Effects of zimeldine, mianserin and amitriptyline on psychomotor skills and their interaction with ethanol a placebo controlled cross-over study

Pharmacokinetic and pharmacodynamic drug interactions with ethanol (alcohol)

Ethanol (alcohol) is one of the most widely used legal drugs in the world. Ethanol is metabolized by alcohol dehydrogenase (ADH) and the cytochrome P450 (CYP) 2E1 drug-metabolizing enzyme that is also responsible for the biotransformation of xenobiotics and fatty acids. Drugs that inhibit ADH or CYP2E1 are the most likely theoretical compounds that would lead to a clinically significant pharmacokinetic interaction with ethanol, which include only a limited number of drugs. Acute ethanol primarily alters the pharmacokinetics of other drugs by changing the rate and extent of absorption, with more limited effects on clearance. Both acute and chronic ethanol use can cause transient changes to many physiologic responses in different organ systems such as hypotension and impairment of motor and cognitive functions, resulting in both pharmacokinetic and pharmacodynamic interactions. Evaluating drug interactions with long-term use of ethanol is uniquely challenging. Specifically, it is difficult to distinguish between the effects of long-term ethanol use on liver pathology and chronic malnutrition. Ethanol-induced liver disease results in decreased activity of hepatic metabolic enzymes and changes in protein binding. Clinical studies that include patients with chronic alcohol use may be evaluating the effects of mild cirrhosis on liver metabolism, and not just ethanol itself. The definition of chronic alcohol use is very inconsistent, which greatly affects the quality of the data and clinical application of the results. Our study of the literature has shown that a significantly higher volume of clinical studies have focused on the pharmacokinetic interactions of ethanol and other drugs. The data on pharmacodynamic interactions are more limited and future research addressing pharmacodynamic interactions with ethanol, especially regarding the non-central nervous system effects, is much needed.

Effects of short-term moderate alcohol administration on oxidative stress and nutritional status in healthy males

The effects of moderate amounts of different alcoholic beverages on oxidative stress and nutritional parameters were investigated in 40 healthy subjects. Ethanol 40 g/day was administered at the two main meals for 30 days by beer (group A), wine (group B) or spirit (group C); controls (group D) maintaned abstinence. Malondyaldeide (MDA), adenosine-triphosphate (ATP), reduced-glutathione (GSH), E-vitamin and nutritional status were evaluated at the start (T0) and the end (T1) of the study. At T1 controls did not present significant changes in the assessed parameters, while a significant increase of malondyaldeide (MDA) and a significant decrease of reduced-glutathione and E-vitamin in group A, B and C and of ATP in group C were observed. Fat mass (FM) increased slightly in group A and B and decreased in group C. Ethanol decreased antioxidant parameters and increased lipoperoxidation parameters. However some of these changes appeared attenuated when ethanol was consumed in beer or wine. Finally, short-term moderate ethanol intake appeared to influence the FM, although it was not able to significantly affect nutritional or body composition.

Acute and subchronic effects of amitriptyline 25mg on actual driving in chronic neuropathic pain patients

The acute and subchronic effects of low doses nocturnally administered amitriptyline were compared to placebo in a double-blind crossover randomized study on driving ability and driving-related skills involving seven chronic neuropathic pain patients. Performance testing occurred at the first and last day of each 15-day drug administration period, which was preceded by a 6-day washout phase. A standardized method of measuring driving ability, the on-the-road driving test, was performed on all visits. Patients were instructed to drive with a steady lateral position while maintaining a constant speed of 95 km/h. The primary outcome of the driving test is the Standard Deviation of Lateral Position (SDLP, cm), which is an index of weaving of the car. At the first treatment day, driving performance was significantly impaired in patients after nocturnal administration of 25 mg amitriptyline compared to placebo. The increase in SDLP of 3 cm was higher than the increment generally observed with a blood alcohol concentration of 0.5 mg/ml or higher, the legal limit for driving in many countries. Also, reaction times on a memory test were significantly increased, indicating worse performance after acute treatment of amitriptyline compared to placebo. In contrast, after 2 weeks of treatment, no significant differences were found between amitriptyline and placebo, suggesting that tolerance had developed to the impairing effects of amitriptyline.

