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.

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 and decreased in those older than 80 years. 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 young older adults 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.