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Biomedical subjects

G Vanden Bussche

Publications and source records attributed to G Vanden Bussche.

At least 19 recordsLinked to original sources
PubMed1991

Levocabastine: an effective topical treatment of allergic rhinoconjunctivitis.

The new H1-receptor antagonist levocabastine is the most potent antihistamine available, as shown in classical animal tests for antihistamine activity. Its effects also are very specific, with doses as high as 40,000 times the effective antihistamine dose not displaying other pharmacological effects. In nasal and ocular provocation tests, levocabastine nasal spray and eye drops protected against allergen-induced nasal and ocular symptoms. Twenty-three clinical trials have been performed with levocabastine nasal spray in 1363 patients with allergic rhinitis. At a dose of two sprays per nostril twice daily (if necessary to be increased up to four times daily), levocabastine was significantly better than placebo and as good as or slightly better than cromoglycate in alleviating nasal symptoms. Good to excellent results were reported in about 60% of patients on levocabastine, compared with 37% with placebo and 47% with cromoglycate. Levocabastine eye drops were studied in 21 clinical trials including 1218 patients with allergic conjunctivitis. One drop per eye twice daily (up to four times daily) provided significantly better symptom control than placebo and similar effects as those observed with cromoglycate. Response rates were 71-80% with levocabastine, 55% with placebo and 76% with cromoglycate. Levocabastine has a fast onset of action, with 94% of patients experiencing symptom relief within 15 min after the first instillation of levocabastine eye drops. Three long-term studies (10-16 weeks' duration) showed absence of tachyphylaxis during prolonged treatment with levocabastine. The incidence of adverse experiences was similar for levocabastine, cromoglycate and placebo, for nasal spray as well as eye drops.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1990

R 75251, a new inhibitor of steroid biosynthesis.

R 75251, a new imidazole derivative, inhibited the conversion of androgens to estrogens, of progestins to androstenedione and testosterone, and of 11-deoxycorticosterone to corticosterone in human placenta microsomes, subcellular fraction of rat testis, bovine adrenocortical mitochondria, in cultured rat granulosa, testicular and adrenal cells, respectively. In vitro, no effect on cholesterol synthesis and cholesterol side-chain cleavage was found at concentrations up to 10 microM. In rat granulosa cells, no effect on progesterone production was detected. In vitro, no effect on steroid radioligand binding was observed. In male volunteers, a single dose of 300 mg of R 75251 significantly lowered plasma testosterone and estradiol for 24 hours and increased plasma concentration of 17 alpha-hydroxyprogesterone and progesterone. As compared with ketoconazole high dose (600 mg b.i.d), R 75251 (300 mg b.i.d) was at least as efficacious as inhibitor of testosterone synthesis when studied during ACTH stimulation. In contrast to ketoconazole, R 75251 did not significantly affect circulating adrenal androgen levels in male volunteers. Precursors of gluco- and mineralocorticoids such as 11-deoxycortisol and 11-deoxycorticosterone accumulated more than after ketoconazole administration. The data show that the cytochrome P450-dependent aromatase, 17-hydroxylase/17,20-lyase, and 11-hydroxylase are the target enzymes for R 75251.

Adrenocorticotropic Hormone↗
PubMed1990

Pilot clinical investigation of risperidone in the treatment of psychotic patients.

Sixty-one adult psychotic patients were treated for four weeks in an open dose-finding study with the new combined serotonin-dopamine antagonist risperidone (R 64 766). Risperidone had a rapid onset of action; a highly significant decrease in the total score on the Brief Psychiatric Rating Scale (BPRS) was already noticed after the first week of treatment. There was also a significant decrease in score for individual BPRS items related to positive, negative, and affective symptoms. In spite of the withdrawal of antiparkinson medication at selection, a significant decrease in extra-pyramidal symptoms (EPS) was observed, as assessed on the Simpson and Angus Scale. The Clinical Global Impression of therapeutic effect was consistent with the BPRS scores, showing a constant improvement throughout the study. The mean daily dose of risperidone at the end of the study was 3.7 mg. Tolerance was excellent and only mild side-effects were reported. Vital signs, ECG-parameters, and laboratory values remained within normal limits. This study demonstrates that risperidone has great potential as an effective and well-tolerated alternative for the treatment of chronically psychotic patients. It has potent antipsychotic effects, a low EPS-inducing profile, and, at the same time, it improves the negative and affective symptoms of schizophrenia.

Adolescent↗
PubMed1989

Suppression of colds in human volunteers challenged with rhinovirus by a new synthetic drug (R61837).

