Vol. 8 (2) , 34-38
Het meten van rijvaardigheid in het normale verkeer: de effecten van hypnotica
- Open Access
- 1 March 2004
- Published by Wiley in CNS Drug Reviews
- Vol. 10 (1) , 45-76
Clinical Pharmacology, Clinical Efficacy, and Behavioral Toxicity of Alprazolam: A Review of the Literature
Alprazolam is a benzodiazepine derivative that is currently used in the treatment of generalized anxiety, panic attacks with or without agoraphobia, and depression. Alprazolam has a fast onset of symptom relief (within the first week); it is unlikely to produce dependency or abuse. No tolerance to its therapeutic effect has been reported. At discontinuation of alprazolam treatment, withdrawal and rebound symptoms are common. Hence, alprazolam discontinuation must be tapered.An exhaustive review of the literature showed that alprazolam is significantly superior to placebo, and is at least equally effective in the relief of symptoms as tricyclic antidepressants (TCAs), such as imipramine. However, although alprazolam and imipramine are significantly more effective than placebo in the treatment of panic attacks, Selective Serotonin Reuptake Inhibitors (SSRIs) appear to be superior to either of the two drugs. Therefore, alprazolam is recommended as a second line treatment option, when SSRIs are not effective or well tolerated.In addition to its therapeutic effects, alprazolam produces adverse effects, such as drowsiness and sedation. Since alprazolam is widely used, many clinical studies investigated its cognitive and psychomotor effects. It is evident from these studies that alprazolam may impair performance in a variety of skills in healthy volunteers as well as in patients. Since the majority of alprazolam users are outpatients, this behavioral impairment limits the safe use of alprazolam in patients routinely engaged in potentially dangerous daily activities, such as driving a car.
- 1 March 2004
- Published by Wiley in CNS Drug Reviews
- Vol. 10 (1) , 45-76
Open AccessClinical Pharmacology, Clinical Efficacy, and Behavioral Toxicity of Alprazolam: A Review of the Literature
Alprazolam is a benzodiazepine derivative that is currently used in the treatment of generalized anxiety, panic attacks with or without agoraphobia, and depression. Alprazolam has a fast onset of symptom relief (within the first week); it is unlikely to produce dependency or abuse. No tolerance to its therapeutic effect has been reported. At discontinuation of alprazolam treatment, withdrawal and rebound symptoms are common. Hence, alprazolam discontinuation must be tapered.An exhaustive review of the literature showed that alprazolam is significantly superior to placebo, and is at least equally effective in the relief of symptoms as tricyclic antidepressants (TCAs), such as imipramine. However, although alprazolam and imipramine are significantly more effective than placebo in the treatment of panic attacks, Selective Serotonin Reuptake Inhibitors (SSRIs) appear to be superior to either of the two drugs. Therefore, alprazolam is recommended as a second line treatment option, when SSRIs are not effective or well tolerated.In addition to its therapeutic effects, alprazolam produces adverse effects, such as drowsiness and sedation. Since alprazolam is widely used, many clinical studies investigated its cognitive and psychomotor effects. It is evident from these studies that alprazolam may impair performance in a variety of skills in healthy volunteers as well as in patients. Since the majority of alprazolam users are outpatients, this behavioral impairment limits the safe use of alprazolam in patients routinely engaged in potentially dangerous daily activities, such as driving a car.
- 1 March 2004
- Published by Elsevier in Annals of Allergy, Asthma & Immunology
- Vol. 92 (3) , 294-304
Antihistamines and driving ability: evidence from on-the-road driving studies during normal traffic
- 1 March 2004
- Published by Elsevier in Annals of Allergy, Asthma & Immunology
- Vol. 92 (3) , 294-304
Antihistamines and driving ability: evidence from on-the-road driving studies during normal traffic
- 30 April 2003
- Published by Springer Nature in Psychopharmacology
- Vol. 169 (1) , 84-90
Driving ability after acute and sub-chronic administration of levocetirizine and diphenhydramine: a randomized, double-blind, placebo-controlled trial
Sedation following antihistamine use poses a danger to ambulant patients involved in daily activities such as driving.
- 30 April 2003
- Published by Springer Nature in Psychopharmacology
- Vol. 169 (1) , 84-90
Driving ability after acute and sub-chronic administration of levocetirizine and diphenhydramine: a randomized, double-blind, placebo-controlled trial
Sedation following antihistamine use poses a danger to ambulant patients involved in daily activities such as driving.
