The effects of acute and repeated doses of zolpidem on subjective sleep,psychomotor performance and cognitive function in elderly volunteers

Summary We gave 24 healthy elderly volunteers with a perceived sleep onset of at least 30 minutes zolpidem 5 mg, zolpidem 10 mg, or placebo for 7 days in a double-blind, three-way, crossover study.The morning after nocturnal dosing, psychomotor performance and cognitive ability were measured using tests which are sensitive to the residual effects of hypnotics and to the effects of drugs on various indicators of sleep quality. The tests were: Choice Reaction Time; Tracking; Critical Flicker Fusion Threshold; Memory Scanning; Word Recognition; the Leeds Sleep Evaluation Questionnaire and Line Analogue Rating Scales.Zolpidem produced a subjective improvement in sleep but did not impair performance the following day. Furthermore, during repeated administration, there was no tolerance to the effects of sleep latency and quality of sleep, nor adverse effects on task performance.     

A double-blind, placebo-controlled investigation of the effects of fexofenadine, loratadine and promethazine on cognitive and psychomotor function

AIMS: To assess whether fexofenadine in a range of doses from 80 to 180 mg has any disruptive effects on aspects of psychomotor and cognitive function in comparison with placebo, loratadine and promethazine, an antihistamine known to produce psychomotor and cognitive impairment. METHODS: Twenty-four healthy volunteers received fexofenadine 80 mg, 120 mg and 180 mg, loratadine 10 mg, promethazine 30 mg (as a positive internal control) and placebo in a six-way crossover, double-blind study. Following each dose, subjects were required to perform a series of tests of cognitive function and psychomotor performance at 1.5, 3, 6, 9, 12 and 24 h post dose. The test battery included critical flicker fusion (CFF), choice reaction time (CRT) and assessment of subjective sedation (LARS). Overall levels of activity were monitored by means of wrist mounted actigraphs throughout each of the 24 h experimental periods. RESULTS: Fexofenadine at all doses tested was not statistically different from placebo in any of the tests used and loratadine did not cause any significant impairment of cognitive function. Significant impairments were found following promethazine. Promethazine caused a significant reduction in CFF threshold and this effect was evident up to 12 h post dose (P<0.05). There was a significant increase in recognition reaction time at 3 and 6 h post promethazine administration, and the drug caused a significant (P<0. 002) increase in the percentage of 'sleep-like' activity from actigraph records during the daytime. CONCLUSIONS: Fexofenadine at doses up to 180 mg appears free from disruptive effects on aspects of psychomotor and cognitive function in a study where the psychometric assessments have been shown to be sensitive to impairment, as evidenced by the effects of the verum control promethazine 30 mg.     

The effects of acute and repeated doses of moclobemide on psychomotor performance and cognitive function in healthy elderly volunteers

The effects of moclobemide, a new selective and reversible MAO-A inhibitor, on cognitive function and psychomotor performance were measured in 12 healthy elderly male volunteers (with a mean age of 72.5 years). Subjects received moclobemide 200 mg, amitriptyline (positive internal control) 25 mg or placebo twice daily and were assessed on a battery of psychometric tests on the mornings following the first (acute) day and seventh (sub-chronic) day. The tests were: Choice Reaction Time; Tracking; Critical Flicker Fusion Threshold; Memory Scanning; Continuous Attention Task; the Leeds Sleep Evaluation Questionnaire and a Visual Line Analogue Rating Scale. The results show that amitriptyline produced impairment of cognitive and psychomotor functions. Moclobemide, however, did not disrupt sleep or cause daytime sedation, and remained neutral in the assessment of behavioural toxicity.     

A double-blind, placebo- and flurazepam-controlled investigation of the residual psychomotor and cognitive effects of modified release zolpidem in young healthy volunteers

