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Biomedical subjects

M Molimard

Publications and source records attributed to M Molimard.

At least 19 recordsLinked to original sources
PubMed2006

Effect of indacaterol, a novel long-acting beta2-agonist, on isolated human bronchi.

Indacaterol is a novel beta2-adrenoceptor agonist in development for the once-daily treatment of asthma and chronic obstructive pulmonary disease. The present study evaluated the relaxant effect of indacaterol on isolated human bronchi obtained from lungs of patients undergoing surgery for lung carcinoma. Potency (-logEC50), maximal relaxant effect (Emax) and onset of action were determined at resting tone. Duration of action was determined against cholinergic neural contraction induced by electrical field stimulation (EFS). At resting tone, -logEC50 and Emax values were 8.82+/-0.41 and 77+/-5% for indacaterol, 9.84+/-0.22 and 94+/-1% for formoterol, 8.36+/-0.16 and 74+/-4% for salmeterol, and 8.43+/-0.22 and 84+/-4% for salbutamol, respectively. In contrast to salmeterol, indacaterol did not antagonise the isoprenaline response. Indacaterol's onset of action (7.8+/-0.7 min) was not significantly different from that of formoterol (5.8+/-0.7 min) or salbutamol (11.0+/-4.0 min), but it was significantly faster than that of salmeterol (19.4+/-4.3 min). EFS-induced contractions were inhibited with -logIC50 values of 6.96+/-0.13 (indacaterol), 8.96+/-0.18 (formoterol), 7.18+/-0.34 (salmeterol) and 6.39+/-0.26 (salbutamol). Duration of action was >12 h for indacaterol and salmeterol, and 35.3+/-8.8 and 14.6+/-3.7 min for formoterol and salbutamol, respectively. In isolated human bronchi, indacaterol behaved as a long-acting beta2-adrenoceptor agonist with high intrinsic efficacy and fast onset of action.

Adrenergic beta-Agonists↗
PubMed2006

Antidepressants: general practitioners' opinions and clinical practice.

OBJECTIVE: To describe and compare general practitioners' (GPs) opinions on antidepressant drugs and their prescriptions to depressed patients. METHOD: Between November 2000 and July 2001 a representative sample of French GPs was asked their opinion of the 15 most prescribed antidepressants, and then to describe the treatments of the current depressive episode of four depressive patients each, their changes and the reasons thereof. RESULTS: One hundred and eighty-one GPs and 778 patients participated. The best-ranked antidepressants by the GPs were paroxetine, fluoxetine, sertraline and clomipramine for efficacy, and paroxetine, tianeptine, sertraline and fluoxetine for tolerability. In patients, the drugs most often prescribed were fluoxetine, paroxetine, and sertraline. Those least often stopped for intolerance were moclobemide (0%), dosulepine (0%), venlafaxine (4.5%) and citalopram (5.0%), and maprotiline (0%), citalopram (1.7%) and venlafaxine (2.3%) for lack of efficacy. The best predictor for prescription of antidepressants was the GPs' overall ranking, itself depending on opinions of the tolerability and efficacy of the drug. However, opinions of tolerability and efficacy were not related to the rates of treatment discontinuation for intolerability or inefficacy. CONCLUSION: Prescriber opinion does not seem related to actual product performance.

Adult↗
PubMed2005

Paradoxal effect of salbutamol in an in vitro model of bronchoprotection.

