Enhancing Allopurinol Safety and Preventing Drug-Induced Injury

Hong Kong Baptist Hospital

Introduction

Hong Kong Baptist Hospital launched a medication safety initiative to prevent severe adverse reactions associated with Allopurinol, particularly Stevens-Johnson syndrome and toxic epidermal necrolysis. These life-threatening reactions are strongly linked to the HLA-B*58:01 genetic variant, present in around one in eight Hong Kong Chinese individuals.

From March 2024 to March 2025, the hospital introduced a pharmacogenomic safety model combining pre-treatment genetic screening, electronic prescribing alerts, safer alternative therapies and patient education. The initiative aimed to embed proactive risk identification into routine prescribing practice rather than relying on reactive intervention.

By integrating genetic risk screening into clinical workflows, the project strengthened medication governance and prescriber awareness. During the project period, genetic testing uptake increased substantially and no severe Allopurinol-related skin reactions were reported, demonstrating a measurable improvement in patient safety.

Challenge

Allopurinol is widely used for gout and hyperuricaemia but carries a rare yet potentially fatal risk of severe cutaneous adverse reactions in patients with the HLA-B*58:01 gene. Prior to the project, awareness of this genetic risk and the importance of screening was limited among both prescribers and patients. Testing was not routinely performed, and pharmacists relied on passive interventions to influence prescribing decisions.

Cost considerations and workflow pressures also discouraged genetic testing, while the absence of automated prescribing prompts meant opportunities for screening could be missed. As a result, at-risk patients could receive Allopurinol without genetic assessment, exposing them to preventable harm.

The hospital needed a systematic, sustainable approach to integrate pharmacogenomic screening into prescribing practice, increase clinician awareness and ensure safer treatment alternatives were considered consistently across specialties.

Approach

The one-year project combined evidence review, stakeholder engagement and digital workflow integration. A multidisciplinary team of pharmacists, clinicians and the Medication Safety Committee conducted literature review and developed local safety protocols recommending HLA-B*58:01 screening before Allopurinol initiation.

Electronic prescribing alerts were embedded to prompt genetic testing and suggest safer alternatives such as Febuxostat. Medication labels and patient information were updated to highlight early signs of adverse reactions and encourage prompt reporting.

Education sessions and cross-specialty engagement built prescriber awareness and trust, while pharmacists supported implementation and monitoring. A structured evaluation framework tracked testing uptake, prescribing compliance and adverse events. This integrated pharmacogenomic model enabled proactive risk identification and consistent safer prescribing across the hospital.

Achievements / Outcomes

The initiative delivered measurable improvements in medication safety. HLA-B*58:01 testing uptake among new Allopurinol patients increased by 56%, reflecting greater prescriber awareness and protocol adherence. Forty-one tests were conducted during the study period, with five positive results identified. All at-risk patients avoided Allopurinol, achieving 100% compliance with safety recommendations.

Safer alternatives were implemented, with 40% of positive patients switched to Febuxostat. Importantly, no severe Allopurinol-related skin reactions occurred during the project period, demonstrating effective prevention of high-risk prescribing.

Beyond individual outcomes, the project strengthened pharmacogenomic governance and embedded a culture of proactive medication safety. The model provides a foundation for extending genetic screening to other high-risk drugs and supports broader adoption of personalised medicine approaches within hospital practice.

Lessons for Others

• Embed genetic screening in prescribing workflows
• Use electronic alerts to prompt safer choices
• Engage pharmacists as safety leaders
• Educate clinicians on pharmacogenomic risk
• Provide clear alternative therapies
• Monitor compliance and outcomes
• Start with high-risk medications