The effects of St John's wort extract on heart rate variability, cognitive function and quantitative EEG: a comparison with amitriptyline and placebo in healthy men

AIMS

To compare the effects of multiple dosing with St John's wort (Hypericum perforatum) extract and amitriptyline on heart rate variability, cognitive function and quantitative EEG (qEEG) with placebo in healthy humans.

METHODS

A randomized, double-blind, cross over study of 12 healthy male volunteers. Subjects orally received capsules with 255-285 mg St John's wort extract (900 micro g hypericin content), 25 mg amitriptyline and placebo three times daily for periods of 14 days each with at least 14 days between. The doses of amitriptyline and St John's wort extract are comparable with respect to their antidepressant activity. Compliance was confirmed by coadministration of 10 mg of riboflavin with each capsule and detection of urinary vitamin B2 on treatment day 11 with high performance liquid chromatography. Measurements of heart rate variability, psychometric tests and qEEG were performed before start of medication and repeatedly on the last treatment day.

RESULTS

St John's wort extract did not affect heart rate variability (HRV) whereas amitripytline significantly decreased it: the difference in the percentage number of adjacent RR intervals> 50 ms (pNN50) was 8.6 (-2.6, 19.9; mean; 95% confidence interval) between St John's wort extract and placebo and -17.6 (-24.7, -10.4) between amitriptyline and placebo. Neither St John's wort extract nor amitriptyline had an influence on cognitive performance such as choice reaction, psychomotor coordination, short-term memory and responsiveness to distractive stimuli. Amitriptyline but not St John's wort extract decreased self rated activity (P < 0.05). Both drugs caused significant qEEG changes. St John's wort extract increased theta power density. Amitriptyline increased theta as well as fast alpha power density.

CONCLUSIONS

Multiple doses of St John's wort extract do not affect heart rate variability nor cognitive function. Chronic administration of amitriptyline causes a decrement of HRV and subjective sedation but it does not impair cognitive performance.

Long-term effects of antidepressants on balance, equilibrium, and postural reflexes

To assess the long-term effects of antidepressant medication on balance, equilibrium, and postural reflexes, we studied 30 patients, ages 20-76 years, who had a diagnosis of depressive disorder (as defined by DSM-III-R criteria) and had been treated with tricyclic antidepressants (TCAs) or selective serotonin reuptake inhibitors (SSRIs) for > or = 1 year. They were assessed by a Balance Master System. The assessment included three tasks: static balance, rhythmic weight shift, and limits of stability. When compared with 30 nonhospitalized healthy controls (of comparable age and the same sex), patients who took TCAs showed impaired balance function in all main indices. The results suggest that the impairment of balance function includes motor coordination, fine-motor control, postural reflexes, maintaining equilibrium, and reaction time. No obvious impairment of balance function was observed in patients who took SSRIs.

Drug and ethanol effects on the clinical test for drunkenness: single doses of ethanol, hypnotic drugs and antidepressant drugs

