PURPOSE: Investigate the impact of recent notified medicine shortages on dispensing patterns of 30, 40, 50, and 60 mg strengths of lisdexamfetamine for treatment of Attention Deficit Hyperactivity Disorder (ADHD) in Australia. METHODS: Pharmaceutical Benefits Scheme (PBS) aggregate dispensing data for 2022-2024 were analysed. Monthly dispensings and Defined Daily Doses (DDDs) for lisdexamfetamine were calculated overall and by product strength. RESULTS: From January 2022 to August 2023, there was a constant increase in overall dispensing and volume of lisdexamfetamine likely due to expansion of PBS prescribing restrictions allowing subsidy of this medicine for patients 18 years and older in February 2021. Dispensings of the 30 mg strength decreased from August 2023 corresponding with shortages of this product. Dispensings of the 50 mg peaked in October 2023 then decreased. During the shortage of the 30 and 50 mg strengths, dispensings of the 40 and 60 mg strengths increased, however, by December 2023 dispensings of these strengths were also decreasing. Dispensings of 70 mg strengths grew steadily throughout 2024. DDDs changed substantially during the shortage period suggesting that people likely transitioned to different strengths of lisdexamfetamine to maintain their dose. CONCLUSION: Dispensing patterns of lisdexamfetamine, by strength, changed significantly during the medicines shortages periods revealing potential changes in prescriber and patient behaviours, such as switching to higher strength products or using medicines intermittently, to maintain continuity of care. To facilitate quality use of medicines during shortages, dispensing patterns must be monitored so that inequities of access can be identified and addressed.