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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 46 (1994), S. 23-28 
    ISSN: 1432-1041
    Keywords: Atenolol ; Captopril ; Central effects ; short term administration ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract The central effects of atenolol (50 mg tds) and captopril (50 mg tds) ingested for a period of seven days were studied in ten healthy volunteers. A placebo and two active control drugs, methyldopa (250 mg tds) and oxazepam (10 mg), were included in the design. Oxazepam was ingested on the seventh day only, with a placebo being taken on the preceding six days. On the seventh day, central effects of the drugs were tested at 10.00–11.00 h (session 1), immediately before the subjects' last dose of each drug and at 2.5–3.5 h after the final dose of each drug (1330–1430 h, session 2). Performance was assessed using digit symbol substitution, continuous attention, letter cancellation, choice reaction time, finger tapping, immediate and short-term memory, critical flicker fusion and two flash fusion. Subjects assessed their mood and well-being on a series of 12 visual analogue scales. Recordings of the EEG and body sway were carried out. Neither atenolol nor captopril altered performance at any of the skills tested. There were no effects on subjectively assessed alertness or mood with captopril, while atenolol significantly increased wakefulness in session 2 and when the two sessions were meaned. Similarly, captopril did not modify body sway, while with atenolol there was a significant decrease in activity in the frequency range 1.0–2.75 Hz from session 1 to session 2. Both captopril and atenolol modified the electrical activity of the brain, with captopril increasing delta and theta activity and atenolol reducing delta, alpha and beta activity. Methyldopa significantly increased the number of involuntary rest pauses in the finger tapping task, and the choice reaction time from session 1 to session 2. There was a decrease in passivity during the first session and an increase in wakefulness in session 2 with methyldopa. This drug also decreased body sway in the frequency range 1.0–2.75 Hz activity in session 2, while oxazepam decreased bodys was at 1.0 to 2.75 Hz and increased activity at 2.5–3.0 Hz in session 2. Oxazepam reduced delta, theta and alpha content of the EEG. The present study has been unable to demonstrate any development of adverse central effects with captopril over a period of 7 days of drug ingestion. With atenolol adverse effects were present following short term dosing but were not more pronounced than with acute ingestion seen in previous studies. However effects on the electrical activity of the brain with atenolol remained after 7 days suggesting that the changes reported previously with single ingestions do not disappear.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 40 (1991), S. 135-139 
    ISSN: 1432-1041
    Keywords: Atenolol ; bisoprolol ; β-adrenoceptor ; cardioselectivity ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A dose-ranging study was performed to compare the β1-adrenoceptor selectivity of bisoprolol with that of atenolol and nadolol. Seven normal subjects (mean age 26 y) were given single oral doses of bisoprolol 5 mg (B5), 10 mg (B10), 20 mg (B20); atenolol 50 mg (A50), 100 mg (A100); nadolol 40 mg (N40); and placebo (PL), in a single blind randomised cross-over design. β2-adrenoceptor responses were assessed by attenuation of finger tremor and cardiovascular responses to graded isoprenaline infusions. Dose-response curves were constructed, and doses of isoprenaline required to increase finger tremor by 100% (IT100), heart rate by 25 beats/min (IH25), SBP by 25 mm Hg (IS25), cardiac output by 35% (IC35), and decrease DBP by 10 mm Hg (ID10), after each treatment were calculated. These indices were compared with placebo response and expressed as dose-ratios. Exercise heart rate (EHR) was used to assess β1-adrenoceptor blockade. There were dose-related increases in plasma concentrations of bisoprolol and atenolol. Reduction of EHR was significantly less with B5 (16.8%) in comparison with all other treatments: B10 21.9%, B20 23.1%; A50 22.5%, A100 22.6%; N40 22.9%. There were small but significant reductions in isoprenaline-induced tachycardia with bisoprolol and atenolol, although mean dose-ratios were considerably less in comparison with N40 (IH25 dose-ratios): B5 2.55, B10 3.18, B20 3.93, A50 2.91, A100 4.89, N40 17.23. There were similar patterns for the other isoprenaline responses. These results show that conventional doses of bisoprolol (10 mg) and atenolol (50 mg) produced equal antagonism of β1 and β2-adrenoceptors, and therefore possess equal degrees of β1-adrenoceptor selectivity. Increasing doses of bisoprolol and atenolol were associated with partial loss of selective β1-adrenoceptor blockade, although antagonism of β2-adrenoceptors was significantly less compared with the effects of nadolol.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 45 (1993), S. 539-543 
    ISSN: 1432-1041
