Administration of label and off-label drugs by the subcutaneous route in palliative care: an observational cohort study.

Background: The marketing authorisation for many injectable drugs used in palliative care does not cover the frequently preferred subcutaneous route. Consequently, subcutaneous off-label drug administration is often practised.
Aim: To assess the use, safety and tolerability of subcutaneous label and subcutaneous off-label drug administration in a Danish hospice.
Material and Methods: Retrospective data from hospice inpatient records registered with subcutaneous drug administration. Prospective data of subcutaneous drug administration registered to hospice inpatients over a period of 2 months.
Results: Drugs were administered subcutaneously to 90% of patients in both studied cohorts. Thirty different drugs were administered subcutaneously. Ten (33%) drugs were authorised for subcutaneous administration, 14 (47%) for intramuscular and 6 (20%) for intravenous administration only. A search in major palliative literature and scientific publications revealed that 11 of the 20 subcutaneous off-labelled drugs were administered with little to no support from these sources. In seven patients, 11 adverse drug reactions (ADRs) were registered. ADRs were all minor local reactions and led to drug discontinuation in two patients only.
Conclusion: Subcutaneous drug administration was frequently used in the hospice. Two-thirds of the drugs were administered subcutaneously off-label. The findings of only a few and minor ADRs indicate that the drugs identified in this study, although often subcutaneously off-label and with little support from palliative literature, were administered with acceptable safety and tolerability. Off-label treatment practised in the clinic should be identified, reported and serve as inspiration for future scientific research and incentives for extension of marketing authorisations.
Competing Interests: Competing interests: None declared.
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