The clinical test for drunkenness has been used in Finland to detect alcohol-induced impairment of driving fitness. Since the data about the effects of psychotropic drugs on the clinical test for drunkenness are limited, this test was administered in two randomized double-blind cross-over trials with 12 subjects in each. The clinical tests were done at 2 hr and 5 hr after drug intake. For comparison, the representative laboratory tests used were digit symbol substitution, simulated driving (tracking+reaction time) and "global psychomotor performance". In Trial I, 15 mg of diazepam, 50 mg of amitriptyline and 15 mg of mirtazepine, each drug administered alone, had minor effects on the clinical tests. Compared to the placebo, mirtazepine, and diazepam, diazepam+mirtazepine impaired performance on the motor subtests at 2 hr. The tracking error percentage was increased by amitriptyline, diazepam+amitriptyline, and diazepam+mirtazepine up to 4.5 hr. In Trial II with 7.5 mg of zopiclone, 0.25 mg of triazolam and 0.8 g/kg of ethanol, ethanol alone and hypnotic-ethanol combinations impaired performance on the motor and vestibular subtests, whereas single drug intake had minor effects. Tracking was more sensitive to drugs than to ethanol. In conclusion, the clinical test for drunkenness detected impaired performance following single doses of ethanol or drug-ethanol combinations better than it detected impaired performance following moderate doses of drugs or drug-drug combinations, respectively.

Cochleotoxicity due to Mianserin hydrochloride

A patient who developed bilateral tinnitus and symmetrical high frequency sensorineural hearing loss due to therapy with the anti-depressant Mianserin hydrochloride is presented together with a short review of available literature.

Echocardiographic and psychometric effects of amitriptyline or imipramine plus alcohol

The echocardiographic and psychometric effects of amitriptyline or imipramine combined with alcohol have been studied in a double-blind cross-over trial in 7 healthy volunteers. Amitriptyline or imipramine 25 mg b.d. were given for three days and then the dose was doubled. On Days 1 and 10-13 echocardiographic measurements were done, and on Day 15 psychomotor tests were performed. Ethanol 1 g/kg in each session was administered 1 h after drug intake. Alcohol alone increased heart rate and decreased the systolic blood pressure and ejection fraction. It also impaired most of the psychomotor measures, horizontal nystagmus being the most sensitive test. On Day 1, the first dose of imipramine decreased the heart rate and increased diastolic blood pressure. These effects were partly counteracted by alcohol. Imipramine + alcohol decreased the WSTR. Amitriptyline alone did not affect the echocardiographic findings on Day 1. In combination with alcohol it reduced cardiac output and prolonged PEP, and increased the PEP/LVET ratio. During subacute treatment (Days 10-13) WSTR was increased by both antidepressants, but only amitriptyline increased the heart rate. Unlike imipramine + alcohol, amitriptyline + alcohol decreased WSTR and MCSR. Digit symbol substitution was the only pschometric test in which the alcohol effect was clearly enhanced by both amitriptyline and imipramine.

Evaluation and comparison of the interaction between alcohol and moclobemide or clomipramine in healthy subjects

The interaction of clomipramine and moclobemide with alcohol was compared in a double blind parallel groups study in 24 healthy volunteers. Moclobemide was given at the highest recommended therapeutic dose (200 mg t.i.d.) and clomipramine in a subtherapeutic dose (25 mg b.i.d.) because of its poor tolerance in healthy subjects. Psychometric evaluations were performed during a placebo run-in phase; after a 5-day treatment period; assessments were made before, and again 1 h and 4 h after alcohol ingestion. Alcohol doses were pre-determined for each subject in order to produce a blood alcohol concentration of 0.6 g/l 1 h after alcohol intake and this individual alcohol dose was given on test days. The day before alcohol intake tests for autonomic functions were made to assess the anticholinergic effects of the drugs. Alcohol significantly increased body sway, decreased critical flicker fusion frequency, prolonged choice reaction time, impaired copying skills, impaired memory and increased the subjective feelings of satisfaction and tension. Drugs increased the effect of alcohol on body sway and this was essentially due to clomipramine. Clomipramine both without and with alcohol increased body sway, prolonged choice reaction time more than did moclobemide. Clomipramine seemed to diminish alcohol-induced memory impairment in one of the memory tests used. Subjects taking clomipramine had significantly more adverse effects after alcohol ingestion than did subjects of the moclobemide group. In contrast to moclobemide, clomipramine produced a moderate but significant drop in standing systolic blood pressure and a clear inhibition of salivary excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Actions and interactions of psychotropic drugs on human performance and mood: single doses of ORG 3770, amitriptyline, and diazepam