Short-acting hypnotic drugs, such as zolpidem, have minimal residual effects but may not provide optimal efficacy throughout the night for all insomnia patients. A modified-release formulation of zolpidem, zolpidem-MR, has been developed to overcome this limitation. This was a phase I, double-blind, 3-way crossover, placebo-controlled study to investigate the residual psychomotor and cognitive effects of a single oral dose of zolpidem-MR 12.5 mg in 18 healthy young adults. Flurazepam 30 mg was used as a positive control. No comparison with standard immediate-release zolpidem was made. Five neuropsychological tests and 2 subjective tests were performed 8 hours after dosing. The safety of zolpidem-MR was also investigated. Performance on the Critical Flicker Fusion Frequency test, Choice Reaction Time, Immediate and Delayed Word Recall, and the Compensatory Tracking Task was significantly impaired by flurazepam but not by zolpidem-MR (with the exception of the Compensatory Tracking Task) or placebo. No significant effects were observed on the Digit Symbol Substitution Test. The Leeds Sleep Evaluation Questionnaire showed that both drugs improved the ease of getting to sleep and perceived quality of sleep, whereas only flurazepam significantly impaired the ease of awakening. Neither drug scored significantly better than placebo on the Bond and Lader contentedness scale, but both induced a significant difference in calmness; only flurazepam significantly reduced alertness. The safety profile of zolpidem-MR was comparable to placebo. In conclusion, the study showed the good tolerance of zolpidem-MR in terms of residual neuropsychological effects as well as a beneficial effect on sleep quality in young healthy adults.     

The psychomotor and cognitive effects of a new antihistamine,mizolastine, compared to terfenadine,triprolidine and placebo in healthy volunteers

Eighteen healthy volunteers received mizolastine 5 mg, 15 mg or 45 mg, terfenadine 60 mg, triprolidine 10 mg or placebo in a 6-way crossover, double blind study. Following each dose, subjects performed a series of tests of cognitive function and psychomotor performance at 1, 3, 5, 8 and 24 hours post-dose. The test battery included critical flicker fusion, choice reaction time, tracking, Stroop and Sternberg memory tests and assessment of subjective sedation.Sedative effects and a concomitant reduction in psychomotor and cognitive function were observed following triprolidine, terfenadine and the highest dose of mizolastine, 45 mg, e.g. triprolidine reduced CFF threshold by 1.5 Hz and increased reaction time by 50 ms, impairments comparable to those caused by blood alcohol concentrations of 50 mg%, the legal limit in many countries. Mizolastine 5 mg did not differ significantly from placebo and at 15 mg differed only at one test point at one time.It may be concluded that mizolastine (5 mg and 15 mg) is free from disruptive effects on cognitive function and psychomotor performance, in contrast to terfenadine 60 mg, triprolidine 10 mg and mizolastine 45 mg.     

The effects of brofaromine alone and in conjunction with alcohol on cognitive function,psychomotor performance,mood and sleep in healthy volunteers

Brofaromine is a novel antidepressant that functions by the inhibition of the A form of monoamine oxidase (MAO). This inhibition is reversible, making brofaromine both pharmacologically and structurally different from most of the currently available MAO inhibitors. The drug has been shown to be clinically effective and to have significantly fewer problems than other MAO inhibitors in terms of hepatic toxicity and interaction with tyramine and coadministered tricyclic antidepressants. The present experiment was designed to assess the behavioural toxicity of the drug. Seventeen normal volunteers received brofaromine 50 mg or 75 mg, amitriptyline 50 mg or placebo with and without alcohol in a double blind eight-way crossover study. A psychometric test battery was administered at 3, 6 and 12 h post-dose. The results show that brofaromine had little or no effect on the measures employed, compared to placebo. The amitriptyline verum (with and without alcohol) however lowered critical flicker fusion threshold compared to placebo at all test points, increased reaction time, increased tracking error, and slowed memory scanning. It is concluded that, in volunteers, acute doses of brofaromine are free from disruptive effects on cognitive function and psychomotor performance, in contrast to both amitriptyline and alcohol which showed debilitating effects on most of the measures employed.     

The effects of cimetidine and ranitidine on psychomotor function in healthy volunteers

Summary

Single oral doses of cimetidine (400?mg), ranitidine (150?mg), promethazine (25?mg) or placebo were administered to 8 healthy volunteers in a double-blind study. Cimetidine and ranitidine did not cause any significant change in critical flicker frequency (c.f.f.), reaction time, pursuit rotor or the visual analogue scale scores for sedation. Promethazine significantly lowered c.f.f., prolonged reaction time and increased sedation when compared with placebo. It is concluded that in this study cimetidine and ranitidine had little, if any, effect on psychomotor function.     

