Effects of 5 weeks of administration of fluoxetine and dothiepin in normal volunteers on sleep,daytime sedation,psychomotor performance and mood

This was a placebo-controlled, double-blind randomized crossover study of long-term (5 weeks) administration of fluoxetine (20 mg/day) and dothiepin (75 mg/day for 1 week followed by 150 mg/day for 4 weeks) in 12 healthy male volunteers. Subjects were studied on day 10 and day 36 of treatment, with tests of nocturnal sleep, driving performance, continuous electroencephalogram (EEG), sleep during scheduled naps, computerized visual attention tasks, saccadic eye movement measurement and visual analogue ratings of mood. Both drugs had a marked suppressive effect on nocturnal rapid eye movement (REM) sleep; these effects were less at 36 days than at 10 days, and fluoxetine decreased and dothiepin increased REM in daytime naps. Sleep fragmentation after fluoxetine is similar to that reported in the literature. We found no sleep-promoting effects of dothiepin, in contrast to our previous single-dose study, and no subjective sleep effects of either drug. Subjects were less sleepy after both antidepressants than placebo at 5 weeks measured by sleep latencies and EEG. Saccadic eye movement measures were significantly faster after 5 weeks of fluoxetine than after 5 weeks of placebo. Reaction times to a peripheral stimulus during computerized tracking task were shorter after 10 days of dothiepin compared with placebo. Driving performance, visual attention and mood ratings showed no treatment effects. Subjective health reports during each 5 weeks of treatment were similar in number for the two drugs but showed a different profile of side-effects.     

Citalopram Compared to Dothiepin and Placebo: Effects on Cognitive Function and Psychomotor Performance

Three doses of citalopram (10, 20 and 40 mg), and placebo were administered to healthy volunteers for periods of 8 days each. Dothiepin 75 mg was given as an acute dose on days 1 and 8 only, with placebo dothiepin on days 2–7. Subjects were tested on days 1 and 8 of the dosing periods on a battery of psychometric tests. The results showed that citalopram at all doses had no detrimental effects on psychomotor performance. The effect of citalopram on critical flicker fusion (CFF) was to raise thresholds. This indicates an improvement in CNS function, i.e. an elevation of cognitive processing ability, with no evidence of an arousing or alerting effect. The effects were apparent after both acute and sub-chronic dosing. These data are in contrast to those collected for dothiepin, which showed significant impairment of cognitive and psychomotor function on most of the measures employed. The most frequent adverse events reported for citalopram were drowsiness, nausea and headache, with the nausea appearing to be dose dependent. The main adverse events reported for dothiepin were drowsiness, sleepiness and dizziness. The rates of adverse events for all active treatments were not statistically significantly different to placebo. It is concluded that citalopram is relatively free from behavioural toxicity and so represents a significant improvement over the older antidepressant agents such as dothiepin. © 1997 by John Wiley & Sons, Ltd.     

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.     

A double-blind, randomized, controlled trial of fluoxetine plus quetiapine or clomipramine versus fluoxetine plus placebo for obsessive-compulsive disorder

Obsessive-compulsive disorder patients who do not improve sufficiently after treatment with a selective serotonin reuptake inhibitor might improve further if other drugs were added to the treatment regimen. The authors present a double-blind, placebo-controlled trial comparing the efficacy of adding quetiapine or clomipramine to a treatment regimen consisting of fluoxetine. Between May 2007 and March 2010, a total of 54 patients with a primary diagnosis of obsessive-compulsive disorder, as defined by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, and a current Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) score of at least 16, the score having dropped by less than 35% after fluoxetine monotherapy, were allocated to 1 of 3 arms (n = 18 per arm): quetiapine + fluoxetine (≤200 and ≤40 mg/d, respectively), clomipramine + fluoxetine (≤75 and ≤40 mg/d, respectively), or placebo + fluoxetine (≤80 mg/d of fluoxetine). Follow-up was 12 weeks. The Y-BOCS scores were the main outcome measure. No severe adverse events occurred during the trial, and 40 patients (74%) completed the 12-week protocol. The Y-BOCS scores (mean [SD]) were significantly better in the placebo + fluoxetine and clomipramine + fluoxetine groups than in the quetiapine + fluoxetine group (final: 18 [7] and 18 [7], respectively, vs 25 [6], P < 0.001) (reduction from baseline: -6.7 [confidence interval {CI}, -9.6 to -3.8; and -6.5 [CI, -9.0 to -3.9], respectively, vs -0.1 [CI, -2.9 to 2.7], P < 0.001; number needed to treat = 2.4). The clomipramine-fluoxetine combination is a safe and effective treatment for fluoxetine nonresponders, especially those who cannot tolerate high doses of fluoxetine. However, the period of monotherapy with the maximum dose of fluoxetine should be extended before a combination treatment strategy is applied.     

