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Biomedical subjects

B Vandel

Publications and source records attributed to B Vandel.

At least 19 recordsLinked to original sources
PubMed1992

Tricyclic antidepressant plasma levels after fluoxetine addition.

After a review of a pharmacokinetic interaction between tricyclic antidepressants (TCA) and fluoxetine the authors report their own data. They confirm the existence of an interaction of TCA with fluoxetine, in clinical practice, but the fluoxetine was not associated in all cases with a marked increase of TCA plasma levels. The increase appeared especially high with clomipramine (n = 4) and imipramine (n = 3), and lower or dose-dependent with amitriptyline (n = 4). The pharmacokinetic change did not induce side effects in the patients, even when the total TCA plasma level increased to 965 (clomipramine) or 785 (imipramine) ng/ml. The authors then discuss the clinical implication and the possible mechanism of action.

Adult↗
PubMed1990

Desipramine induces cardiac beta-adrenergic sensitivity decrease in major depressed patients without relationship to therapeutic response.

Nineteen major depressed inpatients were treated over three weeks with desipramine. Cardiac beta-adrenergic receptor sensitivity was evaluated by an isoproterenol test before and after the three-week treatment. Desipramine induced a beta-adrenergic sensitivity decrease in most of the patients: I 20 (isoproterenol dose necessary to increase by 20 beats/min. the basal heart rate) before treatment: 89 +/- 37 ng/kg (mean +/- SD); after treatment: 170 +/- 135 ng/kg; p(t) less than 0.03. Despite a linear relationship between pretreatment beta-adrenergic sensitivity and post-treatment clinical state, there was no relation between post-treatment cardiac beta-adrenergic sensitivity and therapeutic response or even desipramine plasma levels.

Depressive Disorder↗
PubMed1989

Amitriptyline: linear or nonlinear kinetics in every day practice?

The linearity of the (AMT) kinetics of amitriptyline has been tested in 135 depressed dosed twice daily by measuring plasma. Their (AMT) and nortriptyline (NT) levels under steady-state conditions. The AMT concentration/dose ratios at low and high dosages were not significantly different and there was a linear relationship between the dose ratios and the concentration ratios. No change in the metabolic ratio (AMT/NT) was observed between the two dosages. Although the results are consistent with linear AMT kinetics, there may have been nonlinear kinetics in some patients as the ratio between the concentration/dose ratios in them at low and high dosages was greater than one. Those patients were characterized by a low concentration/dose ratio at low dosage. No clinical adverse effect appeared in the study.

Amitriptyline↗
PubMed1989

Desipramine dose prediction based on 24-hour single-dose levels: feasibility and validity.

The authors present a prospective study of a rapid desipramine dose adjustment on the basis of a 24-hour plasma concentration after a single 150 mg dose. For this, they use a prediction table constructed from data in the literature showing strong correlation between steady-state plasma levels and 24-hour single-dose levels. Despite the fact that desipramine action is not always linear, the method appears to be feasible and valid. In an attempt to reach a 150 ng/ml level, the authors obtained steady-state levels ranging from 85 to 317 ng/ml, with 14 of the 19 patients in the range between 125 and 250 ng/ml. Moreover, 11 of the 19 patients received a daily dose of 250 mg or more desipramine from the third day of treatment onward; in ten of these cases, this dose had been adapted.

Adult↗
PubMed1989

Cardiac beta-adrenergic sensitivity in depression: relation with endogenous subtype and desipramine response.

The authors studied the responsiveness of cardiac beta-receptors to isoproterenol, a noradrenergic agonist, in 29 depressed patients and 13 control subjects. They showed a significantly lower sensitivity in depressed patients as compared with the control subjects. Focussing on the group of depressed patients without antidepressant treatment in the month preceding the study (n = 15) in order to avoid a bias, the following significant results were obtained: cardiac beta-adrenergic receptor sensitivity was lower in patients suffering from endogenous depression than in those suffering from reactive depression (as classified by Newcastle Scale). There was a negative linear relation between cardiac beta-adrenergic sensitivity and the posttreatment clinical state (as expressed by the MADRS score) for the 9 patients who ended a 3-week desipramine treatment period.

Adjustment Disorders↗
PubMed1989

A study of the interaction of viloxazine with theophylline.