Salbutamol-induced hyperresponsiveness to acetylcholine was investigated in human and guinea-pig isolated airways and cultured human airway smooth muscle cells. Salbutamol (10(-7)-10(-5) m) inhibited contractions induced by low concentrations of acetylcholine (10(-8)-10(-7) m) but potentiated contractions induced by higher concentrations of acetylcholine (10(-5)-10(-3) m). Pretreatment with the calcium channel antagonist nicardipine suppressed salbutamol-induced hyperresponse. Stimulation of cultured human airway smooth muscle cells with salbutamol (10(-6) m) amplified intracellular calcium concentration rise induced by acetylcholine (10(-5) m). Propranolol (10(-7) m), a beta1- and beta2-adrenoceptor antagonist, and ICI 118551 (10(-7)-10(-6) m), a beta2-adrenoceptor antagonist, suppressed the inhibitory effect of salbutamol but did not inhibit the hyperresponse on high concentrations of acetylcholine. In contrast, higher concentration of propranolol (10(-6) m) inhibited salbutamol-induced hyperreactivity. Effects of salbutamol were not affected by atenolol, a beta1-adrenoceptor blocker. Salbutamol-induced hyperresponsiveness is mediated through a mechanism involving calcium channel activation.

Acetylcholine↗
PubMed2005

Prognostic impact of psychoactive substances use during hospitalization for intentional drug overdose.

OBJECTIVE: To assess whether current use of psychoactive substance(s) is a prognostic factor during hospitalization for intentional drug overdose (IDO). METHOD: Current intoxication with psychoactive substance(s) [cannabis, opiate, buprenorphine, amphetamine/ecstasy, cocaine, lysergic acid diethylamide (LSD)] was identified using toxicological urinalysis in 671 patients with IDO. An IDO was a priori defined as serious if associated with one of the following events: death, hospitalization in intensive care unit longer than 48 h, respiratory support, use of vasopressive drugs, cardiac massage or dialysis. RESULTS: Subjects positive for toxicological assays were twice as likely to present with serious IDO (OR = 1.9, 95% CI: 1.3-2.8, P = 0.001), independently from a large range of confounding factors. The risk of serious IDO was especially marked in subjects using LSD, buprenorphine or opiates. CONCLUSION: Systematic investigation of substance use could be important to adapt medical management of subjects with IDO in general hospital, but also in primary care and psychiatric settings.

Adult↗
PubMed2005

A randomized, double-blind, double-dummy, safety crossover trial comparing cumulative doses up to 96 microg of formoterol delivered via an HFA-134a-propelled pMDI vs. same cumulative doses of formoterol DPI and placebo in asthmatic patients.

BACKGROUND: Formoterol's effects on the cardiovascular system are well known, but whether these effects are altered by the reformulation of inhalers to replace CFC propellants with HFA propellants is not. OBJECTIVES: To evaluate the effect of cumulative doses up to 96 microg of formoterol delivered via an HFA-134a-propelled pMDI, on cardiac safety and the QTc interval, compared the same cumulative doses delivered via a DPI, in adult patients with moderate-to-severe asthma. METHODS: This study was a multicenter, double-blind, double-dummy, placebo-controlled, three-period, crossover trial in which 22 patients with moderate-to-severe asthma received cumulative doses up to 96 microg of formoterol (12 + 12 + 24 + 48 microg) delivered via a pMDI or a dry power inhaler (DPI). Vital signs and fourteen 12-lead ECG measurements were taken at each clinic visit and at 5-10 days after the final drug administration. RESULTS: An increase from baseline in QTc interval was observed with all formoterol treatment arms in a dose-dependent manner. The maximum increases were 56.3, 62.6 and 25.0 ms for the formoterol pMDI, formoterol DPI and placebo treatments, respectively. Heart rate was increased by 10.7, 14.9 and 6.5 bpm in the pMDI, DPI and placebo groups, respectively. Both formoterol treatments were also associated with a decrease in diastolic blood pressure compared with placebo. CONCLUSIONS: With respect to cardiovascular safety parameters, the administration of formoterol via a pMDI device is comparable to its delivery via a DPI.

Adult↗
PubMed2004

Comparison of pharmacokinetics and metabolism of desloratadine, fexofenadine, levocetirizine and mizolastine in humans.

