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Biomedical subjects

N Moore

Publications and source records attributed to N Moore.

At least 217 records · Page 12Linked to original sources
PubMedDate not supplied

Electrophysiological effects of intravenous clonidine on sinus node function and conduction in man.

We studied the electrophysiological effects of clonidine in 10 patients (mean age, 69 years) without sinus dysfunction or atrioventricular block. An endocavitary study was performed with two multipolar catheters, one to record and stimulate the right atrium, the other to record the His bundle potential. The stimulations were delivered by an orthorhythmic stimulator. Clonidine, 150 micrograms, was injected intravenously over 10 min. The usual electrophysiological parameters for studying atrioventricular conduction and sinus function were measured under basal conditions, between the 10th and 25th min, and between the 25th and 40th min following the onset of the injection of clonidine. Sinus cycle length, maximum corrected sinus node recovery time, estimated atrio-sinoatrial conduction time, and premature atrial stimulation-response curve were not influenced by clonidine. There were also no changes in conduction interval, anterograde conduction point, effective refractory period of the atrioventricular node, and intraventricular conduction time. We conclude that intravenous clonidine does not change the electrophysiological parameters in man.

Aged↗
PubMedDate not supplied

[Haemodynamic and metabolic effects of exercise test in diabetic patients with arteritis treated or not with nicergoline (author's transl)].

A randomised crossover study in eleven diabetic patients with arteritis compared the effects of nicergoline (2,5 mg i.v.) or placebo on haemodynamic and metabolic parameters after exercise tests. Haemodynamic modifications after effort following placebo administration were typical: raised systolic blood pressure, and increased heart rate and myocardial oxygen requirements (systolic BP x heart rate). Modifications after similar effort following nicergoline involved an increase in systolic B.P. only, heart rate and myocardial oxygen requirements remaining unchanged. Blood lactic acid levels after effort and treatment were significantly higher (p. less than 0.01) than after effort without treatment. Overall metabolic and haemodynamic results demonstrate an increase in effort tolerance in diabetic patients with arteritis after nicergoline, this having been previously observed in healthy subjects.

Aged↗
PubMedDate not supplied

[Comparative vasodilator action of 5 vasodilators: dihydroergotoxine, nicergoline, papaverine, naftidrofuryl and buflomedil on the femoral artery of the dog].

1. Papaverine (PAP), Naftidrofuryl (NAF), Buflomedil (BUF), Nicergoline (NIC) and Dihydroergotoxine (DIT) were injected in the dog iliac artery at increasing doses (25, 100, 400, 1600 micrograms . kg-1) successively at 10 minutes intervals and the femoral blood flow was measured with an electromagnetic flowmeter. The same volume of saline was injected in the contralateral iliac artery. Heart rate and radial artery pressure were measured and the femoral resistances computed. Noradrenaline (2 microgram . kg-1) was injected before and after the highest dose of vasodilators. 2. The three muscular vasodilators (PAP, BUF, NAF) had an immediate, powerful, dose-dependent but short lasting effect since only after 1600 microgram . kg-1 of PAP, there was still a significant vasodilator effect after the tenth minute. Little or no effect was observed on systemic blood pressure except for the higher doses of these compounds which produced a slight decrease accompanied by a simultaneous tachycardia. 3. The two ergot derivatives NIC and DHT caused a moderate but much longer acting decrease of femoral resistance although 100 micrograms . kg-1 DHT also caused an increase of the femoral resistance. This biphasic effect has been already described on other experimental models. The higher doses of these compounds decreased systemic blood pressure and produced a slight bradycardia as already reported (Boismare and Lefrancois, 1978; Huchet et al., 1981; Moore et al., 1981). The pressor effect of noradrenaline was reversed by NIC and DHT, confirming their alpha adrenoceptor blocking properties.

Animals↗
PubMedDate not supplied

[Hypobaric hypoxia effects on a conditioned avoidance response and on ADP, AMP dopamine and noradrenaline cerebral levels in rats treated or not with naftidrofuryl (author's transl)].

