Respiratory Response to Carbon Dioxide after Propranolol in Normal Subjects

Abstract

The ventilatory response to carbon dioxide, using the rebreathing technique, was investigated in 5 healthy nonsmoker volunteers, without obstructive bronchopathy. The administration of propranolol (20 mg) in a single oral dose did not produce significant modifications of the slopes of the response curves, but caused a significant increase of the intercept of the curves (p < 0.05). Since no changes of the spirographic values were noted, the results obtained were attributed to a decrease of ventilation. It is concluded that propranolol, even at the dose of 20 mg, is able to induce a depression of the respiratory center, concomitant with a significant reduction of heart rate and arterial blood pressure.

Ventilatory Response to Carbon Dioxide and to Isometric Muscle Contraction after Administration of Placebo, Propranolol, Mepindolol and Salbutamol

“…after the administration of the four drugs showed that only propranolol increased the intercept of the curve of the ventilatory response, in comparison to the value ob tained after administration of placebo. The slope of this curve was not changed as previously observed [2], Mepindolol and salbutamol did not show modification of Ve in terms of slope and intercept during rebreathing test (table III).…”

“…The results obtained by administration of propranolol gave con flicting results: in fact both a reduction of ventilatory response to CO? [2,7] and no modifications [8] have been reported.…”

Beta-Blocker Therapy with Metoprolol in the Hyperventilation Syndrome

“…There are controversies in the Patrick and Pearson [1978] found that pro pranolol had no effect on the C 0 2 response curve. Bosisio et al [1979] found a shift to the right of the ventilatory response to C 02 without change of slope after propranolol. Wc have found that metoprolol, proprano lol and exprenolol do not affect the ventila tory response to C 0 2 in healthy human sub jects [Folgering and Braakhekke, 1980], In another study where we infused beta-adre nergic drugs selectively into the vertebral artery of cats, we found an increased phren ic nerve activity after beta-mimetics and a decreased activity after beta-blockers [Fol gering, 1980], Scheen et al [1976] suggest that beta-adrenergic drugs only affect the ventilation in states of increased sympathoadrenergic activity such as exercise.…”

Differential Effects of Beta-Adrenergic Blockade on P_0.1 and Mean Inspiratory Flow

“…The measurement of ventilatory re sponse to carbon dioxide is well estab lished as a method of assessing the action of drugs on ventilatory drive [36], Pro pranolol and several other (3-adrenergic blocking drugs have been shown to have a significant influence on the CO; respon siveness [5,8,28,36], while other investi gators did not find any changes following beta-blockade [6,21,22,29,37], In all of these studies, the (modified) Read Method [31] was used and measurements were evaluated in terms of slope and intercept values [32], Unlike previous investigators, we mea sured both FIco; and PaCo; instead of PAco,. Thus, during room air breathing, the effects of bupranolol on ventilation must be interpreted with respect to PaCO; as the dependent variable.…”

“…With rebreathing techniques, however, controversial results have been reported concerning C 0 2 sensi tivity after propranolol [5,6,8,21,22,28,29,36,37] and several other (3-adrenergic blocking drugs [6,21,22,37]. From these results it is unclear whether (3-blockade af fects the ventilatory response or the C 0 2-dependent central drive.…”