Systemic effects of salbutamol and salmeterol in patients with asthma.

BACKGROUND: Knowing the extent of the systemic effects of a new beta 2 agonist relative to an established drug is important for the prediction and interpretation of side effects. A recent study in which the effect of cumulative doses of salbutamol was compared with single doses of salmetreol suggest...

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Main Authors: Bennett, J, Smyth, E, Pavord, I, Wilding, P, Tattersfield, A
Format: Journal article
Language:English
Published: BMJ Publishing Group 1994
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author Bennett, J
Smyth, E
Pavord, I
Wilding, P
Tattersfield, A
author_facet Bennett, J
Smyth, E
Pavord, I
Wilding, P
Tattersfield, A
author_sort Bennett, J
collection OXFORD
description BACKGROUND: Knowing the extent of the systemic effects of a new beta 2 agonist relative to an established drug is important for the prediction and interpretation of side effects. A recent study in which the effect of cumulative doses of salbutamol was compared with single doses of salmetreol suggested that, weight for weight, salmeterol may be up to 10 times more potent than salbutamol. This current study was designed to investigate further the dose equivalence of salmeterol and salbutamol. METHODS: Twelve patients with mild asthma inhaled cumulative doses of placebo, salmeterol 25, 50, 100, and 200 micrograms, and salbutamol 100, 500, 1000, and 1000 micrograms on separate days at hourly intervals in a randomised double blind crossover study. Changes in forced expiratory volume in one second (FEV1), heart rate, plasma potassium concentration, systolic and diastolic blood pressure were measured. Dose equivalence was determined as the dose ratio of salmeterol to salbutamol for the 50% maximum response to salbutamol. RESULTS: No important changes occurred in any measurements following placebo. Salmeterol and salbutamol caused a near maximum increase in FEV1 following the first dose so the dose equivalence for the airway effects could not be estimated. Heart rate increased and plasma potassium concentration and diastolic blood pressure decreased in a dose dependent manner following salmeterol and salbutamol, with median dose equivalences for salmeterol compared with salbutamol of 17.7, 7.8, and 7.6, respectively. CONCLUSIONS: These results confirm that the systemic activity of salmeterol compared with salbutamol is higher than would be expected from in vitro data, particularly for heart rate. Whether this is because of the relatively high dose of salmeterol used or pharmacokinetic differences between the two drugs is uncertain.
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spelling oxford-uuid:a68dafea-54ef-4ec9-adf9-be0cf34ba5ce2022-03-27T02:48:06ZSystemic effects of salbutamol and salmeterol in patients with asthma.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:a68dafea-54ef-4ec9-adf9-be0cf34ba5ceEnglishSymplectic Elements at OxfordBMJ Publishing Group1994Bennett, JSmyth, EPavord, IWilding, PTattersfield, ABACKGROUND: Knowing the extent of the systemic effects of a new beta 2 agonist relative to an established drug is important for the prediction and interpretation of side effects. A recent study in which the effect of cumulative doses of salbutamol was compared with single doses of salmetreol suggested that, weight for weight, salmeterol may be up to 10 times more potent than salbutamol. This current study was designed to investigate further the dose equivalence of salmeterol and salbutamol. METHODS: Twelve patients with mild asthma inhaled cumulative doses of placebo, salmeterol 25, 50, 100, and 200 micrograms, and salbutamol 100, 500, 1000, and 1000 micrograms on separate days at hourly intervals in a randomised double blind crossover study. Changes in forced expiratory volume in one second (FEV1), heart rate, plasma potassium concentration, systolic and diastolic blood pressure were measured. Dose equivalence was determined as the dose ratio of salmeterol to salbutamol for the 50% maximum response to salbutamol. RESULTS: No important changes occurred in any measurements following placebo. Salmeterol and salbutamol caused a near maximum increase in FEV1 following the first dose so the dose equivalence for the airway effects could not be estimated. Heart rate increased and plasma potassium concentration and diastolic blood pressure decreased in a dose dependent manner following salmeterol and salbutamol, with median dose equivalences for salmeterol compared with salbutamol of 17.7, 7.8, and 7.6, respectively. CONCLUSIONS: These results confirm that the systemic activity of salmeterol compared with salbutamol is higher than would be expected from in vitro data, particularly for heart rate. Whether this is because of the relatively high dose of salmeterol used or pharmacokinetic differences between the two drugs is uncertain.
spellingShingle Bennett, J
Smyth, E
Pavord, I
Wilding, P
Tattersfield, A
Systemic effects of salbutamol and salmeterol in patients with asthma.
title Systemic effects of salbutamol and salmeterol in patients with asthma.
title_full Systemic effects of salbutamol and salmeterol in patients with asthma.
title_fullStr Systemic effects of salbutamol and salmeterol in patients with asthma.
title_full_unstemmed Systemic effects of salbutamol and salmeterol in patients with asthma.
title_short Systemic effects of salbutamol and salmeterol in patients with asthma.
title_sort systemic effects of salbutamol and salmeterol in patients with asthma
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AT wildingp systemiceffectsofsalbutamolandsalmeterolinpatientswithasthma
AT tattersfielda systemiceffectsofsalbutamolandsalmeterolinpatientswithasthma