    Keywords: Atenolol ; Bendrofluazide ; Psychomotor performance ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Twelve normal male subjects received single oral doses of atenolol 100 mg (AT), bendrofluazide 5 mg (BFZ), combined atenolol 100 mg and bendrofluazide 5 mg (AT/BFZ), diazepam 5 mg (Dz), or one of two matching placebos, on each of 6 study days. Tests of psychomotor performance [digit symbol substitution (DSST), letter cancellation (LCT), continuous attention, choice reaction time (CRT), finger tapping, short-term memory, body sway], physiological measurements [critical flicker fusion (CFF), two-flash fusion (2FF)] and subjective assessments using visual analogue scales (VAS), were performed at 2 and 4 hours post-ingestion. Dz (active control) significantly worsened VAS scores at 2 h (+0.68) and reduced DSST scores at both 2 h (−15.0) and 4 h (−11.0). AT and BFZ given alone, each produced significant worsening of VAS at 2 h [AT +1.0; BFZ +1.38], but had no significant effects on performance. In combination however, AT/BFZ at 4 h produced significant impairment of DSST scores (−10.4), reduced finger tapping (−16.5) and increased involuntary rest pauses (+16.5). Despite these effects, no change in VAS scores occurred. In summary, we have demonstrated significant impairment of psychomotor performance in normal subjects with the AT/BFZ combination, which was not evident with the single agents and which occurred in the absence of a change in subjective awareness. These central effects may have important clinical implications for patients taking combined antihypertensive medication.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-1041
    Keywords: salbutamol ; asthma ; beta-adrenoceptor ; controlled release formulation ; adverse effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The purpose of the present study was to compare the efficacy and systemic effects of 4 mg and 8 mg doses of salbutamol controlled release (SCR) after single dosing and at steady state in patients with asthma. Fifteen asthmatic patients (Age 36 y, FEV1 85% predicted) were given SCR 4 mg and 8 mg twice daily for 7 days in a randomised double-blind cross-over design, with at least 7 days washout between treatments. There were no differences between the bronchodilator effects of 4 mg and 8 mg doses. There was no evidence of tolerance to the bronchodilator effects after chronic dosing. Morning and evening PEFR measurements also showed improvements during treatment with SCR 4 mg and SCR 8 mg, although there were no differences between the two formulations. Both doses of SCR caused significant objective tremor responses which were maintained after chronic dosing. The 8 mg dose produced a larger tremor response after single dosing, but not at steady-state. Subjective tremor occurred in 7 patients with SCR 8 mg, and in 2 patients with SCR 4 mg. There were no cardiac arrhythmias on Holter ECG monitoring. These results suggest that the 8 mg dose of SCR was no more effective than the 4 mg formulation, and was associated with more systemic adverse effects.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-1041
    Keywords: salbutamol ; sublingual ; oral ; inhaled ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Administration of drugs by the sublingual route provides rapid systemic absorption and avoids first-pass metabolism. The purpose of the present study was to assess the pharmacokinetics, efficacy and adverse effects of standard salbutamol tablets given by this route to patients with asthma. Seven asthmatic patients were given either sublingual salbutamol tablet 2 mg (SL), swallowed tablet 2 mg (O), metered dose inhaler 200 µg (MDI) or placebo (PL), in a randomized single-blind cross-over design. Airways responses (FEV1, FVC, PEFR), finger tremor (Tr), heart rate (HR), plasma potassium (K) and plasma salbutamol were measured over a 6 h period following drug administration. There were highly significant changes in FEV1 with MDI, O and SL routes compared with PL, although the response to MDI was greater and more rapid than with O or SL. There were similar findings for FVC and PEFR responses. There were no adverse effects with MDI, whereas both 0 and SL produced significant tremor responses. There were no differences between O and SL for any of the pharmacodynamic parameters. In addition, pharmacokinetic profiles for O and SL were also similar apart from an initial delay in absorption with SL. There were however, no significant differences in any of the pharmacokinetic parameters, between O and SL. This suggests that buccal absorption of salbutamol was negligible, and that systemic absorption occurred after swallowing of the dissolved sublingual tablet. These results show that sublingual administration of salbutamol tablet has no clinical benefit over the oral route.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 37 (1989), S. 297-300 
    ISSN: 1432-1041
