A double-blind comparison of the pharmacodynamic effects of single doses of lofepramine,amitryptyline and placebo in elderly subjects

Summary In a double-blind five-way cross-over study, six drug free healthy elderly subjects received single oral doses of lofepramine (70 mg, 105 mg and 140 mg), amitriptyline (50 mg) and matched placebo tablets.A dose related increase in plasma drug levels and pharmacological effects of lofepramine was observed. Lofepramine (140 mg) improved psychomotor performance (choice reaction time and letter cancellation), but no such change was seen with lower dose regimes or placebo. No significant differences between lofepramine and placebo were observed in other parameters measured.Amitriptyline, as expected, reduced salivary volume, produced drowsiness and impaired psychomotor performance. These changes correlated with plasma amitriptyline levels. The incidence of subjective side-effects with amitryptyline was also higher than that of lofepramine or placebo.In the dosage used, lofepramine exhibited no deleterious effect on the peripheral cholinergic system or psychomotor performance. This drug therefore is likely to be a relatively safe antidepressant for the elderly, but further investigations during long-term medication are required to verify these observations.     

A comparison of the effect of lofepramine,maprotiline and placebo on information processing in healthy volunteers

Single oral doses of lofepramine (140 mg), maprotiline (100 mg), and placebo were administered in a randomized three-way crossover design with 1 week wash-out between administrations to 12 healthy male volunteers. Before, and 1, and 3 h post-administration a battery of performance tests was administered which included a digit-matching paradigm and a reaction test separating recognition and motor time. In contrast to maprotiline, lofepramine did not impair speed and accuracy of cognitive performance.     

Pharmacokinetics of lofepramine and amitriptyline in elderly healthy subjects

Pharmacokinetics of 3 doses (70 mg, 105 mg and 140 mg) of lofepramine were compared with amitriptyline (50 mg) in 6 healthy drug free elderly subjects aged between 65 and 72 years. Pharmacokinetics of lofepramine in the elderly appear to be similar to young adults as published before. Peak plasma lofepramine and amitriptyline concentrations were achieved at about 1 h and 3 h of dosing respectively. Elimination half-life of lofepramine was 2.5 h and that of amitriptyline was 31 h. A 24-fold inter-individual variation in peak plasma lofepramine concentrations was observed, but amitriptyline levels in plasma showed less variation. Pharmacokinetic parameters of amitriptyline were comparable to other published studies involving elderly people. Compared to placebo and lofepramine, amitriptyline produced drowsiness and dry mouth, reduced salivary volume and increased movement reaction time. These effects correlated with the plasma amitriptyline levels.     

A comparison of the pharmacodynamic profiles of nomifensine and amitriptyline in normal subjects.

1 Six healthy male volunteers participated in a double-blind placebo crossover comparison of the pharmacodynamic profiles of single oral doses of 75 mg nomifensine and 50 mg amitriptyline. 2 Nomifensine treatment did not influence salivary flow and did not significantly affect psychomotor performance (critical flicker fusion, pursuit rotor and reaction time): in addition nomifensine had no significant effect on subjective measurements of sedation and concentration. 3 By contrast, amitriptyline treatment significantly reduced salivary flow and was associated with significant sedation and reduced concentration: significant changes in psychomotor performance were also noted. 4 Plasma concentrations of amitriptyline and nomifensine were measured at 2 h. The respective median concentration values were 55.0 ng/ml and 52.0 ng/ml. 5 Ex vivo platelet amine uptake of dopamine (DA) and 5-hydroxytryptamine (5HT) was measured 2 h after each treatment. Both nomifensine and amitriptyline treatment significantly inhibited DA uptake to a similar extent. Amitriptyline treatment additionally inhibited 5-HT uptake.     

