Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0034067 (emphysema)
 11,506 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects on ventilation of the non-selective beta-blocker propranolol, and the relatively cardioselective beta-blocker, metoprolol, were compared in a randomized single-blind crossover study in 16 patients with asthma, bronchitis and emphysema (American Thoracic Society criteria). Group I had "fixed" airways disease with less than 20% improvement in FEV1 following inhaled salbutamol 5 mg by nebuliser. Group II had "reversible" obstruction, greater than 20% improvement. Bronchodilator therapy was withheld for 24 h with the exception of aerosols which were permitted until 12 h before study. After control observations on each of 2 study days, each patient received cumulative doses of propranolol (maximum 170 mg) and metoprolol (maximum 187.5 mg). Ventilatory function (FEV1, FVC, FEV1%) was assessed at 0, 2, 4, 6 and 8 h. In Group I, 2 patients were unable to complete the study. One patient became dizzy with propranolol 70 mg but tolerated metoprolol 187.5 mg. One patient developed wheeze with propranolol 15 mg but tolerated metoprolol 187.5 mg. Metoprolol was tolerated in all 8 patients with "fixed" disease, although FEV1 was reduced by more than 30% in 1 patient. Three patients in Group II did not complete the study because of wheezing following propranolol 10 mg, metoprolol 37.5 mg; propranolol 17.5 mg, metoprolol 37.5 mg; propranolol 45 mg, tolerated metoprolol 187.5 mg respectively. Wheezing responded in all cases to inhaled isoprenaline. The response to either propranolol or metoprolol was unpredictable in patients with "reversible" disease. When wheezing occurred in this group, it developed following small, potentially subtherapeutic doses of each drug. Although metoprolol was better tolerated, the practical benefit of cardioselectivity in those patients with reversible airways disease was negligible.
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PMID:Influence of cardioselectivity and respiratory disease on pulmonary responsiveness to beta-blockade. 615 5

Ventilation, heart rate, and arterial blood gas tensions were measured at rest and during incremental exercise in 10 patients with emphysema after intravenous placebo or 7 mg metoprolol. Metoprolol reduced heart rate by 14% (P less than 0.001) and ventilation by 11% (P less than 0.01), but there was no significant difference in arterial O2 or CO2 tension (Pao2 and PaCO2, respectively). Metoprolol increased the time to exhaustion on a cycle ergometer (P less than 0.05) but did not improve the 12-min walking distance. A double-blind randomized crossover comparison of 4 wk treatment with atenolol (100 mg/day), metoprolol (100 mg/day), or matched placebo was performed in 12 patients with emphysema. Both beta-adrenoceptor antagonists reduced resting heart rate by 33% (P less than 0.001) and resting minute ventilation by 11% (P less than 0.025). There was no change in resting or exercise Pao2 or Paco2. During steady-state exercise on a cycle ergometer, atenolol and metoprolol reduced ventilation by 14 and 4%, respectively. This was accompanied by 11 and 5% reductions in O2 consumption (P less than 0.05) and 13 and 6% falls in CO2 production (P less than 0.05). There were no significant changes in tests of exercise tolerance, but forced expiratory volume in 1 s and forced vital capacity were reduced during beta 1-adrenergic blockade. beta 1-Blocking drugs reduce hyperventilation in emphysema by reducing pulmonary gas exchange without a change in arterial blood gas tensions. Increased airflow obstruction prevents this reduction being of therapeutic value.
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PMID:Effect of beta-adrenergic blockade on hyperventilation and exercise tolerance in emphysema. 686 97