- 1 December 2002
- Published by Wolters Kluwer Health in Journal of Clinical Psychopharmacology
- Vol. 22 (6) , 576-583
Residual Effects of Middle-of-the-Night Administration of Zaleplon and Zolpidem on Driving Ability, Memory Functions, and Psychomotor Performance
Thirty healthy volunteers participated in this two-part study. Part 1 was a single-blind, two-period crossover design to determine the effects of a single dose of ethanol (0.03% < BAC < 0.05%) or ethanol-placebo on driving ability, memory, and psychomotor performance. Part 2 was a double-blind, five-period crossover design to measure the effects of a middle-of-the-night administration of zaleplon 10 or 20 mg, zolpidem 10 or 20 mg, or placebo on driving ability 4 hours after administration and memory and psychomotor performance 6 hours after administration. The on-the-road driving test consisted of operating an instrumented automobile over a 100-km highway circuit at a constant speed (95 km/h) while maintaining a steady lateral position between the right lane boundaries. The standard deviation of lateral position (SDLP) was the primary performance parameter of the driving test. The psychomotor and memory test battery consisted of the Word Learning Test, the Critical Tracking Test, the Divided Attention Test, and the Digit Symbol Substitution Test. Data for each part were analyzed separately using ANOVA for crossover designs. Zaleplon 10 and 20 mg did not significantly impair driving ability 4 hours after middle-of-the-night administration. Relative to placebo, after zolpidem 10 mg, SDLP was significantly elevated, but the magnitude of the difference was small and not likely to be of clinical importance. Memory and psychomotor test performance was unaffected after both doses of zaleplon and zolpidem 10 mg. In contrast, zolpidem 20 mg significantly increased SDLP and speed variability. Further, zolpidem 20 mg significantly impaired performance on all psychomotor and memory tests. Finally, driving performance, Digit Symbol Substitution Test, Divided Attention Test, and immediate and delayed free recall of the Word Learning Test were significantly impaired after ethanol. The results show that zaleplon (10 and 20 mg) is a safe hypnotic devoid of next-morning residual impairment when used in the middle of the night.
- 1 December 2002
- Published by Wolters Kluwer Health in Journal of Clinical Psychopharmacology
- Vol. 22 (6) , 576-583
Residual Effects of Middle-of-the-Night Administration of Zaleplon and Zolpidem on Driving Ability, Memory Functions, and Psychomotor Performance
Thirty healthy volunteers participated in this two-part study. Part 1 was a single-blind, two-period crossover design to determine the effects of a single dose of ethanol (0.03% < BAC < 0.05%) or ethanol-placebo on driving ability, memory, and psychomotor performance. Part 2 was a double-blind, five-period crossover design to measure the effects of a middle-of-the-night administration of zaleplon 10 or 20 mg, zolpidem 10 or 20 mg, or placebo on driving ability 4 hours after administration and memory and psychomotor performance 6 hours after administration. The on-the-road driving test consisted of operating an instrumented automobile over a 100-km highway circuit at a constant speed (95 km/h) while maintaining a steady lateral position between the right lane boundaries. The standard deviation of lateral position (SDLP) was the primary performance parameter of the driving test. The psychomotor and memory test battery consisted of the Word Learning Test, the Critical Tracking Test, the Divided Attention Test, and the Digit Symbol Substitution Test. Data for each part were analyzed separately using ANOVA for crossover designs. Zaleplon 10 and 20 mg did not significantly impair driving ability 4 hours after middle-of-the-night administration. Relative to placebo, after zolpidem 10 mg, SDLP was significantly elevated, but the magnitude of the difference was small and not likely to be of clinical importance. Memory and psychomotor test performance was unaffected after both doses of zaleplon and zolpidem 10 mg. In contrast, zolpidem 20 mg significantly increased SDLP and speed variability. Further, zolpidem 20 mg significantly impaired performance on all psychomotor and memory tests. Finally, driving performance, Digit Symbol Substitution Test, Divided Attention Test, and immediate and delayed free recall of the Word Learning Test were significantly impaired after ethanol. The results show that zaleplon (10 and 20 mg) is a safe hypnotic devoid of next-morning residual impairment when used in the middle of the night.
- 8 October 2002
- Published by Springer Nature in Neuropsychopharmacology
- Vol. 28 (4) , 740-746
Alcohol Hangover Effects on Memory Functioning and Vigilance Performance after an Evening of Binge Drinking
The impairing effects on memory functioning after acute alcohol intoxication in healthy volunteers and after chronic use in alcoholics are well established. However, research determining the next-morning effects of a single episode of binge drinking on memory functioning is scarce. A total of 48 healthy volunteers participated in a single-blind study comprising an evening (baseline) session, followed by a treatment administration (ethanol 1.4 g/kg or placebo), and a morning session. Memory was tested with a word-learning test (including immediate and delayed recall, and recognition). Further, a 45-min Mackworth clock test for measuring vigilance was included (parameters: number of hits and false alarms) and subjective alertness was assessed, to infer whether word-learning test findings reflect sedation or specific memory impairments. Delayed recall in the morning session was significantly worse in the alcohol group when compared to the placebo group (F1,42=6.0, p1,44=8.7, p1,44=13.3, p<0.001, respectively). However, in the Mackworth clock test, the alcohol group and placebo group did not differ significantly in the morning session. The specific findings of impaired delayed recall show that memory retrieval processes are significantly impaired during alcohol hangover. Vigilance performance was not significantly affected, indicating that this memory impairment does not reflect sedation.
