Subcutaneous Drugs and Off-label Use in Hospice and Palliative Care: A Scoping Review

Background Subcutaneous drug administration is an interesting approach for symptom control in hospice and palliative care. However, most drugs have no marketing authorization for subcutaneous administration and are therefore used off-label. In order to meet the requirements of a safe and effective drug therapy, especially in highly vulnerable patients, it is essential to investigate the scope of evidence of these common practices. Objectives The purpose of this scoping review was to provide an overview of available data on the tolerability and/or effectiveness of subcutaneously administered and off-label used drugs. Method We performed a scoping review according to the PRISMA extension to identify data available on the tolerability and/or effectiveness of 17 predefined drugs that are commonly administered subcutaneously in Swiss hospices and hospice-like institutions and that have no marketing authorization (off-label use). Results The scoping review identified 57 studies with most data available on their tolerability (68% local, 54% systemic), clinical effects (82%), details on dosage (96%) and routes of application (100%). Information on pharmacokinetic properties was mostly missing and only available for fentanyl, levetiracetam, midazolam, and ondansetron. For seven drugs, less than five articles were identified and no studies on codeine or clonazepam were available. Conclusion This work provides an overview of current evidence on subcutaneous and off-label used drugs in hospice and palliative care. Although both are common practices, evidence on tolerability and effectiveness, particularly pharmacokinetic data, is limited and the identified information gaps need to be closed. This work establishes a basis for further research in this area.