Parasympathetic nervous system in nocturnal asthma

Br Med J (Clin Res Ed). 1988 May 21;296(6634):1427-9. doi: 10.1136/bmj.296.6634.1427.


To investigate the effect of vagal blockade with atropine on nocturnal fall in peak expiratory flow rate 10 patients with asthma who had a diurnal variation in peak expiratory flow rate of greater than 20% were given 30 micrograms/kg of intravenous atropine or a placebo at 4 am and 4 pm. Vagal blockade caused significant bronchodilatation at 4 am and 4 pm (peak expiratory flow rate rose from 260 to 390 l/min at 4 am and 400 to 440 l/min at 4 pm) and significantly increased the pulse rate from 60 to 121 beats/minute at 4 am and from 76 to 122 beats/minute at 4 pm. Nocturnal asthma was almost totally reversed, implying that vagal mechanisms are fundamental in its pathophysiology. Other mechanisms--diurnal changes in plasma adrenaline concentration, the activity of non-adrenergic non-cholinergic nerves, and circadian rhythms of inflammatory mediator activity--may also be implicated.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Asthma / physiopathology*
  • Atropine / pharmacology*
  • Circadian Rhythm*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Peak Expiratory Flow Rate
  • Vagus Nerve / drug effects*


  • Atropine