Fluoxetine pharmacokinetics and effect on CYP2C19 in young and elderly volunteers

The objective of this study was to assess in both young and elderly volunteers the pharmacokinetics of fluoxetine and norfluoxetine and effects on cytochrome P450 (CYP) 2C19. Male volunteers aged 18 to 40 years (N = 14) or older than 65 years (N = 16) received fluoxetine 20 mg/day for 6 weeks and fluoxetine 40 mg/day for an additional 6 weeks. Blood was drawn over a 24-hour period after the initial dose and after 6 weeks and 12 weeks to determine AUC0-24, Cmax, and tmax; weekly to evaluate predose levels (C0); and over a 3-week period after discontinuation to evaluate washout (t1/2). Mephenytoin was used to assess CYP2C19 activity before and after 6 weeks and 12 weeks of fluoxetine. Fluoxetine AUC0-24, C0, and Cmax did not differ in young and elderly subjects. The norfluoxetine C0 was 22% lower in elderly subjects (p < .05), with comparable decreases in AUC0-24 and Cmax. In the elderly volunteers, the t1/2 for fluoxetine was 25% longer (5.0 vs. 4.0 days) and for norfluoxetine was 33% longer (20 vs. 15 days), although variability and sample size precluded statistical significance. Fluoxetine dosing inhibited CYP2C19 activity in both age groups, increasing the (S)- to (R)-mephenytoin ratio 3- to 4-fold (p < .01). The half-lives of fluoxetine and norfluoxetine at 40 mg/day were longer than commonly reported in the literature and may be longer in elderly subjects. Fluoxetine substantially inhibited the metabolism of the CYP2C19 substrate (S)-mephenytoin.     

Ethanol interactions with serotonin uptake selective and non-selective antidepressants: Fluoxetine and amitriptyline

Fluoxetine, unlike amitriptyline, selectively blocks serotonin uptake. The interactions of steady state levels of fluoxetine with ethanol and of amitriptyline with ethanol were measured in a double-blind, chronic dose, randomized study. Sixteen healthy men, ages 21 to 28 years, were tested with placebo and ethanol (dosed to maintain blood ethanol concentration of 17–22 mM) and placebo and juice on two separate days. For 14 nights, 8 subjects took fluoxetine 40 mg, 8 took amitriptyline 50 mg, and all were re-tested with ethanol and juice as before. Ethanol had no effect on inhibition of serotonin uptake or on pharmacokinetics of fluoxetine or amitriptyline. The deleterious effects of ethanol on memory, manual tracking, body sway, intoxication and sedation (p<0·05) were not modified by either fluoxetine or amitriptyline. This study design, which is sensitive enough to detect ethanol effects, suggests that ethanol dose not interact importantly with clinically relevant doses of fluoxetine or low doses of amitriptyline administered chronically.     

Augmentation of fluoxetine's antidepressant action by pindolol: analysis of clinical, pharmacokinetic, and methodologic factors

In a controlled trial, the beta-adrenoceptor/5-hydroxytryptamine-1A (5-HT1A) receptor antagonist pindolol accelerated and enhanced the antidepressant effect of fluoxetine. The median times to sustained response (> or = 50% reduction of baseline severity maintained until endpoint) were 19 days for fluoxetine plus pindolol (N = 55) and 29 days for fluoxetine plus placebo (N = 56) (p = 0.01). The response rate at endpoint was 16% greater in patients treated with the combination. The plasma concentration of pindolol remained stable between 3 days (first blood sampling) and 6 weeks. Mean values were approximately 26 nM, a concentration higher than the Ki of (-)pindolol for human 5-HT1A autoreceptors (11 nM). Plasma fluoxetine and norfluoxetine concentrations increased steadily until the fourth week of treatment. Fluoxetine concentrations were lower in patients receiving the combination (p = 0.043), but there was no significant relationship to the clinical response in either group. A reanalysis of the data using a survival analysis revealed that significant differences in the time to sustained response between both groups would have also been detected (1) in a 2-week trial, (2) without a placebo lead-in phase, and (3) with less frequent visits. However, the use of "response" instead of "sustained response" as measure of clinically relevant change would have greatly diminished the difference between treatment arms (p = 0.08 instead of p = 0.01). This emphasizes the need of using stringent outcome criteria in antidepressant drug trials. A comparison of the data of all sustained responders (N = 27) in the fluoxetine-plus-placebo group with the first 27 responders in the fluoxetine-plus-pindolol group (of a total of 38) revealed a highly significant difference in the time to sustained response (18 and 10 days, respectively; p = 0.0002). This indicates that the faster response in the fluoxetine-plus-pindolol group is not a result of the greater proportion of responders.     

