Greater Glasgow and Clyde Medicines

Drug Safety Update – Laxatives and the use of starch-based thickeners

Reducing the risk of aspiration in those patients taking thickened fluids and using polyethylene glycol/macrogol laxatives

Key messages

• Mixing polyethylene glycol/macrogol laxatives (e.g. Laxido®, Movicol®) with starch-based thickeners (see table below) poses a risk to patients with dysphagia

• Combining the two compounds results in a thinner, watery fluid, increasing the risk of aspiration

• Action is required to ensure that patients are not using a starch-based thickener in combination with a macrogol laxative (see recommendations below)

• The current preferred list first line thickening product in NHSGGC is xanthan gum-based Nutilis® Clear which can be used with macrogol laxatives

Brief background

A recent MHRA Drug safety update (April 2021) highlighted a potential aspiration risk to patients prescribed macrogol laxatives who also thicken their fluids using a starch-based thickener. Some people with dysphagia are unable to swallow thin liquids due to the risk of aspiration and as a result require thickened fluids. They are normally assessed by Speech and Language Therapy and advised on a suitable consistency of thickened fluids in order to reduce the aspiration risk. The two main types of thickening agent on prescription are starch-based and xanthan gum-based. Below are examples:

(if viewing table on mobile device, switch to landscape)

This requirement to thicken fluids also applies to liquid medications. This includes the group of macrogol laxatives such as Laxido®, Movicol®, Moviprep® and macrogol 3350. These medications come in sachet form and are mixed with water before taking orally. Refer to Specialist Pharmacy Service for further information on thickeners.

Recommendations

• Patients with dysphagia who are likely to be using macrogol laxatives in the management of constipation should be reviewed to ensure they are not using a starch-based thickener. Patient groups such as the elderly and those with learning disabilities are more likely to be on this combination
• If a patient is identified to be on a starch-based thickener and a macrogol laxative, the laxative or the thickener must be changed
• If the macrogol laxative cannot be changed, the thickener must be reviewed with a view to switching to Nutilis® Clear, where deemed appropriate by a healthcare professional experienced in the use of thickening agents
• Patients/carers/nursing staff should be educated about any change to thickening agents as the instructions on how to prepare may differ
• During hospital admissions, thickeners should be prescribed on the drug Kardex/HEPMA to aid identification of this issue (note HEPMA and GP practice systems do not show this as an interaction)
• Report suspected adverse drug reactions (ADRs) to the Yellow Card Scheme
  

Published 01/10/21. Medicines Update blogs are correct at the time of publication