Effects of lofepramine on human sleep: a pilot study

The influence on objective and subjective sleep variables and tolerance of lofepramine (140 mg) given as a single night time dose was compared with placebo in a double-blind cross-over study. Four healthy male volunteers on the same 2 nights of 2 consecutive weeks took either lofepramine or placebo in a randomized order. On 2 successive mornings of the third week all subjects took 140 mg lofepramine after breakfast. The main variables were electrophysiological measures of all night sleep. Supplementary, scores on a sleep questionnaire after each night, and scores on a side-effect questionnaire every morning and evening of the experiment were obtained. Lofepramine reduced paradoxical sleep and increased REM latency. There was a tendency for more intra-sleep restlessness but no relevant changes in sleep continuity variables. In these subjects lofepramine did not change subjective judgement of sleep quality and of feeling refreshed after sleep. No side-effects were reported.     

Interaction of alcohol with maprotiline or nomifensine: Echocardiographic and psychometric effects

Summary Eight healthy volunteers received low doses of maprotiline and nomifensine up to 50 mg b. d. for 15 days in a double-blind, cross-over, placebo controlled study, during which echocardiography and psychomotor testing were carried out before and after the intake of alcohol 1 g/kg.Maprotiline increased heart rate and cardiac output and reduced peripheral resistance compared to placebo and nomifensine. Nomifensine alone was associated with a slight decrease in heart rate. Alcohol alone caused a significant increase in diastolic blood pressure, but did not otherwise modify the cardiovascular measures. The antidepressants did not augment the effects of alcohol.Antidepressants alone had no effect on psychomotor skills, but alcohol always impaired performance. No additional effects of alcohol were produced by the antidepressants.It appears that practically important peripheral or central consequences are unlikely to follow drinking a moderate amount of alcohol during regular therapy with low therapeutic doses of catecholamine reuptake inhibiting antidepressants. Experimental studies of the interaction of antidepressants and alcohol in patients with chronic heart disease seem to be justified.     

Experimental investigation of psychophysiological effect of a new antidepressant (lofepramine) as compared to imipramine and placebo (author's transl)

Using 24 non-selected healthy male students the effects of imipramine (single dose of 100 mg orally) and 4'-chloro-2-[3-(10,11-dihydro-5H-dibenz[b,f]azepin-5-yl)-propyl]-methylamino]-acetophenone-hydrochloride (lofepramine, Gamonil) (single dose of 140 mg orally) in comparison to placebo (doubleblind) on subjective, physiological and performance variables were examined. All subjects (Ss) received the three drugs in a completely counterbalanced sequence. On the basis of their scores on the Depression Scale of the Freiburger Personality Inventory (FPI, Fahrenberg) Ss were divided into two groups of 12 Ss each, "high depression" and "low depression" group. Two-way analyses of variance were computed. Imipramine and Lofepramine elevate scores in the mood scale, but only for the "high depression" group. For the Ss scoring lower in depression no such effect can be demonstrated. The physiological effects are similar. Reported side effects are less for lofepramine than for imipramine.     

The lack of CNS effects of nizatidine,with and without alcohol,on psychomotor ability and cognitive function

The aim of the study was to measure the effects of nizatidine (150 mg, 300 mg, and 600 mg), with and without alcohol (0.5 g/kg body weight) on a battery of test of psychomotor functioning, short-term memory and subjective rating of sedation. A placebo and positive internal control (lorazepam 1 mg) crossover design was used, with each subject acting as her own control. The study population consisted of 10 healthy female volunteers with an age range of 20–50 years. The results show that nitatidine, at the range of doses studied, has no demonstrable effect on any of the measures of CNS activity and psychomotor performance. This lack of CNS effect was demonstrated in a study where the verum showed a consistent impairment of CNS activity. Furthermore there was no potentiation of the effects of alcohol by any of the doses of nizatidine used.     