Fluoxetine in the prevention of depressive recurrences: a double-blind study

Optimal outcomes from depression treatment are long-term recovery and, in the case of recurrent depression, prevention of new episodes. However, few data are available concerning the long-term efficacy of antidepressants in prophylactic treatment to prevent recurrences of depression. The efficacy and safety of fluoxetine 20 mg/day was evaluated in reducing the number of depressive episodes and in extending the time free of symptoms in patients with recurrent unipolar major depression. Patients with recurrent unipolar major depression according to DSM-III-R criteria and who responded to 32 weeks of open-label fluoxetine were randomly assigned to receive fluoxetine 20 mg/day (N = 70) or placebo (N = 70) for 48 weeks of double-blind maintenance treatment. Outcome measures were the percentage of recurrences and time to recurrence. Safety assessments included treatment-emergent adverse events, reasons for discontinuation, vital signs, and laboratory measures. Fluoxetine was associated with a statistically significantly smaller percentage of patients who had a recurrence compared with placebo (20% vs. 40%; chi2 analysis, p = 0.010). The symptom-free period was significantly longer for patients treated with fluoxetine versus placebo (295 vs. 192 days; Kaplan-Meier estimates, log-rank test, p = 0.002). Treatments were well tolerated during maintenance treatment. The only statistically significant difference in adverse events between treatment groups was anxiety, which was more frequent in the placebo group (fluoxetine, 12.9% vs. placebo, 30%; chi2 analysis, p = 0.013). Two placebo-treated patients and no fluoxetine-treated patients were withdrawn because of adverse events. In conclusion, fluoxetine at 20 mg/day was effective and well tolerated for the prophylactic treatment of recurrent unipolar major depression.     

Fluoxetine versus amitriptyline in the treatment of major depression with associated anxiety (anxious depression): a double-blind comparison

Although common in clinical settings, major depressive disorder with associated anxious symptoms ('anxious depression') has not been well studied in antidepressant clinical trials. The aim of this study was to compare the effects of fluoxetine versus amitriptyline in this group of patients. After a single-blind placebo run-in period of 2 weeks, patients were treated on a double-blind basis with fluoxetine or amitriptyline for 8 weeks. Assessment instruments included: 21-item Hamilton Rating Scale for Depression, Hamilton Rating Scale for Anxiety, Clinical Global Impressions, Raskin Depression Scale and Covi Anxiety Scale. A total of 157 patients were randomized to either fluoxetine or amitriptyline. Fluoxetine was given at a fixed dose of 20 mg/day and amitriptyline was given in a range of 50-250 mg/day (mean of 138.1 mg/day). Fluoxetine was comparable to amitriptyline in all efficacy measures except the HAMD sleep factor. Unwanted effects were more frequent and more severe in the amitriptyline-treated patients. Fluoxetine was comparably efficacious to amitriptyline in the treatment of major depression with associated anxiety. Since fluoxetine was far better tolerated, it is a promising alternative for this frequent and disabling condition.     

Fluoxetine Potentiation of Omega-3 Fatty Acid Antidepressant Effect: Evaluating Pharmacokinetic and Brain Fatty Acid-Related Aspects in Rodents

