Effect of single doses of labetalol, metoprolol, and placebo on ventilatory function in patients with bronchial asthma: interaction with isoproterenol

The Journal of Asthma : Official Journal of the Association for the Care of Asthma
C J FalliersM Medakovic


The effects of labetalol, metoprolol, and placebo on pulmonary function and their interaction with isoproterenol were evaluated in 18 patients with reversible bronchial asthma [isoproterenol-induced increase in forced expiratory volume in 1 second (FEV1) of greater than or equal to 15%]. Two dose levels of each medication were studied (on consecutive days), with the lower doses of these drugs given randomly. When the lowest values during the 2-hour postdrug evaluation period were considered, FEV1 significantly increased (10.9%; 15.4%) following labetalol (200 and 400 mg, respectively), significantly decreased (-11.2%; -5.4%) after metoprolol (100 and 200 mg, respectively), and was unchanged after placebo. The effects of the three treatments on forced vital capacity (FVC) and maximal midexpiratory flow (MMEF) were qualitatively similar to those observed in FEV1. When isoproterenol was administered following labetalol (200 and 400 mg), FEV1 further increased with a resulting combined increase of 18.9 and 19.7%, respectively, indicating an additive interaction. The effect of isoproterenol was blunted by metoprolol (100 and 200 mg) (p less than 0.01, difference from the effect observed after labetalol and isoproterenol), indicating...Continue Reading


Jun 19, 2001·The Cochrane Database of Systematic Reviews·S SalpeterE Salpeter
Jan 23, 2004·The Journal of Asthma : Official Journal of the Association for the Care of Asthma·Timothy SelfCarol C Chafin
Jan 10, 2003·The Cochrane Database of Systematic Reviews·S SalpeterE Salpeter


May 1, 1978·British Journal of Clinical Pharmacology·M K BensonG M Sterling
Feb 8, 1975·Lancet·K R Patel, J W Kerr
Apr 12, 1975·British Medical Journal·C SkinnerK N Palmer
Apr 1, 1977·British Journal of Clinical Pharmacology·J G MaconochieD A Richards
Dec 1, 1975·British Journal of Clinical Pharmacology·A GeumeiW F Miller
Feb 1, 1972·British Journal of Pharmacology·J G CollierB F Robinson
Oct 5, 1974·British Medical Journal·S BiancoF J Prime
Aug 1, 1972·British Journal of Pharmacology·J B FarmerR J Marshall
Jul 18, 1981·British Medical Journal·G M Lees
Dec 1, 1981·The Journal of Pharmacy and Pharmacology·J R Carpenter
Jan 1, 1982·Clinical and Experimental Hypertension. Part A, Theory and Practice·W R AdamC E Barter
Jul 1, 1981·British Journal of Clinical Pharmacology·H R GribbinA E Tattersfield
Jan 1, 1981·European Journal of Clinical Pharmacology·M E EllisS H Ellis

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Expiratory Airflow
Diastolic Blood Pressure
Vital Capacity Test
Antihypertensive Agents
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