OBJECTIVES: Lidocaine 5% medicated plaster was licensed in Ireland in Oct 2010 for the symptomatic relief of neuropathic pain associated with previous herpes zoster infection (post-herpetic neuralgia, PHN) in adults and reimbursed since January 2011. The Medicines Management Programme (MMP) was established in 2013 to promote safe, effective and cost-effective prescribing. It monitors the utilisation of high cost drugs. The aim of this study is to review the increasing utilisation and expenditure on lidocaine 5% medicated plasters in Ireland. METHODS: Pharmacy claims data from the General Medical Services (GMS) scheme, which covers 60% of public drug expenditure in Ireland, was analysed using Microsoft Excel® and JMP® 8. The number of patients and expenditure on lidocaine 5% medicated plasters was reviewed from January 2012 to December 2015. RESULTS: Monthly GMS expenditure increased from approximately €0.4million to €2million with a corresponding increase in patient numbers from 2,994 to 16,412 from January 2012 to December 2015. Total expenditure in 2015 was €24.2million, a €16.7million increase from 2012. The MMP advised the Health Service Executive (HSE) in accordance with the Health Act 2013 (section 18(4)), to examine its cost-effectiveness and this analysis was completed by the National Centre for Pharmacoeconomics (NCPE) in September 2015. The NCPE concluded that this product did not demonstrate cost-effectiveness and only approximately 5-10% of patients receive the product for the licensed indication of PHN. The HSE negotiated a price reduction from €93.96 to €77.52 per pack in March 2016. The MMP has issued prescribing guidance to highlight the inappropriate prescribing of this medication as there is a lack of clinical evidence to support unlicensed use. CONCLUSIONS: This study demonstrates the potential for higher drug utilisation and increased budget impact when prescribing is not restricted to the licensed indication post evaluation. It also highlights the importance of medicines management post Health Technology Assessment (HTA).