We previously reported that combined fluoxetine administration at antidepressant doses renders additive antidepressant effects, whereas non-antidepressant doses potentiate the omega-3 fatty acid antidepressant effect. In the present study, we aimed to evaluate putative pharmacokinetic and brain omega-3 fatty acid-related aspects for fluoxetine potentiation of omega-3 fatty acid antidepressant effect in rats. Coadministration of omega-3 fatty acids with a non-antidepressant dose of fluoxetine (1 mg/kg day) failed to affect both brain fluoxetine concentration and norfluoxetine plasma concentration profile. Fluoxetine plasma concentrations remained below the sensitivity limit of the detection method. Either antidepressant (10 mg/kg day) or non-antidepressant (1 mg/kg day) doses of fluoxetine in combination with omega-3 fatty acids increased hippocampal docosapentaenoic acid (DPA, 22:5 omega-3) levels. Although individual treatments had no effects on DPA concentration, DPA increase was higher when omega-3 were combined with the non-antidepressant dose of fluoxetine. Chronic DPA administration exerted antidepressant-like effects in the forced swimming test while increasing hippocampal docosahexaenoic (22:6 omega-3) and DPA levels. Our results suggest no pharmacokinetic interaction and reveal specific hippocampal DPA changes after fluoxetine and omega-3 combined treatments in our experimental conditions. The DPA role in the synergistic effect of fluoxetine and omega-3 combined treatments will be for sure the focus of future studies.     

Treatment of weight gain with fluoxetine in olanzapine-treated schizophrenic outpatients.

Significant weight gain is a side effect associated with olanzapine treatment in some patients. We investigated the efficacy of high-dose fluoxetine as a weight-reducing agent for patients who develop early weight gain with olanzapine treatment. Patients that gained >/=3% of their baseline weight in the initial 8 weeks of olanzapine treatment (n=31) were randomized to double-blind treatment with placebo or fluoxetine (60 mg/day). Clinical, weight, and weight-related measures were assessed. Fluoxetine failed to demonstrate weight-reducing effects (fluoxetine group: baseline mean 80.5 kg, SD=19.1, last mean=83.5 kg, SD=19.8; placebo group: baseline mean=77.1 kg, SD=12.1, last mean=78.8 kg, SD=10.6; F=1.3; df=1, 18; p=0.3). There were no differential effects in psychopathology, extrapyramidal side effects or weight-related measures between the placebo and fluoxetine groups. Serotonin reuptake inhibitors are probably not a practical option to counteract weight gain induced by atypical antipsychotics. Atypical-induced weight gain may result from mechanisms other than 5HT reuptake blockade.     

The impact of antidepressants on sleep and anxiety: a comparative study of fluoxetine and dothiepin using the Leeds Sleep Evaluation Questionnaire

Fluoxetine (20 mg) was compared to dothiepin (150 mg) in a multicentre, prospective, double blind, randomised clinical trial involving 125 patients with major depression treated for an initial phase of 6 weeks and then followed up for a further 6 months. There was no difference in the efficacy of the two drugs based on the results of established rating scales (MADRS, HAM-D, BPRS). The impact of both drugs on sleep measured using the Leeds Sleep Evaluation Questionnaire showed no significant differences between treatments, however drowsiness and disturbed sleep were reported more frequently as side effects with dothiepin. Symptoms of anxiety responded equally well to both treatments. The short term and long term tolerability of dothiepin was inferior to that of fluoxetine. The place of dothiepin in treatment should be reassessed in the light of its anticholinergic adverse event profile, particularly in the elderly. Copyright 2000 John Wiley & Sons, Ltd.     

Comparative effects of fluoxetine and amitriptyline on cardiac function.

1. The effects of fluoxetine and amitriptyline on the electrocardiogram (ECG) and systolic time intervals (STIs) were measured during a double-blind parallel-group study in depressed patients. 2. ECGs and STIs were measured after a 1 week placebo run-in, following 1 week's treatment with fluoxetine 40 mg daily or amitriptyline 100 mg daily, and then after 3 weeks' treatment with fluoxetine 60-80 mg daily or amitriptyline 150-200 mg daily. 3. Fluoxetine had no effect on the ECG or STIs at any dose. Amitriptyline 150-200 mg daily shortened the sinus cycle length by a mean of 12%, prolonged the PR interval by 8% and the QRS duration by 10%. Amitriptyline did not significantly alter the STIs.     

A randomized controlled trial of fluoxetine in the treatment of cocaine dependence among methadone-maintained patients

Background

Cocaine abuse and dependence continue to be widespread. Currently, there are no pharmacotherapies shown to be effective in the treatment of cocaine dependence.

Methods

A 33-week outpatient clinical trial of fluoxetine (60 mg/day, po) for cocaine dependence that incorporated abstinence-contingent voucher incentives was conducted. Participants (N = 145) were both cocaine and opioid dependent and treated with methadone. A stratified randomization procedure assigned subjects to one of four conditions: fluoxetine plus voucher incentives (FV), placebo plus voucher incentives (PV), fluoxetine without vouchers (F), and placebo without vouchers (P). Dosing of fluoxetine/placebo was double blind. Primary outcomes were treatment retention and cocaine use based on thrice-weekly urine testing.