Abstract Absorption, distribution, metabolism and excretion of desloratadine, fexofenadine, levocetirizine, and mizolastine in humans have been compared. The time required to reach peak plasma levels (tmax) is shortest for levocetirizine (0.9 h) and longest for desloratadine (> or =3 h). Steady-state plasma levels are attained after about 6 days for desloratadine, 3 days for fexofenadine, 2-3 days for mizolastine and by the second day for levocetirizine. The apparent volume of distribution is limited for levocetirizine (0.4 L/kg) and mizolastine (1-1.2 L/kg), larger for fexofenadine (5.4-5.8 L/kg) and particularly large for desloratadine (approximately 49 l/kg). Fexofenadine and levocetirizine appear to be very poorly metabolized (approximately 5 and 14% of the total oral dose, respectively). Desloratadine and mizolastine are extensively metabolized. After administration of 14C-levocetirizine to healthy volunteers, 85 and 13% of the radioactivity are recovered in urine and faeces, respectively. In contrast, faeces are the preferential route of excretion for 14C-fexofenadine (80% vs. 11% of the radioactive dose in urine). The corresponding values are 41% (urine) and 47% (faeces) for 14C-desloratadine, 84-95% (faeces) and 8-15% (urine) for 14C-mizolastine. The absolute bioavailability is 50-65% for mizolastine; it is high for levocetirizine as the percentage of the drug eliminated unchanged in the 48 h urine is 77% of the oral dose; the estimation for fexofenadine is at least 33%; no estimation was found for desloratadine. Fexofenadine is a P-glycoprotein (P-gp) substrate and P-gp is certainly involved both in the poor brain penetration by the compound and, at least partially, in a number of observed drug interactions. An interaction of desloratadine with P-gp has been suggested in mice, whereas the information on mizolastine is very poor. The fact that levocetirizine is a substrate of P-gp, although weak in an in vitro model, could contribute to prevent drug penetration into the brain, whereas it is unlikely to be of any clinical relevance for P-gp-mediated drug interactions.

Absorption↗
PubMed2004

[Pharmacokinetics in the elderly].

Physiological changes that occur in the aging process may directly affect drug pharmacokinetics. In the absence of disease or other pathologic conditions, age-related changes in pharmacokinetics principally affect drug absorption, distribution, metabolism or elimination. One factor that does change consistently with age is renal clearance, consequently a common pharmacokinetic change is reduced drug clearance, especially for drugs excreted largely unchanged by the kidneys. Alteration of the pharmacokinetics of drugs in the elderly may necessitate adjustment of dosages to prevent toxicity or inadequate therapy. As a broad generalization, dosage should be reduced in elderly patients, reflecting the general decline in body function with age.

Absorption↗
PubMed2003

High-performance liquid chromatographic method with diode array detection to identify and quantify atypical antipsychotics and haloperidol in plasma after overdose.

For toxicological purposes, an HPLC assay was developed for the simultaneous determination of haloperidol and atypical antipsychotics (risperidone, 9-hydroxyrisperidone, olanzapine, clozapine) in human plasma. After a double-step liquid-liquid extraction, compounds were separated on a C(8) column eluted with a gradient of acetonitrile and phosphate buffer 50 mM pH 3.8. A sequential ultraviolet detection was used (260, 280 and 240 nm). Calibration curves were linear in the range 10-1000 ng/ml. The limits of quantification were 5 ng/ml for all drugs. Average accuracy at four concentrations ranged from 93 to 109%. Both inter- and intra-day variation coefficients were lower than 11% for all drugs. This simple and rapid method (run time<15 min) is currently used for poison management.

Antipsychotic Agents↗
PubMed2003

Accuracy of self-report and toxicological assays to detect substance misuse disorders in parasuicide patients.

