Sex differences in hypokalaemic and electrocardiographic effects of inhaled terbutaline

Abdul R. A. Rahman, Denis G. McDevitt, Allan D. Struthers, Brian J. Lipworth

    Research output: Contribution to journalArticle

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    Abstract

    BACKGROUND: Gender differences in the chronotropic effects of infused isoprenaline have previously been described. The aim of the present study was to investigate possible gender differences in hypokalaemic, chronotropic, and electrocardiographic effects of inhaled terbutaline. METHODS: Twenty healthy volunteers (10 female) were recruited (mean age 24 years for women (F) and 22 years for men (M). Subjects were given either inhaled terbutaline 5 mg or placebo in single blind, randomised crossover fashion and the following measurements were made for four hours after inhalation: (a) serum potassium concentration; (b) heart rate; (c) electrocardiographic sequelae (T wave amplitude, Q-Tc interval). The effects of terbutaline on serum potassium was chosen as the primary end point for detecting a 0.3 mmol/l difference between sexes, with a beta error of 0.2 and alpha set at 0.05. RESULTS: The hypokalaemic effects of terbutaline were significantly greater in women, the potassium results (means and 95% CI) being as follows: lowest potassium concentration--F 3.12 (2.96-3.28) mmol/l v M 3.65 (3.49-3.81) mmol/l; percentage change from baseline at one hour--F 15.4% (11.5-19.3%) v M 8.5% (4.6-12.3%); average potassium concentration during the four hours--F 3.39 (3.33-3.46) mmol/l v M 3.78 (3.72-3.85) mmol/l. There was no significant regression between body weight and the potassium response to terbutaline. There were also significant sex differences for T wave, Q-Tc, and heart rate response. The percentage fall in T wave amplitude 30 minutes after terbutaline was: F 44.6% (32.1-57.0%) v M 22.4% (9.9-34.8%). CONCLUSIONS: Women are more sensitive to the hypokalaemic, chronotropic, and electrocardiographic sequelae of inhaled terbutaline.
    Original languageEnglish
    Pages (from-to)1056-1059
    Number of pages4
    JournalThorax
    Volume47
    Issue number12
    DOIs
    Publication statusPublished - Dec 1992

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    Terbutaline
    Sex Characteristics
    Potassium
    Heart Rate
    Serum
    Isoproterenol
    Inhalation
    Healthy Volunteers
    Placebos
    Body Weight

    Cite this

    @article{bdf121267a614ab1bbe2bbde40f0da8e,
    title = "Sex differences in hypokalaemic and electrocardiographic effects of inhaled terbutaline",
    abstract = "BACKGROUND: Gender differences in the chronotropic effects of infused isoprenaline have previously been described. The aim of the present study was to investigate possible gender differences in hypokalaemic, chronotropic, and electrocardiographic effects of inhaled terbutaline. METHODS: Twenty healthy volunteers (10 female) were recruited (mean age 24 years for women (F) and 22 years for men (M). Subjects were given either inhaled terbutaline 5 mg or placebo in single blind, randomised crossover fashion and the following measurements were made for four hours after inhalation: (a) serum potassium concentration; (b) heart rate; (c) electrocardiographic sequelae (T wave amplitude, Q-Tc interval). The effects of terbutaline on serum potassium was chosen as the primary end point for detecting a 0.3 mmol/l difference between sexes, with a beta error of 0.2 and alpha set at 0.05. RESULTS: The hypokalaemic effects of terbutaline were significantly greater in women, the potassium results (means and 95{\%} CI) being as follows: lowest potassium concentration--F 3.12 (2.96-3.28) mmol/l v M 3.65 (3.49-3.81) mmol/l; percentage change from baseline at one hour--F 15.4{\%} (11.5-19.3{\%}) v M 8.5{\%} (4.6-12.3{\%}); average potassium concentration during the four hours--F 3.39 (3.33-3.46) mmol/l v M 3.78 (3.72-3.85) mmol/l. There was no significant regression between body weight and the potassium response to terbutaline. There were also significant sex differences for T wave, Q-Tc, and heart rate response. The percentage fall in T wave amplitude 30 minutes after terbutaline was: F 44.6{\%} (32.1-57.0{\%}) v M 22.4{\%} (9.9-34.8{\%}). CONCLUSIONS: Women are more sensitive to the hypokalaemic, chronotropic, and electrocardiographic sequelae of inhaled terbutaline.",
    author = "Rahman, {Abdul R. A.} and McDevitt, {Denis G.} and Struthers, {Allan D.} and Lipworth, {Brian J.}",
    year = "1992",
    month = "12",
    doi = "10.1136/thx.47.12.1056",
    language = "English",
    volume = "47",
    pages = "1056--1059",
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    }

    Sex differences in hypokalaemic and electrocardiographic effects of inhaled terbutaline. / Rahman, Abdul R. A.; McDevitt, Denis G.; Struthers, Allan D.; Lipworth, Brian J.