Nomifensine,clobazam and HOE 8476: Effects on aspects of psychomotor performance and cognitive ability

Summary The effects of a combination of nomifensine and clobazam (HOE 8476) were compared, on a variety of psychometric measures, with those of its separate monosubstances in a placebo controlled double-blind study with twelve normal volunteers. Assessments comprised a range of psychomotor performance tests, measures of cognitive processing ability and visual analogue rating scales — previously shown to be sensitive to the effects of psychotropic drugs. Subjects acted as their own control and were tested in the morning and afternoon following subchronic pre-dosing with each of the four treatments. When compared with placebo, nomifensine showed no significant change on any of the performance measures. HOE 8476 produced no significant changes in performance but significantly reduced self-rated anxiety. Clobazam significantly improved subjective ratings of the ease of getting to sleep and impaired choice reaction time and concept identification performance in the morning. No significant changes in the test measures were found in the afternoon following any treatment. The findings were in broad agreement with those of previous studies and demonstrated that clobazam and nomifensine, both alone and in combination, tended not to impair performance on a wide range of psychological test assessments.     

The effects of dimenhydrinate, cinnarizine and transdermal scopolamine on performance

We assessed the influence of dimenhydrinate, cinnarizine and transdermal scopolamine on the ability to perform simulated naval crew tasks. The effect of single doses of dimenhydrinate, 100 mg, cinnarizine, 50 mg, and one transdermal scopolamine patch on psychomotor performance was evaluated using a double-blind, placebo-controlled, randomized, crossover design in three separate studies. A total of 60 young naval crew (20 for dimenhydrinate, 15 for cinnarizine and 25 for transdermal scopolamine) underwent a battery of computerized and paper and pencil performance tests, and filled out a questionnaire on side-effects and well-being self-assessment. Dimenhydrinate significantly impaired decision reaction time and auditory digit span. Most of the subjects who took dimenhydrinate also reported a subjective decrease in well-being and general performance abilities. Cinnarizine and transdermal scopolamine did not affect performance abilities. Cinnarizine was free of significant side-effects. Dry mouth was the only significant side-effect of transdermal scopolamine. These findings could be explained by the well-known sedative properties of dimenhydrinate and not by a specific effect on any particular cognitive or motor function. Our results suggest that dimenhydrinate, 100 mg, adversely affects psychomotor function, whereas single doses of cinnarizine, 50 mg, and transdermal scopolamine appear to be free of side-effects on performance and seem to be a preferable anti-seasickness drug for use by a naval crew.     

The effect of low dose lofepramine in depressed elderly patients in general medical wards.

A double-blind randomised controlled trial of the effect of low dose lofepramine (70 mg once daily) against placebo was carried out on depressed elderly inpatients on general medical wards for the elderly, comparing measures of depression and side-effects between the randomised groups. Patients were identified for the study using the Geriatric Depression Scale (GDS) and the Brief Assessment Schedule Depression Cards (BASDEC). Sixty-three subjects were randomised: 46 patients completed the entire trial of 28 days treatment. BASDEC and GDS were administered on day 8 post-admission, and depressed patients were randomised double-blind to either low dose lofepramine (70 mg daily) (n = 23) or placebo (n = 23). Assessment of changes in depressive states were made using the Montgomery Asberg Depression Rating Scale (MADRS) on days 8, 18 and 36 post-admission. Both groups improved by a similar amount during the trial. Lofepramine tended to be more effective than placebo in those patients who were more depressed (GDS > or = 18). On the other hand, subjects who were less depressed (i.e. GDS < 18) improved more on placebo than lofepramine. Low dose lofepramine may prove useful in moderately or severely depressed patients treated for only 4 weeks. However, low dose lofepramine is not indicated for mild (GDS 15-18) depression.     

Comparative effects of conventional B-blockers and nebivolol on psychomotor performances in healthy volunteers: a preliminary report

The present study was under taken to assess the comparative effects of nebivolol with propranolol and atenolol on psychomotor performances. Thirty healthy volunteers were randomized into three groups with n=10 in each group. Each subject received single dose of one of the three medications (nebivolol 5 mg, atenolol 50 mg and propranolol 40 mg) in morning (9:00 AM). Just before administering the drug, the pre-drug scores were taken, followed by post drug score obtained for consecutive six hours. Psychomotor assessment was carried out by three tests Simple Reaction Timer (SRT), Critical Flicker Fusion Frequent Threshold (CFFT) and Digit Cancellation Test (DCT). The results of present study indicate that single doses of atenolol and propranolol produced significant impairment of psychomotor performance. Nebivolol also impaired psychomotor performance tests in the similar fashion to atenolol and propranolol. Hence, the findings of the present study correlate with the lipophilic nature of the nebivolol.     