The effect of viloxazine on the pharmacokinetics of theophylline was studied in eight healthy volunteers. Theophylline 200 mg/day (théophylline Bruneau 100 mg tablets) was administered on day 1; after a 3-day washout period, viloxazine 300 mg/day (Vivalan 100 mg tablets) was administered orally from days 5 to 7. On day 8, theophylline 200 mg and viloxazine 100 mg were concomitantly administered. The pharmacokinetic parameters of theophylline alone and after coadministration of viloxazine were determined. Viloxazine significantly increased the plasma concentrations (p less than 0.01) and the area-under-the-curve values (p less than 0.01) of theophylline and decreased its body clearance (p less than 0.05). Our results suggest that the dosage of theophylline should be decreased and its plasma concentrations monitored when viloxazine is prescribed.

Adult↗
PubMed1986

Biotransformation of amitriptyline in man: interaction with phenothiazines.

The biotransformation modification of amitriptyline by phenothiazines has been studied in 65 depressive inpatients. Thirty-four of them were treated with oral amitriptyline and 31 with a combination of amitriptyline and phenothiazine. Urinary and plasmatic results showed a decrease in hydroxylated metabolites of amitriptyline (OHAMTc and OHAMT) in patients with added phenothiazine.

Adult↗
PubMed1986

[Pharmacokinetic factors and resistance to antidepressant treatment].

A number of treatment failures occurring during antidepressant treatment may be related to the pharmacokinetics of the drug used. In fact, numerous factors are able to modify the fate of the antidepressant in the body. These factors may involve the absorption, distribution, biotransformation or elimination of the drug. The reality of these problems is illustrated by a number of clinical case reports. Such modifications lead to a variation in the quantity of drug available to exert its antidepressant action at the sites responsible for the pharmacodynamic effects. This raises the possible value of defining, and then using in practice, the therapeutic zone of the plasma concentrations of the antidepressant used, below and above which a poor therapeutic response is likely. Modern analytical techniques actually allow the routine analysis of plasma concentrations of a number of antidepressants, resulting in a more rational approach to drug therapy and a decrease in the number of depressions resistant to antidepressant treatments.

Antidepressive Agents↗
PubMed1985

Biological markers in depression. Monoamine metabolites in urine of depressed patients and normal subjects.

Urinary elimination of HVA, MHPG and 5-HIAA was studied in 22 depressed inpatients before and after 28 days of antidepressant treatment. Mean values did not change significantly during treatment, and were not related significantly to recovery in patients. Some marked changes in urinary metabolite levels were, however, observed in individual patients, and could be related to changes in their depression. The direction of change in urinary monoamine metabolites during treatment was associated with pretreatment levels, in that high pretreatment values tended to decrease whereas low pretreatment levels tended to increase.

Adult↗
PubMed1978

Clinical response and plasma concentration of amitriptyline and its metabolite nortriptyline.

Plasma levels of amitriptyline and nortriptyline were measured twice weekly in 62 patients treated for three weeks with i.m. amitriptyline 120 mg/day. In half the patients the ratio of amitriptyline to nortriptyline was under 1 and in the other half it was greater than 1. 30 of these 62 patients were clinically monitored with the Hamilton Rating Scale and the side effects of the drug were recorded. There was no correlation between plasma level of the drug and its side effects, but there was a statistically significant curvilinear correlation between the plasma levels of amitriptyline plus nortriptyline and nortriptyline alone, and the clinical effect. The practical value of this type of investigation was demonstrated by showing that patients whose drug plasma level was not in the therapeutic range, were clinically improved after adjustment of the dose. The plasma level of amitriptyline plus nortriptyline must lie between 60 to 220 ng/ml, and that of nortriptyline between 60 to 140 ng/ml, to obtain the best clinical effect. Associated treatments, age, weight and sex of patients, and the type of depression did not appear significantly to affect the plasma level of the drug.

Adult↗
PubMedDate not supplied

Debrisoquine and dextromethorphan phenotyping and antidepressant treatment.

The correlation between debrisoquine and dextromethorphan oxidation polymorphism was studied in 16 depressed in-patients. There was a close correlation between both phenotypes (r = 0.81 p less than 0.0017). During a treatment with amitriptyline during two weeks there was no significant modification of the dextromethorphan polymorphism. In the same way, the association of amitriptyline and toloxatone during two other weeks did not change this polymorphism in a significant way, even if there was a non significant shift towards higher values of the dextromethorphan metabolic ratio.

Adult↗
PubMedDate not supplied

[Drug interactions of cyclosporine. Literature review].

The cyclosporine is widely used as an immuno-suppressive agent in association with others drugs. Its narrow therapeutic range requires frequent monitoring. We suggest a literature review of suspected or confirmed drug interactions. The classification is presented as: absorption interactions; pharmacokinetic interactions in antiinfectious, anticonvulsants, cardiovascular drugs, H2 antagonists agents, hormonotherapy; pharmacodynamic interactions associated to increased cyclosporine nephrotoxicity.

Animals↗