Effect of salbutamol on the cardiovascular response in healthy subjects at rest, during physical exercise, and in recovery phase: a randomized, double-blind, crossover study

Aim: To evaluate the effect of the short-acting beta agonists (SABAs) salbutamol on cardiovascular response rest, exercise and recovery phase. Methods: This study was conducted as a randomized, double-blind, placebo controlled, crossover study in 15 healthy adults, with a mean age of 30.2±6.6 years. Participants underwent a maximal effort test on two non-consecutive days with 400 mcg of salbutamol or placebo. Throughout the protocol, the variables HR, blood pressure (BP), perceived rate of effort (modified Borg scale) and peak expiratory flow (PEF) were monitored. After salbutamol, baseline HR and PEF had increase from 71±8 to 80±11 bpm (p<0.05) and 454.0±64.5 to 475.3±71.4 L/min (p < 0.05), respectively. The variables HR, BP and Borg were similar between interventions during all the protocol phases (p>0.05). Conclusion: Administration of salbutamol increased rest heart rate; however, did not change heart rate, blood pressure and perceived exertion during exercise or recovery. This suggests that the salbutamol administration is safe and does not affect exercise intensity prescription in healthy subjects.(AU)

effect of different lipophyllic beta-blockers on the minimal electro-shock seizure threshold [MEST] in mice

The effect of different beta-blockers on the minimal electro-shock seizure threshold [MEST] in mice, an index of generalized seizure susceptibility, was studied. Equipolent doses of the lipophilic beta-adrenergic blockers propranolol, pindolol,.oxprenolol and metoprolol significantly reduced the MEST after acute or chronic use [P < 0.05], however, this reduction was not significantly dose-dependant or significantly different between them. These drugs also antagonised the effect of beta agonists sulbutamol and isoprenaline, as well as that of the antiepileptic drugs phenytoin, valproate and clonazepam in elevating the seizure threshold. No significant change in blood glucose level or brain GABA content accompanied these acute or chronic effects on MEST, except for propranolol. It is concluded that lipophylic beta-adrenergic blockers enhanced seizure susceptibility mainly by blocking beta-adrenoceptors in brain. The magnitude of. this effect does not seem to be significantly altered by the selectivity of the beta block or by the possession of partial agonist activity by some of these drugs