OBJECTIVE: To assess the accuracy of self-reported substance use and toxicological assays in subjects admitted for Intentional Drug Overdose (IDO), using as a reference diagnosis of substance use disorder. METHOD: Self-reported substance use was collected and toxicological assays were carried out in urine samples in 507 patients with IDO. A standardized psychiatric evaluation was performed in 100 randomly selected subjects. RESULTS: In routine practice, the emergency department staff did not investigate substance use in nearly one of two patients. Patients' statements and toxicological assays were more specific than sensitive, with lower scores for toxicological assays. Patients' statements made it possible to detect nearly 80% of subjects with substance use disorder. CONCLUSION: Identification of substance use disorder in subjects with IDO has strong clinical consequences regarding treatment and prevention of suicidal behaviour. Thus, emergency department staff should be made aware of the value of more systematically exploring self-reported substance use.

Adolescent↗
PubMed2003

Synthesis and anti-histaminic evaluation of N-phenyl-(alkyl)-5-(dialkylamino)methyl-2-amino-2-oxazolines.

New N-phenyl(alkyl)-5-(dialkylamino)methyl-2-amino-2-oxazolines, 5a-e, have been synthesized from the corresponding 3-phenyl(alkyl)carbamoyl-2-iminooxazolidines 2. A two-stage hydrolysis reaction led finally to the corresponding ring-opened N-phenyl(alkyl)-N'-[1-(3-(dialkylamino)-propan-2-ol)]ureas 4. The oxazoline ring was regenerated through an intramolecular nucleophilic substitution involving an halogen atom introduced by the reaction of thionyl chloride on 4. Pharmacological properties of 5a-e were evaluated on histaminic and adrenergic receptors in guinea-pig trachea and rat aorta. Compounds 5b and 5e showed a selective anti-histaminic effect on guinea-pig airways, but a significant response was obtained for a concentration >10(-6) M. No pharmacological activity was obtained with oxazoline 5c whereas oxazolines 5a and 5d seemed to present a non-selective effect on the contractile mechanism of the smooth muscle cell.

Acetylcholine↗
PubMed2003

Assessment of handling of inhaler devices in real life: an observational study in 3811 patients in primary care.

The correct use of inhalation devices is an inclusion criterion for all studies comparing inhaled treatments. In real life, however, patients may make many errors with their usual inhalation device, which may negate the benefits observed in clinical trials. Our study was undertaken to compare inhalation device handling in real life. A total of 3811 patients treated for at least 1 month with an inhalation device (Aerolizer, Autohaler, Diskus, pressurized metered dose inhaler (pMDI), or Turbuhaler) were included in this observational study performed in primary care in France between February 1st and July 14th, 2002. General practitioners had to assess patient handling of their usual inhaler device with the help of a checklist established for each inhaler model, from the package leaflet. Seventy-six percent of patients made at least one error with pMDI compared to 49-55% with breath-actuated inhalers. Errors compromising treatment efficacy were made by 11-12% of patients treated with Aerolizer, Autohaler, or Diskus compared to 28% and 32% of patients treated with pMDI and Turbuhaler, respectively. Overestimation of good inhalation by general practitioners was maximal for Turbuhaler (24%), and lowest for Autohaler and pMDI (6%). Ninety percent of general practitioners felt that participation in the study would improve error detection. These results suggest that there are differences in the handling of inhaler devices in real life in primary care that are not taken into account in controlled studies. There is a need for continued education of prescribers and users in the proper use of these devices to improve treatment efficacy.

Adult↗
PubMed2002

SR 142801, a tachykinin NK(3) receptor antagonist, prevents beta(2)-adrenoceptor agonist-induced hyperresponsiveness to neurokinin A in guinea-pig isolated trachea.