Results

The PV group had the longest treatment retention (M = 165 days) and lowest probability of cocaine use. The adjusted predicted probabilities of cocaine use were 65% in the P group, 60% in the F group, 56% in the FV group, and 31% in the PV group.

Conclusions

Fluoxetine was not efficacious in reducing cocaine use in patients dually dependent on cocaine and opioids.     

Modulation of the Critical Flicker Fusion effects of serotonin reuptake inhibitors by concomitant pupillary changes

RATIONALE: Serotonin reuptake inhibitors (SSRIs) have been attributed CNS-activating properties based on their ability to elevate the Critical Flicker Fusion (CFF) threshold. However, such an interpretation may be questioned since CFF elevations may also be due to SSRI-induced increases in pupil diameter. OBJECTIVES: The effect of pupillary changes on CFF assessment following SSRI administration was investigated in a double blind, crossover study. METHODS: During three periods of 15 days, 21 healthy men and women (30-50 years) received sertraline (50 mg on days 1-8, 100 mg on days 9-15), citalopram (20 mg on days 1-8, 40 mg on days 9-15) and placebo. Assessments were done on days 1, 8 and 15 and consisted of pupillary measurements and CFF assessments with and without pupillary control (a 2-mm artificial pupil) using the Leeds Psychomotor Tester. RESULTS: Both SSRIs induced an acute and steady increase in pupil diameters. CFF thresholds were depressed following acute administration of sertraline and citalopram, but this was only apparent when a control was made for the pupillary changes. No CFF effects were seen at day 8, but CFF was again reduced at day 15, with and without control for pupil size. CONCLUSIONS: Mydriasis masked the detrimental effects of both SSRIs on CFF during the acute assessments. Our results raise questions regarding the validity of the assessment of the behavioural toxicity of SSRIs based on CFF measurements without ample control for pupil size, especially when these concern acute measurements.     

A double-blind comparative study of fluoxetine and dothiepin in the treatment of depression in general practice

Fluoxetine, a selective inhibitor of 5-HT uptake, was compared to dothiepin in a double-blind study of 6 weeks duration in 100 depressed patients (male and female) drawn from 8 general practices. Only those who scored at least 17 on the first 17 questions of the Hamilton Psychiatric Rating Scale for Depression (HAM-D) were selected. Both groups improved throughout the trial, though the dothiepin treated patients tended to improve quicker. However, by the end of the trial there was no statistically significant difference between the 2 groups. Subset analyses of HAM-D scores associated with anxiety and sleep revealed no statistically significant differences between the 2 treatments though improvement in anxiety scores was marginally greater for those receiving fluoxetine by the end of the trial. Other global assessments by patients and doctors confirmed the changes in HAM-D scores. Statistically significant weight changes occurred between visits 1 and 5. Whereas fluoxetine-treated patients lost weight (p less than 0.05), dothiepin-treated patients gained weight (p = 0.05) over this period. Adverse effects were reported in 27 patients given fluoxetine and 20 dothiepin. Of these, 14 fluoxetine and 7 dothiepin-treated patients withdrew before the end of the trial. The most common adverse effects were nausea, vomiting and diarrhoea in the fluoxetine group and tiredness, drowsiness and diarrhoea in the dothiepin group. There were no haematological or clinical chemistry changes.     

Increased remission rates with venlafaxine compared with fluoxetine in hospitalized patients with major depression and melancholia

This was a 6-week, double-blind, randomized trial of the efficacy and tolerability of venlafaxine and fluoxetine in 109 patients with major depression and melancholia. Hospitalized and day care patients with DSM-IV major depression and melancholia and a baseline Montgomery-Asberg Depression Rating Scale (MADRS) score of > or = 25 were eligible. The doses were venlafaxine 75 mg/day or fluoxetine 20 mg/day from days 1-4, venlafaxine 150 mg/day or fluoxetine 40 mg/day from days 5-10, and venlafaxine 225 mg/day or fluoxetine 60 mg/day from days 11-42. The intention-to-treat analyses included 55 patients on venlafaxine and 54 on fluoxetine. At the final evaluation, 70% of patients with venlafaxine and 66% with fluoxetine had > or = 50% reduction in the MADRS score, and 70% with venlafaxine and 62% with fluoxetine had a Clinical Global Impression (CGI) score of 1 or 2. A CGI improvement score of 1 was observed in 51% of patients with venlafaxine and 32% with fluoxetine (P = 0.018). A final Hamilton Depression Rating Scale (HAM-D) score < 7 was attained in 41% of venlafaxine-treated and 36% of fluoxetine-treated patients. Overall, 22% of patients in each group discontinued therapy, but only 5% on venlafaxine and 9% on fluoxetine discontinued for adverse events. Nausea was reported in 5.5% of venlafaxine-treated patients and 14.8% of fluoxetine-treated patients. Venlafaxine was effective and well tolerated for treating inpatients with major depression and melancholia. Based on remission criteria (HAM-D < 7 or CGI of 1), venlafaxine was superior to fluoxetine.     