This report describes double-blind placebo-controlled trials of a new synthetic antirhinovirus drug, R61837, which showed it to be effective in suppressing colds in human volunteers challenged with rhinovirus type 9. In one trial, R61837 was given by intranasal spray six times a day, commencing 28 h before virus challenge; treatment continued for 4 days and one dose (total dose, 25 mg). This regimen suppressed symptoms until 48 h after medication ceased, at which time colds developed. In another trial, medication with R61837 commenced at 4 h before virus challenge and continued for a total of 6 days (total dose, 36 mg). The drug produced substantial reductions in both the mean daily clinical score and the mean daily nasal secretion weight compared with patients given the placebo. These differences reached statistical significance for 2 and 4 days, respectively. In a further trial, intranasal R61837 was not effective in treating colds even when given shortly after the onset of symptoms and in doses of up to 15 mg/day.

Administration, Intranasal↗
PubMed1988

Alfentanil pharmacokinetics and metabolism in humans.

The metabolism of alfentanil was studied in three healthy subjects after a 1-h infusion of 2.5 mg alfentanil-3H. One of the subjects was a poor hydroxylator of debrisoquine. Pharmacokinetic parameters were similar in the three subjects and were in the same range as those reported for volunteers. The majority of the administered radioactivity was excreted in the urine (90% of the dose), but unchanged alfentanil represented only 0.16-0.47% of the dose. Alfentanil and metabolites were characterized by HPLC co-chromatography with reference compounds and/or by mass spectrometry and quantified by GLC and radio-HPLC. The main metabolic pathway was N-dealkylation at the piperidine nitrogen, with formation of noralfentanil (30% of the dose). Other Phase I pathways were aromatic hydroxylation, N-dealkylation of the piperidine ring from the phenylpropanamide nitrogen, O-demethylation, and amide hydrolysis followed by N-acetylation. Glucuronic acid conjugation of aromatic or aliphatic hydroxyl functions was the main Phase II pathway. The second major metabolite was the glucuronide of N-(4-hydroxyphenyl) propanamide (14% of the dose). The metabolite pattern in these subjects was qualitatively very similar to that described previously in rats and dogs. Differences in the mass balance of urinary metabolites between the three subjects were very small, and there was no qualitative or quantitative evidence for a deficiency in the metabolism of alfentanil in the subject who was a poor metabolizer of debrisoquine.

Alfentanil↗
PubMed1988

Intranasal sufentanil for pre-operative sedation.

Sufentanil, a short-acting and potent narcotic agent, was studied as a premedicant administered by the nasal route. A total dose of 5 micrograms appeared to be too low, while either 10 or 20 micrograms was very effective in producing sedation. Side effects were minor. There appeared to be no differences between nose drops and spray. In a further study, sufentanil nose drops were compared with saline 0.9% in a double-blind fashion. Sedation of rapid onset but of limited duration was observed in the majority of patients who received sufentanil.

Administration, Intranasal↗
PubMed1987

ECG studies with astemizole.

1 Six healthy volunteers took part in a 2-week haemodynamic safety study of astemizole. 2 They were given 30 mg daily (3 X 10 mg tablets) for the first 3 days and 10 mg daily for the next 12 consecutive days. 3 Heart rate, blood pressure, ECG and systolic time intervals at rest were measured before the start and five times during the day. 4 No changes were observed in any of the parameters measured. The configuration of the ECG was not influenced. 5 Serum concentrations of astemizole plus hydroxylated metabolites measured at the end of the study were 16 times lower than those detected in a patient overdosing on 200 mg astemizole.

Adult↗
PubMed1987

Clinical profile of astemizole. A survey of 50 double-blind trials.

From clinical-pharmacologic and clinical data involving over 2,800 patients, astemizole appears to be a very effective and well-tolerated antihistamine. It is superior to placebo and commonly used antihistamines for the relief of rhinitis, particularly rhinorrhea and sneezing. It has a pronounced effect on ocular itching and lacrimation in conjunctivitis and on pruritus and wheals in urticaria. This superiority is due to a very specific, almost complete and sustained histamine H1-blockade. The clinical data confirm the experimental data in relation to its lack of sedative effects.

Astemizole↗
PubMed1987

The pharmacokinetic basis of alfentanil infusion.