Lack of effect of single and repeated doses of levocetirizine,a new antihistamine drug,on cognitive and psychomotor functions in healthy volunteers

Aims  Levocetirizine (R-cetirizine), is the active enantiomer of cetirizine, an antihistamine indicated in the treatment of allergic rhinitis and chronic idiopathic urticaria. The purpose of this trial was to analyse the effects of levocetirizine single and multiple doses on CNS using integrated measures of cognitive and psychometric performance.
Methods  A battery of psychometric tests was used: critical flicker fusion (CFF), choice reaction time (CRT), body sway (BS), learning memory test (LMT) and subjective assessments of alertness compared with placebo. Nineteen (19) healthy male volunteers received either levocetirizine 5 mg (therapeutic dose), diphenhydramine 50 mg or placebo once daily for 5 consecutive days (3-way cross-over). Diphenhydramine was used as a positive control. CFF tests were performed on days 1 and 5 at baseline and up to 24 h following drug intake. Subjects used the Bond-Lader visual analogue scales (VAS) to assess their mood and vigilance.
Results  In contrast to diphenhydramine, when compared with placebo, levocetirizine did not modify the CFF (primary endpoint), regardless of the dosing scheme (−1.62 Hz [−2.61, −0.64] and −0.81 Hz [−1.80, 0.19], respectively, 3 h after dosing on day 1). CRT was decreased with both levocetirizine and placebo up to 5 h after dosing on day 1 and up to 3 h after dosing on day 5. Body sway data were similar with levocetirizine and placebo but increased with diphenhydramine. LMT was similar in all three groups. No relevant difference between placebo and levocetirizine was recorded by the subjects on their assessment of alertness using the VAS, whilst decreased alertness was reported following diphenhydramine 50 mg.
Conclusions  This study showed that levocetirizine does not produce any deleterious effect on cognitive and psychometric functions compared with placebo in healthy male volunteers.     

ALDH2 genotype-associated differences in the acute effects of alcohol on P300, psychomotor performance, and subjective response in healthy young Korean men: a double-blind placebo-controlled crossover study

BACKGROUND: This study investigated the acute effects of alcohol on neurophysiological and psychomotor functions and the subjective response in healthy young Korean men according to the mitochondrial aldehyde dehydrogenase (ALDH2) genotype. METHOD: A total of 24 males, half with ALDH2*1/*1 (active form) and the rest with ALDH2*1/*2 (inactive form), were selected through genotyping. In a double-blind placebo-controlled crossover design, each subject consumed either a 0.5 g/kg dose of alcohol or a placebo on two separate occasions, 1 week apart. The blood alcohol concentrations (BACs), P300 of event-related potential, psychomotor performance, and perceived feelings were assessed. RESULTS: Although the BACs were similar between the two groups, the effects of alcohol on P300 were greater overall in subjects with ALDH2*1/*2 than in subjects with ALDH2*1/*1. Psychomotor performance was more impaired after alcohol ingestion in subjects with ALDH2*1/*2 than in subjects with ALDH2*1/*1. The subjective response after alcohol ingestion was more negative in subjects with ALDH2*1/*2, compared to subjects with ALDH2*1/*1. CONCLUSIONS: These results suggest that the ALDH2 polymorphism is an important factor in determining the effects of alcohol on various psychobehavioral functions.     

A double-blind,placebo- and positive-internal-controlled (alprazolam) investigation of the cognitive and psychomotor profile of pregabalin in healthy volunteers

Rationale Pregabalin potently and selectively binds to the alpha₂-delta subunit of voltage-dependent calcium channels, reducing calcium influx and modulating release of downstream excitatory neurotransmitters, such as glutamate. Pregabalin has demonstrated robust efficacy for several disease states, but its neuropharmacology is still being elucidated.Objective This study was conducted to evaluate the cognitive and psychomotor effects of oral pregabalin (150 mg t.i.d.) using alprazolam (1 mg t.i.d.) as a positive internal control and placebo.Methods Twenty-four healthy volunteers were randomised to a double-blind, three-way crossover study. Each period consisted of 3-day double-blind treatment followed by 1 day of single-blind placebo. Psychometrics included tests of Choice Reaction Time (CRT), CNS arousal (Critical Flicker Fusion, CFF), vigilance (Rapid Visual Information Processing, RVIP), serial memory scanning (Sternberg Short-Term Memory Scanning Test, STM), divided attention (Compensatory Tracking Task, CTT), Brake Reaction Time (BRT) in an on-the-road vehicle, and subjective Line Analogue Rating Scales (LARS) for sedation.Results Pregabalin showed no significant effects on the objective psychometrics—CRT, BRT, RVIP, STM—compared with placebo. Pregabalin produced a limited, significant decrement on CFF and CTT and a significant effect on the LARS. Pregabalin was associated with improvement relative to placebo in BRT. The positive control, alprazolam, produced significant impairment on all objective measures and significant impairment on the LARS, thus establishing the sensitivity of the test battery used in the study.Conclusions Pregabalin did not differ on most assessments from placebo, producing only minor, transient impairment on some objective cognitive and psychomotor measures, suggesting a relatively benign CNS side-effect profile.     