Distribution and excretion of fluoxetine and norfluoxetine in human milk

AIMS: To characterize milk/plasma (M/P) ratio and infant dose, for fluoxetine and norfluoxetine, in breast-feeding women taking fluoxetine for the treatment of depression, and to determine the plasma concentration of these drugs in their infants. METHODS: Fourteen women (mean age 32.2 years) taking fluoxetine (mean dose 0.51 mg kg-1 day-1 ) and their infants (mean age 3.4 months) were studied. Fluoxetine and norfluoxetine in plasma and milk were measured by high-performance liquid chromatography over a 24 h dose interval in four patients, and by single point data collection in 10 patients. Infant exposure was estimated as the product of estimated milk production, and average drug concentration in milk, normalized to body weight and expressed as a percentage of the weight-adjusted maternal dose. RESULTS: Mean M/P values of 0.68 (95% CI 0.52-0.84) and 0.56 (95% CI 0.35-0.77) were calculated for fluoxetine and norfluoxetine, respectively. Mean total infant exposure (fluoxetine equivalents) was estimated to be 6.81% (range 2.15-12%) of the weight-adjusted maternal dose of fluoxetine. Contributions from fluoxetine and norfluoxetine were approximately equal. Fluoxetine (range 20-252 microgram l-1 ) was detected in five of the nine infants from whom samples were collected, and norfluoxetine (range 17-187 microgram l-1 ) was detected in seven of the nine infants. The highest of these concentrations was about 70% of the maternal plasma concentrations. CONCLUSIONS: The mean combined dose of fluoxetine and norfluoxetine transmitted to infants via breast milk is below the 10% notional level of concern. However, there was considerable interpatient variability in estimated infant dose and in some of the patients, the dose was >10%. Further, since adverse effects have been observed in breast-fed infants, careful monitoring of the infants is mandatory. Neonates exposed to these drugs in utero had higher concentrations of fluoxetine and norfluoxetine and are at greater risk of adverse effects.     

Fluoxetine: a serotonin-specific, second-generation antidepressant

Fluoxetine is a bicyclic antidepressant that is a specific and potent inhibitor of the presynaptic reuptake of serotonin. It has essentially no effect on the reuptake of norepinephrine or other neurotransmitters. Similarly, it has negligible binding affinity for neurotransmitter receptor sites. It is well absorbed after oral administration, with absolute bioavailability in dogs of approximately 72 +/- 27.6%. The mean Tmax is between 4 and 8 hours, and it is approximately 94% protein bound. After a single dose, the elimination half-life is 1-3 days. After long-term administration, the elimination half-life averages 4 days. Its pharmacokinetics appear nonlinear. It is metabolized to an active metabolite norfluoxetine, which is also specific for the inhibition of serotonin reuptake. Norfluoxetine's elimination half-life averaged 7 days after long-term administration. Little is known about potential drug interactions; however, fluoxetine appears to have minimal clinically relevant interactions. Fluoxetine is indicated in the treatment of major depression. Its efficacy is comparable to the tricyclics and it has a similar onset of action. Although doses as high as 80 mg/day have been used, the optimal dosage range appears to be 20-40 mg once daily. Fluoxetine has been used with success in obsessive-compulsive disorder and intention myoclonus, however, its use in these disorders remains investigational. The frequency of side effects is low and dose related; the most common effects are nausea, anxiety, insomnia, anorexia, diarrhea, nervousness, and headache. Eight reports of intentional overdose with fluoxetine alone resulted in no deaths and mild adverse effects. It will be marketed as 20-mg capsules under the brand name of Prozac. Although fluoxetine should be added to formularies, its use should be reserved for treatment of those who do not respond to or do not tolerate tricyclic agents.     

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.