    In: Thorax, Vol. 47, No. 12, 12.1992, p. 1056-1059.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Sex differences in hypokalaemic and electrocardiographic effects of inhaled terbutaline

    AU - Rahman, Abdul R. A.

    AU - McDevitt, Denis G.

    AU - Struthers, Allan D.

    AU - Lipworth, Brian J.

    PY - 1992/12

    Y1 - 1992/12

    N2 - BACKGROUND: Gender differences in the chronotropic effects of infused isoprenaline have previously been described. The aim of the present study was to investigate possible gender differences in hypokalaemic, chronotropic, and electrocardiographic effects of inhaled terbutaline. METHODS: Twenty healthy volunteers (10 female) were recruited (mean age 24 years for women (F) and 22 years for men (M). Subjects were given either inhaled terbutaline 5 mg or placebo in single blind, randomised crossover fashion and the following measurements were made for four hours after inhalation: (a) serum potassium concentration; (b) heart rate; (c) electrocardiographic sequelae (T wave amplitude, Q-Tc interval). The effects of terbutaline on serum potassium was chosen as the primary end point for detecting a 0.3 mmol/l difference between sexes, with a beta error of 0.2 and alpha set at 0.05. RESULTS: The hypokalaemic effects of terbutaline were significantly greater in women, the potassium results (means and 95% CI) being as follows: lowest potassium concentration--F 3.12 (2.96-3.28) mmol/l v M 3.65 (3.49-3.81) mmol/l; percentage change from baseline at one hour--F 15.4% (11.5-19.3%) v M 8.5% (4.6-12.3%); average potassium concentration during the four hours--F 3.39 (3.33-3.46) mmol/l v M 3.78 (3.72-3.85) mmol/l. There was no significant regression between body weight and the potassium response to terbutaline. There were also significant sex differences for T wave, Q-Tc, and heart rate response. The percentage fall in T wave amplitude 30 minutes after terbutaline was: F 44.6% (32.1-57.0%) v M 22.4% (9.9-34.8%). CONCLUSIONS: Women are more sensitive to the hypokalaemic, chronotropic, and electrocardiographic sequelae of inhaled terbutaline.

    AB - BACKGROUND: Gender differences in the chronotropic effects of infused isoprenaline have previously been described. The aim of the present study was to investigate possible gender differences in hypokalaemic, chronotropic, and electrocardiographic effects of inhaled terbutaline. METHODS: Twenty healthy volunteers (10 female) were recruited (mean age 24 years for women (F) and 22 years for men (M). Subjects were given either inhaled terbutaline 5 mg or placebo in single blind, randomised crossover fashion and the following measurements were made for four hours after inhalation: (a) serum potassium concentration; (b) heart rate; (c) electrocardiographic sequelae (T wave amplitude, Q-Tc interval). The effects of terbutaline on serum potassium was chosen as the primary end point for detecting a 0.3 mmol/l difference between sexes, with a beta error of 0.2 and alpha set at 0.05. RESULTS: The hypokalaemic effects of terbutaline were significantly greater in women, the potassium results (means and 95% CI) being as follows: lowest potassium concentration--F 3.12 (2.96-3.28) mmol/l v M 3.65 (3.49-3.81) mmol/l; percentage change from baseline at one hour--F 15.4% (11.5-19.3%) v M 8.5% (4.6-12.3%); average potassium concentration during the four hours--F 3.39 (3.33-3.46) mmol/l v M 3.78 (3.72-3.85) mmol/l. There was no significant regression between body weight and the potassium response to terbutaline. There were also significant sex differences for T wave, Q-Tc, and heart rate response. The percentage fall in T wave amplitude 30 minutes after terbutaline was: F 44.6% (32.1-57.0%) v M 22.4% (9.9-34.8%). CONCLUSIONS: Women are more sensitive to the hypokalaemic, chronotropic, and electrocardiographic sequelae of inhaled terbutaline.

    U2 - 10.1136/thx.47.12.1056

    DO - 10.1136/thx.47.12.1056

    M3 - Article

    C2 - 1494770

    VL - 47

    SP - 1056

    EP - 1059

    JO - Thorax

    JF - Thorax

    SN - 0040-6376

    IS - 12

    ER -