Hypobaric hypoxia (300 mm Hg = 7180 m) was performed during 30 min. for a day during five consecutive days in rats treated or not with naftidrofuryl (15 mg/kg- i.p. daily). A conditioned avoidance response studied on five days shows a reduction of the performances in control rats but not ir treated ones. AMP and ADP cerebral levels were unchanged in the two groups. Hypoxia induced in control rats a reduction of the catecholamine cerebral levels which was not observed in treated rats. In conclusion the protection afforded by naftidrofuryl seems to be due mainly to a reduction of the catecholamine utilization during hypoxia.

Adenosine Diphosphate↗
PubMedDate not supplied

[Evaluation of hospital cost of six days of treatment of deep venous thrombosis. Comparison of subcutaneous nadroparin and intravenous heparin in 40 patients].

For curative treatment of deep vein thrombosis, all trials have shown that twice a day low molecular weight heparin were at least as efficacious as unfractionated heparin on clot reduction or stabilisation. Through the unit cost of low molecular weight heparin is higher, the real cost of treatment should take into account not only the cost of the drug, but also the cost of materials used and lab tests as well as the time necessary. We have therefore prospectively compared the operating and overall costs of nadroparin and intravenous heparin treatment of deep vein thrombosis in hospitalised patients (21 with unfractionated heparin and 19 with nadroparin). The results show that low molecular weight heparin is no more expensive than treatment with unfractionated heparin (336 +/- 74.9 F for unfractionated heparin and 344.9 +/- 44.05 F for nadroparin). In addition, using nadroparin rather than heparin saves approximately one hour per patient per week nursing time (42 +/- 7 minutes vs 104.0 +/- 10.7 minutes, p < 0.05). The methodology of this study should be repeated with other low molecular weight heparin and low molecular weight heparin compare not only to standard i.v. heparin, but also to standard SC heparin.

Adult↗
PubMedDate not supplied

Cefepime pharmacokinetics in cystic fibrosis.

STUDY OBJECTIVE: To determine the disposition of cefepime in patients with cystic fibrosis compared with healthy controls. DESIGN: Open-label, single-dose study. SETTING: Laboratoire de Pharmacocinétique Clinique, Université Laval, Québec, Canada. PATIENTS AND SUBJECTS: Twelve patients with the confirmed diagnosis of cystic fibrosis (CF) and 12 healthy volunteers. One subject with CF withdrew for personal reasons; the data of another patient were excluded from the evaluation of renal values due to incomplete urine collection. INTERVENTIONS: A single 2000-mg dose of cefepime was administered as a 30-minute intravenous infusion. Healthy subjects did not use any other drugs throughout the study. Those with CF refrained from taking prophylactic antibiotics prior to and during the study, but continued to use pancreatic enzymes, multivitamins, and beta-agonist and/or steroid inhalers. One patient continued insulin treatment. MEASUREMENTS AND MAIN RESULTS: Cefepime's maximum concentration was approximately 150 micrograms/ml at the end of the infusion, half-life 2-2.5 hours, and urinary recovery 80% in both groups. No statistically significant difference was seen in any of the pharmacokinetic values between the groups, except for the mean residence time (2.03 +/- 0.26 vs 2.39 +/- 0.37 hrs; p < 0.02). Total clearance was 19% higher in patients with CF than in healthy volunteers (119.7 +/- 20.1 vs 103.5 +/- 19.8 ml/min), perhaps due to higher renal (95.1 +/- 12.4 vs 85.1 +/- 12.0 ml/min) and/or nonrenal (25.4 +/- 13.1 vs 18.4 +/- 12.0 ml/min) clearances in subjects with CF. CONCLUSIONS: The disposition of cefepime is not significantly affected by CF, and dosage adjustment appears not to be necessary in these patients.

Adolescent↗
PubMedDate not supplied

[French pharmacovigilance database system: examples of utilisation].

