What Is Sialorrhoea? (Chronic Drooling)
Glycopyrronium bromide has a well-established history of use over more than 10 years in the United Kingdom for the treatment of sialorrhoea (chronic pathological drooling) in children with neurological disorders.
The overall prevalence of significant sialorrhoea in children is estimated at up to 0.6% (Fairhurst, 2011). However, sialorrhoea is much more common in neurologically impaired children including those with cerebral palsy (CP), the most common motor disability of childhood; estimates of the prevalence of sialorrhoea in these populations range from 10% to 40% (Parr, 2014; Parkes, 2010; Mier, 2000; Van De Heyning, 1980, Reid, 2012) but may be even higher in some subgroups, especially those with quadriplegic CP (Fairhurst, 2011; Tahmassebi, 2003a).
The UK has approximately 23,000 children with cerebral palsy. Reid et al 2012 demonstrated that 40% of children with CP have drooling of which 15% is severe. This equates to 9,200 children with CP and drooling in England of whom 1,380 cases would be classified as severe.
Uncontrolled sialorrhoea can have negative consequences for health and quality of life (QoL) due to the prodigious rate of salivation (Parr, 2014; Fairhurst, 2011; Mier, 2000; Harris, 1987; Hockstein, 2004; Van De Heyning, 1980; Van der Burg, 2006b). There may be a perception that chronic drooling is not a significant issue for affected children, but this is far from the truth. Sullivan and Rosenbloom, (1996) stated that persistence of drooling into school age leads to social isolation and the problem can be both practically and socially devastating in adolescence and childhood. Drooling children frequently have chronically irritated, macerated facial skin and in cold months the dampness from saliva is chilly. Dehydration can even become a recurrent problem as a consequence of chronic fluid and nutrient loss.
Books and papers become untidy or damaged in school or at work and electronic devices may malfunction. The ability of motor-impaired individuals to access new and sophisticated electronic technology that can offer them more opportunity to communicate and more independence is severely compromised by uncontrolled sialorrhoea. Inability to control drooling, in the face of peer pressure to do so, can result in substantial loss of self-esteem. Besides being unsightly, concerns related to hygiene and disagreeable odour alienate people. Speech spray from individuals with wet mouths is unpleasant and cough or sneeze can be a social catastrophe.
For those naïve to the problems of the developmentally disabled it requires a conscious learned effort to approach the drooler, enter into conversation or make physical contact. In itself drooling affects the general well-being of individuals and secondarily it may present problems for caregivers. Therefore its early recognition and specific treatment is essential to the overall intervention plan of the multidisciplinary team. The goal is to promote a better quality of life and to improve social interactions.
Classification of Sialorrhoea
There are several systems employed for the classification of sialorrhoea. A common method, and the one used in many clinical studies, is the modified Teacher’s Drooling Scale.
1 = Dry: never drools
2 = Mild: only the lips are wet; occasionally
3 = Mild: only the lips are wet; frequently
4 = Moderate: wet on the lips and chin; occasionally
5 = Moderate: wet on the lips and chin; frequently
6 = Severe: drools to the extent that clothing becomes damp; occasionally
7 = Severe: drools to the extent that clothing becomes damp; frequently
8 = Profuse: clothing, hands, tray, and objects become wet; occasionally
9 = Profuse: clothing, hands, tray, and objects become wet; frequently
Pathophysiology of Sialorrhoea
The pathophysiology of sialorrhea is not clear. However, the following five factors have an impact on the complex and coordinated process of swallowing and are thought to contribute in varying degrees to drooling in individuals with neurological disorders (Blasco 1992; Mier 2000):
- Integrity of oral structures;
- Oropharyngeal motor function;
- Orofacial sensory perception and feedback;
- Rate of saliva secretion; and
- Cognitive awareness of salivary spill.
Saliva production and swallowing is an automatic act. However, it is dependent on the ability to feel the build-up of saliva within the mouth and relies upon the normal movement of the tongue to collect it and transfer it to the back of the mouth for swallowing. A child will typically produce 1-1.5 liters of salvia everyday with the production predominantly occurring in three pairs of salivary glands: the submandibular, sublingual and parotid. The submandibular glands account for 65‑70% of unstimulated production of saliva so are the primary source of saliva in sialorrhoea (Fairhurst 2011, Erasmus 2009).
Management of Sialorrhoea
Several non-invasive treatment options are available as a first-line management of sialorrhoea (directed at the cause), such as practical aids, speech therapy, physiotherapy.
Further therapeutic options of increasing invasiveness exist, such as anticholinergic medication, botulinum toxin or surgical removal or ligation of some of the salivary glands.
Drug therapy is aimed at decreasing the volume of saliva without addressing impaired swallowing. Historically, a range of drugs with anticholinergic (antimuscarinic) actions have been used in an attempt to control sialorrhea.
Anticholinergic drugs work by decreasing the volume of saliva secreted from the salivary glands and thus the severity of drooling. Hyoscine (scopolamine), benztropine mesylate and benzhexol have all been shown to be useful for controlling drooling in children with neurological disorders. However, their lack of selectivity leads to widespread, undesirable, and often poorly tolerated central and peripheral effects, including restlessness, irritability, drowsiness, constipation, urinary retention, and flushing.
Glycopyrronium bromide is a water-soluble synthetic quaternary amine. It is a peripheral antimuscarinic (anticholinergic) agent. Glycopyrronium bromide acts as a competitive antagonist at muscarinic receptors in the autonomic nervous system. One of the pharmacological actions of all anticholinergic drugs is the reduction of secretions through antagonism of cholinergic M3 stimulation (Tscheng et al. 2002). Glycopyrronium bromide, administered via the intravenous (i.v.), intramuscular (i.m.), and oral routes, has been shown to reduce salivary secretions in healthy adult volunteers (Mirakhur, 1978a; Mirakhur, 1980) and surgical patients (Mirakhur, 1979b; Ali-Melkkilä, 1989; Ali-Melkkilä, 1990a). Compared with atropine, glycopyrronium bromide is selective and 6-times more potent with a longer duration of effect on salivary secretions.
Sialanar® (glycopyrronium 320micrograms/ml) equivalent to 400micrograms/ml (2mg/5ml) glycopyrronium bromide, was licensed for children throughout Europe on 15th September 2016, for the symptomatic treatment of severe sialorrhoea aged 3 years and over.
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Date created March 2020