Owing to the rapid blood:brain equilibration and the short duration of action, alfentanil is well suited for use in infusion techniques. A pharmacokinetic basis is given for alfentanil infusion schemes in patients undergoing routine surgery. Practical schemes can be worked out according to the general principle of a loading dose followed by a maintenance infusion. The loading dose of 100 micrograms kg-1 may be given as a short infusion, as two incremental doses, or as a combination of a single dose and short infusion. The maintenance infusion rate of approximately 1 microgram kg-1 min-1 results in steady-state plasma levels in the therapeutic range in most patients. Application of small extra doses, in addition to the maintenance infusion and modification of the infusion rate, might result in an appropriate and safe anaesthetic technique in most patients and surgical situations.

Alfentanil↗
PubMed1987

Practical aspects of alfentanil infusion.

The administration of alfentanil by infusion appears to present advantages for the induction and maintenance of anaesthesia during general surgery lasting over 1 h. The following dosage scheme is proposed: a loading dose of 100 micrograms kg-1, given either in one or two doses, or as a fast infusion administered over 10 min, followed by a maintenance infusion at a rate of 1 microgram kg-1 min-1. During maintenance anaesthesia, the infusion rate should be the lowest possible compatible with adequate analgesic effect, and should be further decreased 15-20 min before the projected end of surgery. Fine control of the opioid effect can be achieved with small increments of 7-15 micrograms kg-1 or by alterations of the alfentanil infusion rate. Breathing should be carefully monitored during the post-operative phase. Dedicated syringe pumps have been designed to avoid laborious calculations of the infusion rates and allow simple, rapid changes of the infusion rate.

Alfentanil↗
PubMed1986

Plasma concentrations of astemizole in patients with terminal renal insufficiency, before, during and after hemodialysis.

Four patients undergoing hemodialysis because of terminal renal insufficiency have taken 10 mg of astemizole on two consecutive days. The elimination was followed for 7 days and was found not to be delayed. During dialysis no decrease of the plasma levels of astemizole and its hydroxylated metabolites were observed. On the contrary, a small nonsignificant increase was found which can be explained by the thickening of the blood after ultrafiltration. It can be concluded that astemizole cannot be eliminated by dialysis because of its high protein binding capacity.

Adult↗
PubMed1986

Potential of interaction between the H1-antagonist astemizole and other drugs.

Astemizole is a potent H1-antagonist devoid of sedative effects, which was found at single oral daily doses to be very effective in the treatment of allergic rhinitis, allergic conjunctivitis, and urticaria. Its interaction potential on other drugs was studied in various ways. Studies on salivary antipyrine clearance, the 6-beta-hydrocortisol excretion, the elimination rate of ethanol and the indocyanine-green clearance are presented. No changes were observed. Astemizole also was given in combination with diazepam or alcohol. Psychomotor performance failed to show any effects. In none of these studies was there any evidence of interaction of astemizole on other drugs. This review summarizes the data available thus far.

Animals↗
PubMed1985

Epidural sufentanil for postoperative pain relief.

An open pilot study was undertaken to evaluate the analgesic properties of epidurally administered sufentanil in the early postoperative period. After orthopaedic surgery of the lower extremity, four different groups of five adult patients each received either 15 micrograms (group 1), 30 micrograms (group 2), 50 micrograms (group 3) or 75 micrograms (group 4) sufentanil via an epidural catheter previously used for the surgical procedure. Results were satisfactory in groups 3 and 4 with very good relief of pain and a mean duration of action of 372 and 307 minutes respectively. Dosage above 50 micrograms did not seem to improve the quality or duration of pain relief, although the onset of action was faster with 75 micrograms. Sedation was always present in patients with effective analgesia. In the present study respiratory depression was not evident, but three patients complained of itching and two of urinary retention.

Adolescent↗
PubMed1985

[Total review of all results collected worldwide with astemizole (Hismanal)].

From the start of the Astemizole clinical investigations, until now the results of 39 trials including more than 2300 patients are available. These results show that Astemizole is an effective and safe Histamine-H1-antagonist for the therapy of hayfever, chronic allergic rhinitis, allergic conjunctivitis, chronic urticaria and allergic bronchitis in adults and children. Astemizole was superior to placebo and the classical antihistamines like Clemastine, Terfenadine, Ketotifen, Mequitazine, pheniramine and Chlorphenamine.

Astemizole↗
PubMed1980

Double-blind placebo-controlled studies with flunarizine in venous insufficiency.

In 4 placebo-controlled double-blind studies of patients suffering from venous insufficiency--defined as the presence of varicose veins combined with a range of subjective symptoms and presence of venous ulcers--flunarizine was statistically significantly superior to placebo in improving symptomatology, reducing the circumference of swollen lower legs and ankles, and increasing the speed of healing of venous ulcers. No side-effects were noted.

Cinnarizine↗