glycerol + sucrose: clinical use

Prescribing considerations

• Confirm that the cough is dry and irritating rather than requiring assessment for an underlying cause.
• Consider the substantial sucrose and glucose content in diabetes and the possible effect of repeated sugar exposure on teeth.
• Review excipients because the plain and blackcurrant formulations differ.

Contraindications and cautions

• Hypersensitivity to either active ingredient or any excipient
• Children under 1 year
• Fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency

Monitoring

• No routine laboratory monitoring is specified.
• Reassess if symptoms worsen, persist or occur with breathlessness, chest pain, systemic illness or haemoptysis.
• Monitor for hypersensitivity and consider blood-glucose effects where clinically relevant.

Clinical pharmacology

Glycerol and sucrose provide local demulcent activity. Glycerol is absorbed and mainly metabolised in the liver; sucrose is hydrolysed in the small intestine to glucose and fructose.

Formulation and product differences

• Benylin Dry & Tickly Cough Syrup is a dark-brown syrup containing black treacle and a flavour with anise oil, liquorice, propylene glycol and a small amount of ethanol.
• The children's blackcurrant syrup contains anthocyanin, blackcurrant flavour and juice, propylene glycol and a very small amount of benzyl alcohol.
• Both formulations contain sucrose, liquid glucose and sodium benzoate, and are essentially sodium-free.