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Beta‐adrenoceptor responses to inhaled salbutamol in the elderly.
Author(s) -
Lipworth BJ,
Tregaskis BF,
McDevitt DG
Publication year - 1989
Publication title -
british journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.216
H-Index - 146
eISSN - 1365-2125
pISSN - 0306-5251
DOI - 10.1111/j.1365-2125.1989.tb03568.x
Subject(s) - salbutamol , propranolol , placebo , heart rate , medicine , confidence interval , anesthesia , endocrinology , asthma , blood pressure , alternative medicine , pathology
The purpose of the present study was to evaluate and compare the responsiveness of beta 2‐adrenoceptors in elderly and young subjects. Seven healthy elderly volunteers (72 +/‐ 3 years) were given cumulative doses of inhaled salbutamol (100 micrograms‐4000 micrograms) or placebo, following pre‐treatment with propranolol 40 mg or placebo. Finger tremor (Tr), plasma potassium (K), and heart rate (HR) were measured at each dose step. There were dose‐dependent increases in Tr (P less than 0.001) and HR (P less than 0.001) and falls in K (P less than 0.001), which were completely attenuated by propranolol (P less than 0.001). Comparison with dose‐response curves in a group of young (Y) subjects (24 +/‐ 3 years) given an identical dose protocol of salbutamol showed no evidence of subsensitivity of beta 2‐adrenoceptor responses in the elderly (E) group (mean and 95% confidence intervals for maximum responses): delta K −0.90 (‐1.1(‐)−0.82) mmol l‐1 Y, −0.82 (‐1.04(‐)‐0.60) mmol l‐1 E, delta Tr 274 (213‐335)% Y, 269 (197‐342)% E, delta HR 25 (21‐28) beats min‐1 Y, 26 (21‐31) beats min‐1 E.