Antagonism of the effects of clonidine by the alpha 2-adrenoceptor antagonist, fluparoxan.
Br J Clin Pharmacol
; 39(5): 477-83, 1995 May.
Article
em En
| MEDLINE
| ID: mdl-7669482
ABSTRACT
1. The effects of fluparoxan, an alpha 2-adrenoceptor antagonist, on the pharmacodynamic changes induced by clonidine were investigated in this placebo-controlled, double-blind, two-period, cross-over study in 16 healthy male volunteers (aged 19 to 44 years). 2. Subjects received either fluparoxan or placebo, twice-daily for 5 1/2 days (11 doses). One hour after the first and last dose of each treatment period, clonidine (200 micrograms) was infused intravenously over 5 min. 3. Indices of clonidine-mediated pharmacodynamic responses (growth hormone secretion, bradycardia, hypotension, xerostomia and sedation) were taken before and after clonidine infusion. Growth hormone secretion was assessed by quantifying serum growth hormone concentrations; sedation was assessed by both visual analogue scales (VAS) and by a visual psychomotor response meter, measuring critical flicker fusion (CFF). 4. The majority of subjects reported minor adverse events such as lethargy, headache and dry mouth following clonidine infusion. All adverse events were likely to be related to clonidine, as they occurred consistently between treatment groups. Fluparoxan has, however, in previous studies been reported to cause headache and light-headedness. 5. Prior to the clonidine infusion, fluparoxan caused small but statistically significant increases in systolic blood pressure (4 mm Hg) and salivary flow (approximately 30%) after both single and repeated doses. A small increase in heart rate (2 beats min-1) was seen after a single dose which was also statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Piperoxano
/
Pirróis
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Pressão Sanguínea
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Clonidina
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Antagonistas Adrenérgicos alfa
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Frequência Cardíaca
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Antidepressivos
Tipo de estudo:
Clinical_trials
Limite:
Adult
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Humans
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Male
Idioma:
En
Revista:
Br J Clin Pharmacol
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
Reino Unido
País de publicação:
ENGLAND
/
ESCOCIA
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GB
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GREAT BRITAIN
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INGLATERRA
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REINO UNIDO
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SCOTLAND
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UK
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UNITED KINGDOM