Actions and interactions of two antidepressants and diazepam on human skilled performance and mood were studied in a randomized double-blind cross-over trial with single oral doses of 50 mg amitriptyline (AMI), 15 mg Org 3770 (ORG) and placebo, given alone and in combination with 15 mg diazepam (DZ) to 12 young healthy subjects at one-week intervals. Objective tests (digit substitution, tapping, flicker fusion, Maddox wing, tracking, choice reactions, body sway, memory) and subjective assessments (visual analogue scale) were performed at baseline and 1.5, 3, 4.5 and 6 hours after drug administration. Side-effects were reported, blood pressure and heart rate measured and blood samples taken after each testing run. Placebo was nearly inert on performance and mood. DZ impaired some objective skills and showed sedative effects in the subjective tests. AMI produced sedation and impaired coordination as well as cognitive performance (digit substitution), most clearly at 3 to 4.5 hr. ORG resembled AMI in impairing objective and subjective performance, however, not necessarily in the same tests. Their combined effects with DZ were additive in objective tests but less additive in subjective tests. The drug combinations, but not any single drug, impaired learning acquisition. Plasma concentrations of the drugs given alone were about as expected, without important interactions. We conclude that the combinations of benzodiazepines with the antidepressants used impair skilled performance but may not cause major hazards.

Serotonin uptake blockers and voluntary alcohol consumption. A review of recent studies

Previous research demonstrated that serotonin uptake blockers (e.g., zimeldine, sertraline, fluoxetine) reduce voluntary ethanol consumption in rats and humans. However, the mechanism of action of these compounds is not well understood. It has been suggested, for example, that serotonin uptake blockade interferes with the processes that mediate the reinforcement derived from ethanol ingestion. On the other hand, there is considerable experimental evidence that suggests that the effects on alcohol intake may be an expression of a more general inhibitory role that serotonin plays in consummatory behavior. This chapter presents evidence that suggests that serotonin uptake blockers may affect ethanol intake, in part via a reduction of food intake. Current issues concerning the central versus peripheral mediation of these effects, receptor specificity, as well as alternate mechanisms of action are considered.

Interactions of antidepressants and ethanol on spontaneous locomotor activity and rotarod performance in NMRI and C57BL/6 mice

In order to find appropriate doses for studying antidepressant-ethanol interaction in two mouse strains, spontaneous locomotor activity and rotarod performance were first studied in NMRI mice after amitriptyline 3-30 mg/kg, mianserin 3-30 mg/kg, nomifensine 1- 10 mg/kg, citalopram 3-100 mg/kg, and ethanol 1-3 g/kg intraperitoneally. Ethanol increased significantly locomotor activity at 1 g/kg and impaired rotarod performance at 2 and 3 g/kg. Amitriptyline and mianserin decreased dose-dependently locomotor activity at doses ≥ 10 mg/kg. Nomifensine and citalopram increased locomotor activity at 10 mg/kg and citalopram 100 mg/kg decreased it. Rotarod performance was affected only by amitriptyline 10 and 30 mg/kg and citalopram 100 mg/kg, which impaired performance. Interaction studies with the two strains using amitriptyline, mianserin, nomifensine and citalopram 10 mg/kg and ethanol 1 g/kg showed that C57BL/6 mice were less sensitive than NMRI mice to the stimu lating effects of ethanol and more sensitive to impairment of rotarod performance by amitrip tyline and mianserin. C57BL/6 mice had a significantly poorer baseline performance on rotarod, and the citalopram plus ethanol combination impaired their performance severely, although drugs alone did not impair this test. The results suggest that decreased locomotor activity as a measure of antidepressant-induced sedation does not parallel with impaired performance on rotarod and that significant strain differences can be seen in psy chopharmacological tests and responses to drugs in mice.