UNLABELLED: The French drug surveillance (pharmacovigilance) system is based on a network of 31 regional centres which receive adverse drug reaction (ADR) reports from health professionals and are drug information centers. Cases are entered into a common database, with causality scores. This database contains large amounts of data, which may be used for pharmaco-epidemiological studies. As an example, all cases in which an antihypertensive drug, suspect or not, was cited were identified. ACE-inhibitor cough was also explored. RESULTS: Since 1985, > 70,000 case reports have been entered into the database. 63 per cent were reported by specialists, 20 per cent by GPs. 54 per cent came from University Hospitals, 21 per cent from private practice. The most numerous age group was 60 to 69. The overall sex ratio (F/M) was 1.28, the female preponderance being most marked at < 39 and > 70 years of age. 43 per cent took only one drug, 20 per cent two drugs, 13.4 per cent three, and 24 per cent > three drugs. The most frequently reported effects concerned the skin and appendages (15 per cent), general status and central nervous system (9.5 per cent each), platelets, liver, and GI systems (6 per cent each). Outcome was favourable in 74 per cent. Dechallenge was positive in 71 per cent, rechallence in 6 per cent. 3.4 per cent of the patients died; in 2.2 per cent death was related to a reaction. Causality assessment indicated close temporal relationship (C2 or C3) in 69 per cent of cases; in 51 per cent of cases, no other obvious cause was found. 66 per cent of the reactions were labelled when reported. The database could also be used to explore drug utilisation: as an example, we studied the age and sex distribution of reports containing antihypertensive drugs, irrespective of their possible causal role in the reaction. Antihypertensives were mentioned in 14 per cent of the reports. The age distribution was skewed towards greater age, with a maximum of 70 years. F/M was 1.57, with more M use < 20 and 30-59, whereas F were more common between 20-29 and 60 years. beta-blockers were more often associated with patients under 70, whereas above 70 diuretics and centrally acting antihypertensive drugs were more often reported. This could be related to greater use or worse tolerance of these drugs. As an example of the exploration of a specific drug-reaction relationship, we explored the relationship between the use of ACE inhibitors (ACEI) and cough. ACE inhibitors were present in 6 per cent of cases, but in 75 per cent of reports of cough. F/M was 1.29 (NS) for all reports concerning ACEI, 1.28 for cough unrelated to ACEI, 2.1 for cough with ACEI (P < 0.05). Cough was present in 12 per cent of all reports concerning ACEI. There was no clear difference between ACEI for cough or sex ratio; women cough more with ACEI. This does not seem related to greater ACEI use by women or to greater sensitivity of women to cough. The reason for this sex difference remains to be explained. There are large amounts of essentially underutilized data in drug surveillance databases. How they can or should be used remains to be validated.

Adult↗
PubMedDate not supplied

[Focus on the safety of ibuprofen at the analgesic-antipyretic dose].

Ibuprofen is a non-steroidal anti-inflammatory drug, available over the counter in most countries at analysis doses (600-1200 mg/day). After several years of such use, it would seem worthwhile to review recent safety data for this drug compared to reference analgesics. Spontaneous reporting to drug surveillance systems suggests one adverse reaction for every 5 million (UK) to 25 million (USA) 200 mg tablets sold, with one reported fatality for 0.6 to 23 billion tablets sold. During clinical and post-marketing studies, the frequency of adverse events was similar to that found with placebo or paracetamol. In a meta-analysis involving 46000 patients, the incidence of digestive events was 5 per cent, with 0.02 per cent upper GI bleeds. A prospective trial in 84000 children reported 0.007 per cent GI bleeds. Case-control studies of upper GI bleeding found odds ratios of the association with ibuprofen between 1 and 3, lower than those associated with aspirin, even at the low 'cardiovascular' doses. Other risks, such as the risk of renal failure, appear equally low. In the case of voluntary overdose, there appear to be little renal or other risk for ingested quantities below 6 g (30 tablets). Less than 1 per cent of the intoxications are rated as severe, and there have been even fewer fatalities. The favourable safety profile of ibuprofen may be related to short term use of low doses in otherwise healthy young patients, associated to a short product half-life, and may be to specific product properties. The quality of patient information may also be an important safety factor. When the safety of the drug in overdose is considered, substitution of aspirin or paracetamol, by ibuprofen, may actually reduce overall risk for the population.

Analgesics, Non-Narcotic↗