    Keywords: atenolol ; salbutamol ; beta-adrenoceptor antagonists ; cardioselectivity ; metabolic response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The aim of the present study was to evaluate whether metabolic responses to inhaled salbutamol may be used to measure the cardioselectivity of beta-adrenoceptor antagonists. We therefore studied the effects of oral doses of atenolol 50 mg, 100 mg, 200 mg (A50, A100, A200), propranolol 40 mg (P40), and placebo (Pl) on the hypokalaemic (K) and hyperglycaemic (Glu) responses to inhaled salbutamol in five healthy subjects. Increasing doses of atenolol were associated with a progressive attenuation of ΔK compared with placebo: −0.72 mmol·l−1 (Pl) vs −0.20 mmol·l−1 (A200). However, ΔK with A200 was significantly different from the response with P40: +0.12 mmol·l−1. There were partial reductions in the hyperglycaemic response with the beta-adrenoceptor antagonists, although this was only significant (compared with Pl) for P40: ΔGlu 1.92 mmol·l−1 (Pl) vs 0.76 mmol·l−1 (P40). These results show that beta2-adrenoceptor blockade by atenolol is a dose-dependent phenomenon, which may be measured by the attenuation of salbutamol-induced hypokalaemia. However, beta2-adrenoceptor blockade by atenolol 200 mg was less than that by propranolol 40 mg. The glucose response to salbutamol was only partially blocked by propranolol and may therefore not be suitable to assess beta2-adrenoceptor antagonism.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 36 (1989), S. 239-245 
    ISSN: 1432-1041
    Keywords: beta-adrenoceptor ; salbutamol ; airways response ; tremor ; haemodynamic response ; metabolic response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The aim of the present study was to quantify and compare the airways and systemic beta-adrenoceptor responses to inhaled salbutamol in normal subjects. Seven non-atopic, normal subjects were given cumulative doubling doses of inhaled salbutamol (100 µg to 4000 µg) or placebo in a single-blind cross-over design. Airways (sGaw, FEF 50%, FEF 25%), tremor, haemodynamic and metabolic responses were measured at each dose increment. There were dose-related changes in sGaw, FEF 50% and FEF 25% up to a plateau at 1.0 mg. Analysis of individual responses showed that most subjects required either 1.0 or 2.0 mg for maximum bronchodilatation, independent of the parameter of airflow. There was no correlation between maximum response and baseline airway calibre. In contrast to airways effects, systemic beta-adrenoceptor responses did not occur until 500 µg, and a ceiling in the dose-response curve was not reached. Therer were significant correlations between air-ways, tremor and haemodynamic responses, and between different metabolic variables. The intraindividual variability was greatest for tremor and sGaw, although this was small in comparison to the size of maximum change with salbutamol. The converse applied to the hypomagnesaemic response.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 36 (1989), S. 357-360 
    ISSN: 1432-1041
    Keywords: salbutamol ; asthma ; metabolism ; potassium ; glucose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary We have studied the biochemical effects of high doses of inhaled salbutamol in 14 asthmatic patients age 38 years, FEV1 62%. Cumulative doubling doses of inhaled salbutamol were given every 20 min as follows: 100 µg, 200 µg, 500 µg, 1000 µg, 2000 µg, 4000 µg. Plasma glucose, potassium, and magnesium were measured at each step of the doseresponse curve. Salbutamol produced significant hypokalaemic and hyperglycaemic effects, but no significant change in magnesium. There were linear log-dose responses for both glucose (r/it=0.58) and potassium (r=−0.46). There were wide individual variations in maximum responses to salbutamol 4000 µg (as means and 95% confidence intervals): Δ glucose 1.46 (0.83 to 2.09) mmol/l, Δ potassium −0.38 (−0.64 to −0.12) mmol/l. Thus, hypokalaemic and hyperglycaemic effects may occur with doses of salbutamol similar to those curently used for nebulizer therapy (2.5–5 mg). We postulate that during acute exacerbations of airflow obstruction these changes may be accentuated and become clinically relevant.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-1041
    Keywords: salbutamol ; asthma ; controlled-release formulation ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Fifteen patients with asthma were given salbutamol controlled-release (SCR) 4 mg or 8 mg twice daily for seven days, in a randomised double-blind cross-over design. Plasma salbutamol levels were measured after the first and fifteenth doses for a 12 h period following drug ingestion. At steady-state the geometric mean values for Cmax were 8.2 ng/ml for 4 mg, and 16.1 ng/ml for 8 mg. Median tmax values were 300 and 240 min respectively. The geometric mean AUC (0–12) were 4507 ng·min·ml−1 and 8980 ng·min/ml. Peak to trough fluctuation ratios were 0.577 and 0.572. There were no significant differences between 4 mg or 8 mg formulations, for any of the parameters measured, after appropriate corrections for dose. The concentration-time profiles at steady-state showed little fluctuation in plasma salbutamol levels over the twelve hour dosing interval. These results show that 4 mg and 8 mg formulations of SCR provide smooth plasma profiles at steady-state with a twice daily dosing regime.
    Type of Medium: Electronic Resource
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