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.
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- Bennett P., McKinney L., Begenisich T., Kass R. S. Adrenergic modulation of the delayed rectifier potassium channel in calf cardiac Purkinje fibers. Biophys J. 1986 Apr;49(4):839–848. doi: 10.1016/S0006-3495(86)83713-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Burney P. G. Asthma mortality in England and Wales: evidence for a further increase, 1974-84. Lancet. 1986 Aug 9;2(8502):323–326. doi: 10.1016/s0140-6736(86)90012-7. [DOI] [PubMed] [Google Scholar]
- Crane J., Pearce N., Flatt A., Burgess C., Jackson R., Kwong T., Ball M., Beasley R. Prescribed fenoterol and death from asthma in New Zealand, 1981-83: case-control study. Lancet. 1989 Apr 29;1(8644):917–922. doi: 10.1016/s0140-6736(89)92505-1. [DOI] [PubMed] [Google Scholar]
- Ebden P., Farrow P. R., Shaw D., Cookson J. B. 75 deaths in asthmatics prescribed home nebulizers. Br Med J (Clin Res Ed) 1987 Apr 11;294(6577):972–972. doi: 10.1136/bmj.294.6577.972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Grainger J., Woodman K., Pearce N., Crane J., Burgess C., Keane A., Beasley R. Prescribed fenoterol and death from asthma in New Zealand, 1981-7: a further case-control study. Thorax. 1991 Feb;46(2):105–111. doi: 10.1136/thx.46.2.105. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Higgins R. M., Cookson W. O., Lane D. J., John S. M., McCarthy G. L., McCarthy S. T. Cardiac arrhythmias caused by nebulised beta-agonist therapy. Lancet. 1987 Oct 10;2(8563):863–864. doi: 10.1016/s0140-6736(87)91057-9. [DOI] [PubMed] [Google Scholar]
- Johansson S. R., Hjalmarson A. Age and sex differences in cardiovascular reactivity to adrenergic agonists, mental stress and isometric exercise in normal subjects. Scand J Clin Lab Invest. 1988 Apr;48(2):183–191. doi: 10.3109/00365518809085411. [DOI] [PubMed] [Google Scholar]
- Lipworth B. J., McDevitt D. G. Inhaled beta 2-adrenoceptor agonists in asthma: help or hindrance? Br J Clin Pharmacol. 1992 Feb;33(2):129–138. doi: 10.1111/j.1365-2125.1992.tb04014.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lipworth B. J., McDevitt D. G., Struthers A. D. Systemic beta-adrenoceptor responses to salbutamol given by metered-dose inhaler alone and with pear shaped spacer attachment: comparison of electrocardiographic, hypokalaemic and haemodynamic effects. Br J Clin Pharmacol. 1989 Jun;27(6):837–842. doi: 10.1111/j.1365-2125.1989.tb03447.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lipworth B. J., McFarlane L. C., Coutie W. J., McDevitt D. G. Evaluation of the metabolic responses to inhaled salbutamol in the measurement of beta 2-adrenoceptor blockade. Eur J Clin Pharmacol. 1989;37(3):297–300. doi: 10.1007/BF00679788. [DOI] [PubMed] [Google Scholar]
- Lipworth B. J., Tregaskis B. F., McDevitt D. G. Comparison of hypokalaemic, electrocardiographic and haemodynamic responses to inhaled isoprenaline and salbutamol in young and elderly subjects. Eur J Clin Pharmacol. 1991;40(3):255–260. doi: 10.1007/BF00315205. [DOI] [PubMed] [Google Scholar]
- Nordrehaug J. E., Johannessen K. A., von der Lippe G. Serum potassium concentration as a risk factor of ventricular arrhythmias early in acute myocardial infarction. Circulation. 1985 Apr;71(4):645–649. doi: 10.1161/01.cir.71.4.645. [DOI] [PubMed] [Google Scholar]
- Pauli B. D., Reid R. L., Munt P. W., Wigle R. D., Forkert L. Influence of the menstrual cycle on airway function in asthmatic and normal subjects. Am Rev Respir Dis. 1989 Aug;140(2):358–362. doi: 10.1164/ajrccm/140.2.358. [DOI] [PubMed] [Google Scholar]
- Sears M. R., Rea H. H., Fenwick J., Gillies A. J., Holst P. E., O'Donnell T. V., Rothwell R. P. 75 deaths in asthmatics prescribed home nebulisers. Br Med J (Clin Res Ed) 1987 Feb 21;294(6570):477–480. doi: 10.1136/bmj.294.6570.477. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stewart D. E., Ikram H., Espiner E. A., Nicholls M. G. Arrhythmogenic potential of diuretic induced hypokalaemia in patients with mild hypertension and ischaemic heart disease. Br Heart J. 1985 Sep;54(3):290–297. doi: 10.1136/hrt.54.3.290. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Struthers A. D., Reid J. L., Whitesmith R., Rodger J. C. The effects of cardioselective and non-selective beta-adrenoceptor blockade on the hypokalaemic and cardiovascular responses to adrenomedullary hormones in man. Clin Sci (Lond) 1983 Aug;65(2):143–147. doi: 10.1042/cs0650143. [DOI] [PubMed] [Google Scholar]