Legacy prescribing of certain drugs, such as antidepressants and proton pump inhibitors (PPIs), is common, according to a study published in the November/December issue of the Annals of Family Medicine.

Polypharmacy is a key clinical challenge for primary care. Drugs that should be prescribed for an intermediate term (longer than 3 months, but not indefinitely) that are not appropriately discontinued could contribute to polypharmacy.

The researchers named this type of prescribing legacy prescribing. Commonly prescribed drugs with legacy prescribing potential include antidepressants, bisphosphonates, and proton pump inhibitors (PPIs). They evaluated the proportion of legacy prescribing within these drug classes.

Primary Care Practice

Dee Mangin, M.B.Ch.B., D.P.H., from McMaster University in Hamilton, Ontario, Canada, and colleagues analyzed data from the McMaster University Sentinel and Information Collaboration (MUSIC) Primary Care Practice Based Research Network.

The authors used data from 50,813 adult patients from 2010 to 2016 to calculate rates of legacy prescriptions for antidepressants (>15 months), bisphosphonates (>5.5 years), and PPIs (>15 months).

The researchers found that 46% of patients had a legacy prescription (3,766 of 8,119) for antidepressants at some time during the study period, 14%(228 of 1,592) had legacy prescriptions for bisphosphonates, and 45% (2,885 of 6,414) had legacy prescriptions for PPIs.

Many patients held current prescriptions. For all legacy prescriptions, the mean duration of prescribing was significantly longer than that for nonlegacy prescriptions. A potential prescribing cascade was seen with concurrent legacy prescriptions for both antidepressants and PPIs.

The proportion of patients having a legacy prescription at some time during the study period was 46% (3,766 of 8,119) for antidepressants, 14% (228 of 1,592) for bisphosphonates, and 45% (2,885 of 6,414) for PPIs.

Many of these patients held current prescriptions. The mean duration of prescribing for all legacy prescriptions was significantly longer than that for non–legacy prescriptions (P <.001). Concurrent legacy prescriptions for both antidepressants and PPIs was common, signaling a potential prescribing cascade.

"These data demonstrate the potential of legacy prescribing to contribute to unnecessary polypharmacy, providing an opportunity for system-level intervention in primary care with enormous potential benefit for patients," the authors write.

The phenomenon of legacy prescribing appears prevalent. These data demonstrate the potential of legacy prescribing to contribute to unnecessary polypharmacy, providing an opportunity for system-level intervention in primary care with enormous potential benefit for patients.