- 8 October 2002
- Published by Springer Nature in Neuropsychopharmacology
- Vol. 28 (4) , 740-746
Alcohol Hangover Effects on Memory Functioning and Vigilance Performance after an Evening of Binge Drinking
The impairing effects on memory functioning after acute alcohol intoxication in healthy volunteers and after chronic use in alcoholics are well established. However, research determining the next-morning effects of a single episode of binge drinking on memory functioning is scarce. A total of 48 healthy volunteers participated in a single-blind study comprising an evening (baseline) session, followed by a treatment administration (ethanol 1.4 g/kg or placebo), and a morning session. Memory was tested with a word-learning test (including immediate and delayed recall, and recognition). Further, a 45-min Mackworth clock test for measuring vigilance was included (parameters: number of hits and false alarms) and subjective alertness was assessed, to infer whether word-learning test findings reflect sedation or specific memory impairments. Delayed recall in the morning session was significantly worse in the alcohol group when compared to the placebo group (F1,42=6.0, p1,44=8.7, p1,44=13.3, p<0.001, respectively). However, in the Mackworth clock test, the alcohol group and placebo group did not differ significantly in the morning session. The specific findings of impaired delayed recall show that memory retrieval processes are significantly impaired during alcohol hangover. Vigilance performance was not significantly affected, indicating that this memory impairment does not reflect sedation.
- 1 August 2002
- Published by Springer Nature in Neuropsychopharmacology
- Vol. 27 (2) , 260-269
Effects of Alprazolam on Driving Ability, Memory Functioning and Psychomotor Performance A Randomized, Placebo-controlled Study
Alprazolam is prescribed for the treatment of anxiety and panic disorder. Most users are presumably involved in daily activities such as driving. However, the effects of alprazolam on driving ability have never been investigated. This study was conducted to determine the effects of alprazolam (1 mg) on driving ability, memory and psychomotor performance. Twenty healthy volunteers participated in a randomized, double-blind, placebo-controlled crossover study. One hour after oral administration, subjects performed a standardized driving test on a primary highway during normal traffic. They were instructed to drive with a constant speed (90 km/h) while maintaining a steady lateral position within the right traffic lane. Primary performance measures were the Standard Deviation of Lateral Position (SDLP) and the Standard Deviation of Speed (SDS). After the driving test, subjective driving quality, mental effort, and mental activation during driving were assessed. A laboratory test battery was performed 2.5 h after treatment administration, comprising the Sternberg Memory Scanning Test, a Continuous Tracking Test, and a Divided Attention Test. Relative to placebo, alprazolam caused serious driving impairment, as expressed by a significantly increased SDLP (F(1,19) = 97.3, p <.0001) and SDS (F(1,19) = 30.4, p <.0001). This was confirmed by subjective assessments showing significantly impaired driving quality (F(1,19) = 16.4, p <.001), decreased alertness (F(1,19) = 43.4, p <.0001), decreased mental activation (F(1,19) = 5.7, p <.03) and increased mental effort during driving (F(1,19) = 26.4, p <.0001). Furthermore, alprazolam significantly impaired performance on the laboratory tests. In conclusion, alprazolam users must be warned not to drive an automobile or operate potentially dangerous machinery.
- 1 August 2002
- Published by Springer Nature in Neuropsychopharmacology
- Vol. 27 (2) , 260-269
Effects of Alprazolam on Driving Ability, Memory Functioning and Psychomotor Performance A Randomized, Placebo-controlled Study
Alprazolam is prescribed for the treatment of anxiety and panic disorder. Most users are presumably involved in daily activities such as driving. However, the effects of alprazolam on driving ability have never been investigated. This study was conducted to determine the effects of alprazolam (1 mg) on driving ability, memory and psychomotor performance. Twenty healthy volunteers participated in a randomized, double-blind, placebo-controlled crossover study. One hour after oral administration, subjects performed a standardized driving test on a primary highway during normal traffic. They were instructed to drive with a constant speed (90 km/h) while maintaining a steady lateral position within the right traffic lane. Primary performance measures were the Standard Deviation of Lateral Position (SDLP) and the Standard Deviation of Speed (SDS). After the driving test, subjective driving quality, mental effort, and mental activation during driving were assessed. A laboratory test battery was performed 2.5 h after treatment administration, comprising the Sternberg Memory Scanning Test, a Continuous Tracking Test, and a Divided Attention Test. Relative to placebo, alprazolam caused serious driving impairment, as expressed by a significantly increased SDLP (F(1,19) = 97.3, p <.0001) and SDS (F(1,19) = 30.4, p <.0001). This was confirmed by subjective assessments showing significantly impaired driving quality (F(1,19) = 16.4, p <.001), decreased alertness (F(1,19) = 43.4, p <.0001), decreased mental activation (F(1,19) = 5.7, p <.03) and increased mental effort during driving (F(1,19) = 26.4, p <.0001). Furthermore, alprazolam significantly impaired performance on the laboratory tests. In conclusion, alprazolam users must be warned not to drive an automobile or operate potentially dangerous machinery.