[Skip to content]

Search our Site
National Patient Safety Agency

Clinicians warned of the dangers of loading doses of drugs

25 November 2010

The National Patient Safety Agency (NPSA) has issued guidance for all NHS organisations across England and Wales, aimed at reducing the risk of harm or death through the incorrect use of loading doses.


A loading dose is a large dose of medicine used to ensure a quick therapeutic response. The loading dose can create complexity in prescribing, dispensing and administering medication and increase the possibility of human error.

Errors can lead to over-medication (where levels of the medication can build to excessive levels with toxic effects) or to under-medication (where harm can result from failure to effectively treat the patient’s illness).


This latest Rapid Response Report (RRR) has been produced following 1,165 patient safety incidents, between 1 January 2005 and 30 April 2010, which included two deaths and four cases of severe harm. The fatal and severe incidents were all related to incorrect loading doses, omitted or delayed administration of loading doses, or the unintentional continuation of loading doses. A further fatality was reported by coroner’s letter.


The RRR asks NHS organisations to ensure that:


• risk assessments take place of all medicines used by the organisation that are likely to cause harm if loading doses and subsequent maintenance doses are not prescribed and administered correctly.  This issued to produce a list of critical medicines which must include warfarin, amiodarone, digoxin, phenytoin and any other medicines identified locally;


• there is effective communication regarding loading dose and subsequent maintenance dose regimens when prescribing, dispensing or administering critical medicines is effective. This includes handover of patients between teams and healthcare organisations. Tools such as loading dose work sheets, loading dose prescription charts, handover and clinical protocols, and patient-held information should be considered;


• clinical checks are performed by medical, nursing and pharmacy staff (when available) so that loading and maintenance doses are correct. Appropriate information should be available to support these checks;


• healthcare professionals in the community are able to challenge abnormal doses of the identified critical medicines.


Professor David Cousins, Head of Patient Safety, Medication Practice and Medical Devices, at the NPSA, said: “The use of loading doses can be complex in practice but NHS organisations can minimise the risks of errors with loading doses by being proactive and introducing safety measures identified in this Rapid Response Report.


“Risk Assessment, effective communication and checks are the key messages to NHS staff. Loading doses are often prescribed and administered in a clinical setting from which the patient is then immediately transferred. This leads to errors where details are not communicated effectively.”

For a copy of this latest RRR, please visit http://www.nrls.npsa.nhs.uk/resources/type/alerts/?entryid45=92305



Notes to editors


1. Media enquiries to the NPSA Press Office:


Dominic Stevenson – 020 7927 9351 / dominic.stevenson@npsa.nhs.uk


Out of hours – 0788 411 5956


2. Following the publication of the Arms Length Body Review on 26 July 2010, the NPSA has stressed the importance for all NHS organisations across England and Wales to continue reporting patient safety incidents through the National Reporting and Learning System. This is so that trends in safety incidents can be identified and acted upon as early as possible.  This aspect of our work will continue within the new proposed structure of the NHS Commissioning Board and we will continue to work together in partnership with NHS organisations to make services even safer for patients.  We will continue to monitor the implementation of all patient safety alerts and guidance.