Effects of terfenadine and diphenhydramine alone or in combination with diazepam or alcohol on psychomotor performance and subjective feelings

Summary The effects of single oral doses of terfenadine, diphenhydramine and placebo, alone or in combination with diazepam or alcohol, on psychomotor performance and subjective feelings were evaluated in a double-blind, crossover study in 20 normal male volunteers. Terfenadine 60, 120 and 240 mg had no effect on psychomotor skills and subjective feelings, whereas diphenhydramine 100 mg slightly impaired certain features of psychomotor performance and severely worsened subjective feelings. Terfenadine 120 mg did not influence the adverse effects of oral diazepam 10 mg or of alcohol 0.75 g/kg on psychomotor performance and subjective feelings. In contrast, diphenhydramine 100 mg significantly enhanced these effects of diazepam and alcohol.     

The effects of single doses of CL 284,846, lorazepam,and placebo on psychomotor and memory function in normal male volunteers

Summary The effects of single doses of CL284,846 (20 mg), lorazepam (2 mg) and placebo on psychomotor performance, memory function and subjective feelings were assessed in 12 normal, healthy male volunteers. Each subject received each treatment in balanced order and a minimum of 6 days was left between treatments.The subjects performance on a comprehensive battery of tests of psychomotor performance, memory function and subjective ratings was assessed pre-treatment and at 1, 3 and 5 h post-treatment.In general, the effects of CL284,846 on memory were similar to those of lorazepam at 1 h post-treatment but, recovery was rapid with CL284,846. Impairments induced by lorazepam persisted throughout the post-drug testing sessions.This pattern of effects was repeated across most of the variables tested. However, at 1 h, CL284,846 produced less marked psychomotor impairment than lorazepam.The results of this study suggest that CL284,846 is a safe, rapid acting and effective sedative with some clear advantages over lorazepam with respect to unwanted cognitive and psychomotor impairments.     

Acute pharmacological effects of temazepam,diphenhydramine, and valerian in healthy elderly subjects

Elderly insomniacs are often treated pharmacologically with benzodiazepines, antihistamines, or natural products. A double-blind, randomized, crossover, placebo-controlled study was performed to assess the comparative pharmacodynamics of single doses of temazepam (15 and 30 mg), diphenhydramine (50 and 75 mg), and valerian (400 and 800 mg) in 14 healthy elderly volunteers (mean age, 71.6 years; range, 65-89). Assessments were made at 0, 0.5, 1, 2, 3, 4, 6, and 8 hours postdosing with use of validated measures of subjective sedation and mood (visual analogue scales, Tufts University Benzodiazepine scale) and psychomotor performance (manual tracking and digit symbol substitution tests). Temazepam had dose-dependent effects on sedation and psychomotor ability with a distinct time course. Temazepam 30 mg had the most detrimental effect on psychomotor ability (p < 0.001 compared with all other treatments). Temazepam 30 mg and both doses of diphenhydramine elicited significantly greater sedation than placebo (p < 0.05, all), and temazepam had the greatest effect. There was no difference in sedation scores between 50 and 75 mg diphenhydramine. Sedative effects were slightly lesser with 15 mg temazepam and were not significant in comparison with placebo. Psychomotor impairment was evident after administration of 75 mg diphenhydramine in comparison with placebo on the manual tracking test (p < 0.05); this was less than the impairment with 30 mg temazepam (p < 0.001) but similar to that with 15 mg temazepam (NS). No psychomotor impairment was detected with 50 mg diphenhydramine. Valerian was not different from placebo on any measure of psychomotor performance or sedation.     