Evaluation of the cognitive, psychomotor and pharmacokinetic profiles of rupatadine, hydroxyzine and cetirizine, in combination with alcohol, in healthy volunteers

INTRODUCTION: The Central Nervous System (CNS) impairment induced by moderate alcohol (ALC) ingestion may be enhanced if other drugs are taken simultaneously. Rupatadine (RUP) is a new H(1)-antihistamine which also inhibits platelet activating factor (PAF) release in inflammatory reactions. OBJECTIVE: The main aim of the study was to assess the effects of ALC 0.8 g/Kg on RUP (10 mg and 20 mg) CNS effects. An evaluation of alcohol and RUP pharmacokinetics was also attained. METHODS: Eighteen healthy young volunteers of both sexes participated in a phase I, randomised, crossover, double-blind, placebo-controlled study. At 2-week intervals they received six treatments: (a) placebo (PLA), (b) ALC alone and ALC in combination with: (c) hydroxyzine 25 mg (HYD), (d) cetirizine 10 mg (CET), (e) RUP 10 mg or (f) RUP 20 mg. At baseline and several times thereafter, seven psychomotor performance tests (finger tapping, fine motoric skills, nystagmus, temporal estimation, critical-flicker-fusion frequency, 'd2' cancellation, simple reaction) and eleven subjective self-reports (drunkenness, sleepiness, alertness, clumsiness, anger, inattentiveness, efficiency, happiness, hostility, interest and extraversion) were carried out. Two-way (treatment, time) ANOVAs for repeated measures to each variable together with a multivariate non-parametric approach were applied. Plasma concentrations of alcohol, and of RUP and its metabolites, were quantified by validated immunofluorescence and LC/MS/MS methods, respectively. Plasma-time curves for all compounds were analysed by means of model-independent methods. RESULTS: The combination of alcohol with HYD, CET and RUP 20 mg produced more cognitive and psychomotor impairment as compared to alcohol alone, being the combination of alcohol and HYD the one which induced the greatest deterioration. The combination of alcohol and RUP 10 mg could not be differentiated from ALC alone. Subjective self-reports reflect effects on metacognition after the combination of alcohol with HYD and CET i.e. the increased objective impairment observed was not subjectively perceived by the subjects. No significant differences were obtained when comparing alcohol plasma concentrations assessed after the treatments evaluated. RUP showed a lineal kinetic relationship after 10 and 20 mg with a higher exposition to both metabolites assayed. CONCLUSIONS: Present results showed that single oral doses of rupatadine 10 mg in combination with alcohol do not produce more cognitive and psychomotor impairment than alcohol alone. Higher doses of rupatadine, in combination with alcohol, may induce cognitive and psychomotor deterioration as hydroxyzine and cetirizine at therapeutic doses.     

A double blind comparison of the effects of fluoxetine and amitriptyline on cognitive function in elderly depressed patients

Sixty-six elderly depressed patients received fluoxetine 20 mg (FLU) or amitriptyline 75 mg (AMI) for 42 days in a double blind parallel group study. Each week, subjects completed a test battery which is sensitive to the residual effects of psychoactive drugs. The results show that FLU and AMI were equally effective in relieving depression. However, the psychometric test battery showed that, compared to FLU, AMI, as expected, produced impairments in cognitive function and psychomotor performance. The relative impairment of cognitive and psychomotor skills following the tricyclic AMI and the lack of such activity after administration of the selective serotonin reuptake inhibition, FLU are important considerations when prescribing antidepressants, especially when the safety and well being of ambulant patients is essential.     

