Lithium dispensed for adults aged ≥ 50 years between 2012 and 2021: Analyses of a 10% sample of the Australian Pharmaceutical Benefits Scheme

Background Lithium use seems to be declining in clinical practice. We examined the proportion of adults aged ≥ 50 years dispensed lithium between 2012 and 2021, and investigated the proportion of lithium users dispensed other medications. Lithium is primarily used for the management of bipolar disorder, which affects 0.7% of older Australians. Methods We used a 10% random sample data of the Australian Pharmaceutical Benefits Scheme from 2012 to 2021, and limited our analyses to adults aged ≥ 50 years. We retrieved data on lithium, other mood stabilisers, antipsychotics, antidepressants, anxiolytics and hypnotics, and medications for the treatment of other health systems. Results We received 7081939 person-years records (53.2% women). The proportion of participants dispensed lithium decreased with age: 0.4% for those aged 50-59 years to < 0.1% for people aged ≥ 90 years. The dispensing of lithium increased over 10 years for those aged 50-69 from 0.34% in 2012 to 0.38% in 2021, and decreased in those older than 80 years from 0.19% in 2012 to 0.14% in 2021. Among people dispensed lithium, nearly 1 in 5 were dispensed another mood stabiliser. Antipsychotics and antidepressants were dispensed to about 60% of participants dispensed lithium, with antidepressants dispensed more frequently to women than men. About 20% of people dispensed lithium were dispensed anxiolytics/hypnotics, more frequently for women than men. Medications to treat diseases of the alimentary, cardiovascular, endocrine and nervous systems were commonly dispensed to those dispensed lithium, as were antibiotics. Conclusions While the dispensing of lithium increased among older adults aged 50-69 years since 2015 when guidelines for the management of mood disorders were published, our findings suggest that lithium may be under-utilised for the management of bipolar disorder in later life.