Influence on the electrocardiogram of rats by antidepressants

The influence of lofepramine on the heart has been studied in anaesthetized rats. Lofepramine and other antidepressants were infused i.v. during 4 h at a rate of 0.5 mg/kg/min for lofepramine (equimolar concentrations for the other antidepressants). ECG and survival time were recorded. It was shown that lofepramine in contrast to the other antidepressants tested did not influence the PQ- and QRS-times at all. The other antidepressants tested increased the PQ-time 20-170% and the QRS-time 40-130%. Only the rats in the lofepramine group survived the whole experiment. The occurrence of multiple arrhythmias was low in this study and the difference between the groups was not striking. In further 13 rats the plasma level of desipramine, the main metabolite of lofepramine, after 200 min of lofepramine and 100-135 min of desipramine infusion was measured. The levels of desipramine at that time were found approximately comparable after infusion of the two different substances.     

The effects of acute doses of dothiepin (25, 50, and 75 mg) versus placebo on psychomotor performance and cognitive function

Sixteen healthy volunteers received dothiepin 25 mg, 50 mg, 75 mg and placebo in a double-blind crossover study. Each subject received the four treatments once, with a 6-day washout period between test days. On each occasion psychomotor performance and cognitive function were measured 30 min before dosing and 1, 2, 4, 6 and 8 h after drug administration. The test battery comprised: Critical Flicker Fusion, Choice Reaction Time, Continuous Tracking and Short Term Memory. Subjective ratings of sedation were measured using Line Analogue Rating Scales. Dothiepin at the subtherapeutic dose of 75 mg was shown to produce statistically significant impairment (p<0·05) on several of the variables investigated. These included CFF at the 2- and 4-h test points, TRT at the 2-h test point and LARS at the 2- and 4-h test points. Lower doses also produced impairment of cognitive function and psychomotor performance as measured by the present test battery. © 1997 John Wiley & Sons, Ltd.     

Psychomotor, Cognitive, extrapyramidal, and affective functions of healthy volunteers during treatment with an atypical (amisulpride) and a classic (haloperidol) antipsychotic.

The primary objective of this study was to compare the objective and subjective effects of amisulpride with those of a classic antipsychotic, haloperidol, when both were given to healthy volunteers in representative therapeutic doses over 5 days. The secondary objective was to compare the effects of relatively low and high doses of amisulpride to confirm the suspected duality of its pharmacologic activity. Twenty-one subjects participated in the four-way, randomized, double-blind, crossover study with repeated daily doses of amisulpride 50 mg, amisulpride 400 mg, haloperidol 4 mg, and placebo. Subjects were institutionalized during treatment periods and were under 24-hour medical supervision. They underwent a series of psychomotor and cognitive tests 1 hour before and 3 and 6 hours after dosing on days 1 and 5. Their extrapyramidal disturbances and drug-related feelings were assessed at the end of each replication. Psychiatric interviews and ratings of depression, subjective well-being, and negative symptoms occurred on day 4. Amisulpride 50 mg had no significant effect on any parameter. Amisulpride 400 mg had several adverse effects on psychomotor and, although less severe, on cognitive performance on the fifth day only. Amisulpride 400 mg produced no significant extrapyramidal disturbances in the group as a whole, although it may have in some individual subjects. Also, it produced no signs of mental disturbances on clinical rating scales or during a structured psychiatric interview. Haloperidol ubiquitously impaired psychomotor and cognitive performance in a similar fashion after the first and the final doses. It produced extrapyramidal disturbances in nearly every subject, the most common being akathisia and the most severe, in the case of one individual, being acute dystonia. Unlike amisulpride, haloperidol produced a number of mental disturbances, the most noteworthy being negative symptoms. Amisulpride seems to be a well-tolerated drug. Its side effects should be much less troublesome to patients using the drug on a long-term basis than those of classic antipsychotics, like haloperidol.