We investigated whether fenoterol was able to enhance contractile responsiveness to neurokinin A (NKA) on the guinea-pig isolated trachea. We then studied the effects of two inhibitors of nuclear factor kappa B (NFkappaB), gliotoxin and pyrrolidine dithiocarbamate, and of the tachykinin NK(1), NK(2) and NK(3) receptor antagonists, SR 140333, SR 48968 and SR 142801 and determined whether tachykinin receptor gene expression was up-regulated in the trachea after exposure to fenoterol. Fenoterol (0.1 microM, 15 h, 21 degrees C) induced an increased contractile response to NKA (mean of difference in maximal tension between control and fenoterol +/- S.E.M; +0.47 +/- 0.14 g, n = 26, P < 0.01). This hyperresponsiveness was strongly reduced by co-incubation with gliotoxin (0.1 microg/ml) or pyrrolidine dithiocarbamate (0.1 mM) and abolished by SR 140333 (0.1 microM) and SR 142801 (0.1 microM). SR 48968 (0.1 microM) diminished the tracheal contractility to NKA but failed to reduce the hyperreactivity induced by fenoterol. Tachykinin NK(1) receptor (NK(1)R), NK(2) receptor (NK(2)R) and NK(3) receptor (NK(3)R) gene expression was analyzed by semiquantitative RT-PCR. Compared to control tissues, NK(1)R and NK(2)R mRNA expression was increased by about 1.6-fold and 1.4-fold, respectively, in tissues treated with fenoterol. We were unable to detect the presence of NK(3)R mRNA in the guinea-pig trachea. In conclusion, fenoterol induces tracheal hyperresponsiveness to NKA and an up-regulation of NK(1)R and NK(2)R gene expression. The hyperresponsiveness implicates the NFkappaB pathway and is abolished by tachykinin NK(1) (SR 140333) and NK(3) (SR 142801) receptor antagonists.

Acetylcholine↗
PubMed2002

[Pharmacokinetics in the elderly].

Physiological changes that occur in the aging process may directly affect drug pharmacokinetics. In the absence of disease or other pathologic conditions, age-related changes in pharmacokinetics principally affect drug absorption, distribution, metabolism or elimination. One factor that does change consistently with age is renal clearance, consequently a common pharmacokinetic change is reduced drug clearance, especially for drugs excreted largely unchanged by the kidneys. Alteration of the pharmacokinetics of drugs in the elderly may necessitate adjustment of dosages to prevent toxicity or inadequate therapy. As a broad generalization, dosage should be reduced in elderly patients, reflecting the general decline in body function with age.

Absorption↗
PubMed2001

Estradiol decreases the acetylcholine-elicited airway reactivity in ovariectomized rats through an increase in epithelial acetylcholinesterase activity.

Estrogen replacement therapy (ERT) is frequently prescribed for postmenopausal women. Epidemiological data suggest that sex hormones may play a role in the expression of asthma, but the mechanism(s) whereby this influence is mediated remain(s) unclear. To better understand the role of physiologic doses of estrogens in airway function, we tested the hypothesis that 17beta-estradiol (E(2), 10 microg/kg per d for 21 d) given to oophorectomized female rats modifies airway responsiveness to cholinergic agonists, compared with oophorectomized rats given placebo. In vivo, the concentration of inhaled acetylcholine (ACh) required to double pulmonary resistance (EC(200)RL) in anesthetized spontaneously breathing tracheotomized rats was calculated as an index of airway responsiveness. E(2)-treated rats were less responsive to ACh than placebo-treated rats (EC(200)RL, 9.40 +/- 1.48 vs. 1.52 +/- 0.85 mg. ml(-1), respectively). Ex vivo airway responsiveness was evaluated with the cumulative concentration-response curve (CCRC) of isolated tracheal segments. Compared with placebo, E(2) treatment significantly increased the EC(50) of ACh (p = 0.01) but did not alter the CCRC to carbachol. Removing the epithelium or treatment with physostigmine abolished the difference in EC(50) of ACh between the groups. Acetylcholinesterase (AChE) activity of homogenized whole trachea was 1.4-fold greater in the E(2)-treated group compared with placebo (p = 0.02), whereas no difference was found in homogenized epithelium-free trachea. We conclude that E(2) treatment decreases airway responsiveness to ACh in ovariectomized rats at least in part by increasing AChE activity dependent on the presence of the epithelium.