Comparative study of acute effects of single doses of fexofenadine, olopatadine, d-chlorpheniramine and placebo on psychomotor function in healthy volunteers

Since most classical (first-generation) antihistamines have undesirable sedative effects on the central nervous system (CNS), newer (second-generation) antihistamines have been developed to relieve the sedative effects and to improve the patient's quality of life. However, the psychomotor profiles of second-generation antihistamines are not fully elucidated. In this randomized, double-blind, crossover study, the acute effects of single doses of second-generation antihistamines, fexofenadine (120 mg) and olopatadine (10 mg), on cognitive and psychomotor performance were investigated in comparison with those of placebo and d-chlorpheniramine (4 mg), a first-generation antihistamine, using objective and subjective assessments, in 11 healthy Japanese volunteers. In a battery of psychomotor tests, d-chlorpheniramine impaired tracking ability in the compensatory tracking task and caused a reduction in behavioural activity as continuously measured by wrist actigraphy. Olopatadine, like d-chlorpheniramine, reduced the behavioural activity, while fexofenadine had no effect in any of the tests. No significant changes in the subjects' self-ratings of drowsiness were found with the three antihistamines. These results suggest that d-chlorpheniramine and olopatadine, but not fexofenadine, produce sedative effects on psychomotor performance, and that the CNS profile of fexofenadine is different from that of olopatadine.     

Electroencephalographic and psychomotor effects of chlorpromazine and risperidone relative to placebo in normal healthy volunteers

AIMS: To investigate the effects of single oral doses of chlorpromazine (50 mg) and risperidone (2 mg) relative to placebo on topographical electroencephalometry (CATEEMTM ) and psychomotor tests in 12 healthy male volunteers. METHODS: A double-blind, placebo-controlled, three-way crossover design using a double dummy blinding technique was utilized. Chlorpromazine was selected as representative of the 'typical' neuroleptics, being also highly sedative. Risperidone has been suggested as representative of the newer 'atypical' neuroleptics and is claimed to be only minimally sedative. Volunteers were dosed on 3 separate days with a minimum of 7 days interval between trial days. On each trial day volunteers were dosed twice. Dose 1 consisting of either chlorpromazine 50 mg or placebo to chlorpromazine, and dose 2 either risperidone 2 mg or placebo to risperidone. The volunteers were randomized so that each received either chlorpromazine or risperidone (or neither), but not both on an individual trial day. A 17 electrode quantitative topographical electroencephalograph (EEG) recording was taken for each volunteer before and after each dosing period. Seven psychomotor function tests were used to determine the effects of each treatment on psychomotor performance. RESULTS: The data confirm the cited reports of sedation following single oral doses of chlorpromazine 50 mg. However, 7 of the 12 volunteers dosed with risperidone 2 mg also reported drowsiness/lethargy which was of greater severity and duration than 5 of the 12 volunteers who reported somnolence following dosing with chlorpromazine 50 mg. Objective assessment of psychomotor impairment using a short battery of psychomotor function tests mirrored the subjective reports of somnolence in that the impairment in volunteers dosed with risperidone 2 mg was greater in extent and magnitude than in volunteers dosed with chlorpromazine 50 mg. With respect to the cortical quantitative electroencephalogram, both chlorpromazine (50 mg) and risperidone (2 mg) increased power (4.75-6.75 Hz) in keeping with cited effects of other neuroleptics on the quantitative EEG. In addition, there was a statistically significant increase (P<0.05) in alpha1 (7.0-9.5 Hz) and beta1 (12.75-18.5 Hz) wavebands in volunteers dosed with risperidone 2 mg. Furthermore, based on estimates of variability, we propose that a 3 min eyes open and 3 min eyes closed quantitative EEG recording is sufficient to maintain adequate power for this technique, whilst allowing its application to early volunteer trials of novel neuroleptic agents. CONCLUSIONS: This study demonstrates that quantitative EEG can be utilized in the profiling of neuroleptic agents, and could be readily applied to the early profiling of novel neuroleptics in limited numbers of volunteers, early in drug development. The chosen battery of psychomotor tests has clearly demonstrable sensitivity to the quantification of the subjective reports of somnolence secondary to both chlorpromazine and risperidone.     

