Comparison of the Effects of Atropine and Glycopyrrolate on Various End-Organs

Abstract

Summary: Atropine and glycopyrrolate (glycopyrronium bromide), a quaternary ammonium drug, were evaluated in volunteers following intramuscular administration with respect to effects on various end-organs with cholinergic innervation. Glycopyrrolate appears to be five to six times more potent than atropine in its antisialogogue effect and also exhibits a selective, though prolonged, effect on salivary secretion and sweat gland activity. It has minimal cardiovascular, ocular and central nervous system effects. hntroduction Atropine has for long been one of the main anticholinergic drugs employed in anaesthetic practice. It has significant actions on most systems which are cholinergically innervated. However, it suffers from some disadvantages. These include a relatively short duration of action (Eger 1962 Glycopyrrolate (glycopyrronium bromide) is a quaternary ammonium anticholinergic compound which, being highly polar, does not cross the blood-brain barrier. Initial studies in volunteers have shown it to be a potent antisialogogue agent (Wyant & Kao 1974). The present paper compares some of the actions of intramuscular atropine and glycopyrrolate in volunteers. MethodsSix adult volunteer anaesthetists participated in the study, the nature of which had been fully explained to them. Each received three doses of atropine (0.5, 1.0 and 2.0 mg) and three doses of glycopyrrolate (0.1, 0.2 and 0.4 mg) given by deep intramuscular injection. The subjects were each studied for six hours, at intervals of one week. Drugs were given in random order and observations made before and for six hours after administration.Baseline observations were recorded after resting for 30 minutes. Measurements included heart rate, blood pressure, salivary secretion, sweat gland activity, pupillary size, oral temperature and the near point of vision. The detailed methodology has been described previously .Due to the skewed distribution of measurements of salivary secretion and sweat gland activity, these data were subjected to a Wilcoxan matched-pairs signed-ranks test for determination of their statistical significance, other results being subjected to a paired t test. The dose-response curves were subjected to an analysis of covariance. ResultsThe means ages and weights of the volunteers were 32 years and 62 kg respectively. Salivary secretion: The effects ofboth drugs were dose-related (Figure 1). The salivary secretion was reduced by 43, 72 and 85% with 0.5, 1.0 and 2.0 mg atropine respectively, the peak effect

A multicentre evaluation of oropharyngeal secretion management practices in amyotrophic lateral sclerosis

“…The use of glycopyrronium was generally preferred as second line. Further consideration could be given to this treatment as a first line option, especially given its relatively low rates of adverse effects, in part due to its poor penetration of the blood brain barrier [25].…”

A study comparing hyoscine hydrobromide and glycopyrrolate in the treatment of death rattle

“…[11][12][13] The dose of glycopyrrolate given in phase II of our study (0.2 mg) was therefore not quite equipotent to the hyoscine given in phase I. A review of the literature on the antisialogogue effects of antimuscarinics showed that glycopyrrolate has a slower onset of antisialogogue action than hyoscine HBr in the normal dose ranges.…”

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“…If bradycardia occurs because too much dexmedetomidine has been administered too quickly it can be treated readily with atropine. Atropine is preferred to glycopyrrolate for serious bradycardia because it has stronger effect on cardiac muscarinic receptors [58]. Ephedrine and epinephrine can also be used to treat bradycardia if hypotension is present.…”