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

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.

Acute effects of amitriptyline on human performance and interactions with diazepam

The effects of psychomotor performance and attention of amitriptyline 75 mg administered without and with diazepam 10 mg have been investigated in 12 healthy subjects. The effects of the compounds were evaluated by objective tests (measurement of body sway, critical flicker fusion, visual reaction time, tachistoscopy, short term visual memory, tapping test, arithmetical calculation and Clement's code) and subjective measurements (visual analogue scales and side effects questionnaire). Measurements were taken before treatment and after 1, 3, 6, 8 and 24 h. Placebo did not affect either the objective or the subjective measurements. Diazepam caused a reduction in attention and performance after 1 h which had disappeared at 3 h. Amitriptyline caused a marked reduction in attention and performance, reaching a peak 3 hours after drug administration and persisting until 8 h. the deterioration in vigilance induced by amitriptyline was potentiated by concomitant diazepam.

A comparative study of the interactions of alcohol with amitriptyline, fluoxetine and placebo in normal subjects

1. Twelve normal volunteer subjects were given amitriptyline, fluoxetine and placebo in clinically relevant doses, each for a period of 7 days. A minimum of 28 days intervened between each drug treatment. 2. A battery of physiological, psychomotor and subjective tests was administered before drugs and on days 4 and 8. 3. On day 8 a measured dose of alcohol was given and the tests repeated 1 hour and 3 hours later. 4. Before alcohol, little effect was shown on physiological or psychomotor activity. Subjective ratings indicated that amitriptyline was less-well tolerated than fluoxetine. 5. Significant differences were found for many measures after alcohol but there were few differences with respect to the drugs.

Acute comparison of clovoxamine and mianserin, alone and in combination with ethanol, on human psychomotor performance

Objective and subjective effects on human performance of clovoxamine and mianserin were measured in 12 student volunteers who participated in 12 test sessions and received single doses of clovoxamine 50 mg, 100 mg and 150 mg, mianserin 20 mg, and placebo in a double-blind and cross-over manner. Each test drug was given twice, both in combination with alcohol 0.8 g/kg and with a non-alcoholic drink. The tests included tracking, body balance, flicker fusion, horizontal nystagmus, digit symbol substitution, recall memory, and subjective assessments on visual analogue scales. Mianserin and alcohol impaired objective performance in most tests, and their combination showed at least an additive effect. Alcohol counteracted rather than increased mianserin-induced subjective sedation. Clovoxamine neither differed significantly from placebo nor increased alcohol effects. On the contrary, clovoxamine 150 mg reduced significantly alcohol-induced body sway. No evidence of pharmacokinetic interactions were found between the study drugs and alcohol.

Benzodiazepines, but not antidepressants or neuroleptics, induce dose-dependent development of tolerance to lorazepam in psychiatric patients

Psychomotor effects of oral lorazepam 3 mg were studied in psychiatric patients stratified into four groups: 1) a group of six patients with no previous use of psychotrophic drugs (NoD), 2) a group of 12 patients treated with antidepressants and/or neuroleptics (PsyD), 3) a group of 10 patients treated with low doses of benzodiazepines (BZs) (lowBZ), and 4) a group of nine patients treated with high doses of BZs (high BZ). Similar objective psychomotor tests and subjective assessments were administered under single-blind conditions to all treatment groups at baseline, after intake of placebo, and after intake of 3 mg lorazepam. Both lorazepam (CGC) and total BZs (bioassay) in serum were assayed. The results demonstrate that treatment with BZs induce dose-dependent development of tolerance to psychomotor effects of lorazepam. Antidepressants and neuroleptics failed to induce cross-tolerance to lorazepam. The rise in serum lorazepam concentrations after lorazepam intake was similar (about 28 micrograms/l) in all treatment groups, suggesting a functional, not dispositional, tolerance. However, the initial learning effect in psychomotor performance was poorer among BZ users than among others.