The cognitive and psychomotor effects of opioid analgesics

Twelve subjects (8 male) took part in a randomised double blind four way crossover design study comparing four treatments: (i) morphine sulphate 10 mg, (ii) morphine sulphate 15 mg, (iii) lorazepam 1 mg (positive control) and (iv) placebo. Cognitive function was assessed using choice reaction time, number vigilance, memory scanning, immediate and delayed word recall, word recognition, picture recognition, critical flicker fusion threshold (CFFT) and subjective measures of alertness, calmness and contentment. Lorazepam produced a marked impairment in the tests of attention and memory. CFFT was reduced from 1–4 h but this only reached significance at 4 hours. The subjective measures suggested impaired alertness but this did not reach significance. The effects of morphine were less dramatic; both doses of morphine produced significant impairment at 1 hour on tests of secondary memory retrieval (delayed word recall and picture recognition sensitivity). CFFT was reduced for the whole observation period (6 h) achieving statistical significance at 4 hours. Morphine 15 mg produced a significant improvement in accuracy on the choice reaction time test at the 2, 4 and 6 h assessments. These results show minimal impairment of cognitive and psychomotor function after single oral doses of morphine and with possible improvement in one test. Further studies are required to examine the effect of repeated doses.     

The influence of levodopa on gastric emptying in healthy elderly volunteers

Summary Paracetamol absorption and ⁹⁹Tc-DTPA measurements have been used to determine the influence of levodopa on gastric emptying in 8 healthy elderly volunteers.In the absence of levodopa 7 subjects showed a rapid gastric emptying pattern by gamma-camera and a single major peak in the plasma concentration-time curve of paracetamol. One subject showed two rapid phases of gastric emptying separated by a period of negligible emptying and had 2 separate peaks in the paracetamol plasma concentration-time curve.In the presence of levodopa, the gamma-camera data for 6 subjects showed a pattern of gastric emptying consisting of 2 rapid phases separated by a plateau. In each case secondary peaks in the plasma concentration-time curve of paracetamol occurred about 30 min after the end of the plateau. The time to 90% emptying on the gamma scan was increased significantly from 40 min to 65 min in the presence of levodopa.Comparison of the present data with those reported previously indicates that levodopa affects gastric emptying in the both elderly and young volunteers to a similar extent.     

Pharmacodynamics of milnacipran in young and elderly volunteers

AIMS: To investigate the pharmacodynamics of milnacipran in healthy young and elderly volunteers. METHODS: Randomized double-blind crossover designs were employed and a standardized psychometric battery was administered pre and post dose for both studies. In the first study 10 healthy young volunteers received milnacipran 12.5 mg, 25 mg, 50 mg, 100 mg as a single dose or matched placebo. The test battery was administered at baseline and at 1, 2, 4 and 6 h post dose. The second study compared the effects of milnacipran 75 mg (50 mg+25 mg) per day, amitriptyline 50 mg (25 mg+25 mg) per day and placebo for 3 days' dosing in healthy volunteers aged over 65 years. The test battery was administered at baseline and at 2, 10 and 24 h post dose. The psychometric battery included critical flicker fusion (CFF), choice reaction time (CRT), compensatory tracking (CTT) and tests of short-term memory (STM), subjective sedation (LARS) and subjective sleep (LSEQ). RESULTS: Milnacipran produced no significant dose related effects in the young volunteers. For the elderly, milnacipran significantly (P<0.05) raised CFF scores compared with placebo but had no significant effects on any of the other measures used. Amitriptyline, in contrast, significantly (P<0. 05) lowered CFF threshold, lengthened CRT and increased error on the CTT. On the subjective variables, LARS and LSEQ, amitriptyline increased ratings both of sedation and of difficulty in waking from sleep. CONCLUSIONS: The results showed that milnacipran at single doses of up to 100 mg in healthy young volunteers is free from disruptive effects on cognitive function and psychomotor performance. In addition, milnacipran 75 mg (50+25 mg) appears to be free of negative effects on cognitive function in elderly volunteers, where it seemingly improves performance on CFF. In contrast, the tricyclic antidepressant amitriptyline, used here as a positive internal control, significantly impaired performance in the elderly on the majority of psychometric measures used in this study. This finding not only validated the sensitivity of this current test battery but also indicates the potential behavioural toxicity of amitriptyline in clinical use in the elderly.