Acetylcholine↗
PubMed2001

Comparison between formoterol 12 microg b.i.d. and on-demand salbutamol in moderate persistent asthma.

Inhalation of on-demand salbutamol (ODS) several times daily is sometimes the only beta2-agonist prescribed in moderate persistent asthma, whereas a long-acting beta2-agonist should be added. This trial aimed to compare the efficacy of formoterol dry-powder capsule 12 microg b.i.d. (Foradil) and ODS in patients with moderate persistent asthma treated with inhaled corticosteroids, in the conditions of real practice. Two hundred and fifty-nine patients were randomized (formoterol; 130; ODS: 129) in this open, parallel-group trial. The mean increases in morning peak expiratory flow (PEF primary variable) and evening PEF over the 3-month treatment period were statistically significantly higher with formoterol: +25.7 and +24.1 l min(-1), respectively vs. +4.5 and +0.5 l min(-1) respectively with ODS. The increase in FEV1 was statistically significantly higher with formoterol at months 1 and 3. Formoterol reduced the use of salbutamol as rescue medication by two-thirds. The percentages of symptom-free days and nights statistically significantly increased with formoterol (+20% and +33% respectively), but did not significantly change with ODS. Clinically relevant and statistically significant improvement in the mean total score of the St George's Hospital Respiratory Questionnaire was observed in the formoterol group. Adverse events were similar in the two groups. The results show that treatment with formoterol has significant advantages over ODS in patients with moderate persistent asthma.

Adrenergic beta-Agonists↗
PubMed2001

Prolonged moderate hyperoxia induces hyperresponsiveness and airway inflammation in newborn rats.

Bronchopulmonary dysplasia is the most common cause of chronic pulmonary disease in premature infants. Airway inflammation appears to play a major pathogenetic role together with barotrauma and oxygen toxicity. The aim of the present study was to determine the effect of a 15-d exposure to moderate hyperoxia (FiO2, 50%) on airway reactivity and inflammatory response in neonatal and adult rats. We studied in isolated tracheal rings the 1) isometric contraction to cumulative concentrations of carbachol (10(-8) to 10(-3) M); 2) epithelial, submucosal, smooth muscle, and connective tissue surface area; and 3) distribution of inflammatory cells (mastocytes, granulocytes, macrophages) by using MAb. Reactivity to carbachol was significantly increased in the hyperoxic pups, in which a 13% increase in tracheal smooth muscle surface area was observed. Type-I mast cells and macrophages (submucosa and connective tissue) and granulocytes (connective tissue) were increased in the neonatal hyperoxic group. Hyperoxia did not influence functional, morphometric, or cellular data in adult rats. In conclusion, exposure of newborn rats to moderate hyperoxia induces airway hyperresponsiveness and histologic changes similar to those reported in bronchopulmonary dysplasia. Hyperresponsiveness may be ascribed to an increase in smooth muscle related to the release of yet undetermined mediators by inflammatory cells infiltrating the airways. Lung immaturity definitely plays a role because similar alterations are not observed in adult rats.

Animals↗
PubMed2001

Synthesis and pharmacological evaluation of 5-dialkylaminomethyl-2-amino-2-oxazolines as H1-antagonists.

New 5-dialkylaminomethyl-2-amino-2-oxazolines have been synthezised in two steps from the corresponding dialkylamines. They were evaluated in-vitro as H1-antagonists. Compounds 1c, 1d and 1j significantly antagonized histamine-induced contraction of guinea-pig trachea with a rightward shift of the concentration-response curve to histamine. Compound 1f, 5-[(4-benzyl-1-piperidinyl)methyl]-2-amino-2-oxazoline, induced an increase in acetylcholine Emax (the maximal response to acetylcholine 10(-3) M) and a shift to the left of the concentration-response curve. The lack of effect of this compound on histamine-induced contraction rules out a non-selective potentiation of the contraction mechanisms. Preliminary structure-activity results were reported partly based on physicochemical results.

Acetylcholine↗