Pharmacokinetics of Subcutaneous Levetiracetam in Palliative Care Patients

Subcutaneous Levetiracetam Administration in Latino Patients on Home Care

Background: Levetiracetam has a favorable pharmacology profile to be used subcutaneously. However, its subcutaneous use is still considered off-label as this is beyond its license. The evidence base for its safety, tolerability, and efficacy is limited to observational studies. Objectives: To report the safety and efficacy of subcutaneous levetiracetam in Latino patients on home care. Design: Observational retrospective case series study. Subjects: Consecutive sample of Latino adults with life-limiting illnesses. Methods: A case series framework with 4 domains (selection, ascertainment, causality, and reporting) to ensure reporting quality was used. Additionally, 8 relevant outcomes established in a previous comprehensive review, were collected and reported. Adverse reactions were documented using the Common Terminology Criteria for Adverse Events. Results: Fifteen Latino patients with oncological and non-oncological diagnoses received subcutaneous levetiracetam for a mean of 21 days on home care. Levetiracetam was most frequently initiated subcutaneously due to loss of the oral route. The average dosage of subcutaneous levetiracetam was 1200 mg. Only 1 patient required a dose adjustment, and only 2 patients experienced a total of 5 seizures during the therapy trial. No adverse reactions were reported. Conclusions: Subcutaneous levetiracetam appears to be effective and safe. This case series of Latino patients in home care expands the evidence of its use in the home care setting. The preliminary data reported by now on multiple case series warrants robust trials.

Administration of Levetiracetam via Subcutaneous Infusion for Seizure Control in the Palliative Care Setting: A Narrative Review

This narrative review aims to summarise the information available on the use of subcutaneous (SC) levetiracetam (LEV) in the adult palliative care setting using clinical texts, databases, journals, and grey literature. A search strategy utilising Embase, Medline CINALH and Cochrane databases, as well as Google Scholar, was conducted with the mapped search terms "levetiracetam", "subcutaneous" and "palliative". LEV intravenous (IV) proprietary products are used subcutaneously, including as continuous subcutaneous infusions (CSCIs), in the adult palliative care setting. The total LEV daily dose ranged from 250 mg to 5000 mg and LEV was administered with various diluents at varying volumes. The data identified a clinical desire to mix LEV with other medications; however, the current evidence on combination compatibility is observational only and drug stability in combinations is lacking. The majority of information in the literature on SC LEV use is based on case reports and retrospective audits. Case reports, whilst at times offering more clinical detail, represent specific circumstances not necessarily applicable to a larger patient cohort. The findings of retrospective audits are limited by the documentation and detail reported at the time of patient care that may not be designed for data collection.

Subcutaneous Bolus Infusions of Undiluted Levetiracetam for End-of-Life Patients: Two Cases

We present two cases, in which end-of-life patients were inadvertently treated with bolus infusions of undiluted subcutaneous levetiracetam. The patients were treated for three and four days respectively. In both cases, the course of treatment was uneventful. Especially, no seizures, nor local irritation was observed. Administration of undiluted subcutaneous levetiracetam as intermittent bolus infusions by hand holds alluring properties for end-of-life patients. Amongst others reducing patient discomfort, increasing freedom of movement, and accessibility to essential seizure prophylaxis by eliminating the need for a syringe driver, thereby helping accommodate many patients wish to die in their own home. However, pharmacokinetics, efficacy, and safety, including the optimum dilution and administration time of the subcutaneous preparation remains to be determined in clinically controlled trials.

Subcutaneous Levetiracetam and Sodium Valproate Use in Palliative Care Patients

Palliative care patients experience seizures in different stages of their disease and may not tolerate oral medications toward the end of life. Subcutaneous infusions of levetiracetam and sodium valproate are increasingly used off-label. This retrospective analysis (conducted from January 2019 to July 2020 in Australia) reports the effectiveness and adverse effects of levetiracetam and sodium valproate delivered via subcutaneous infusion. The doses ranged from 500 to 3000 mg/d of levetiracetam and 500 to 2500 mg/d of sodium valproate. The concentrations ranged from 20 to 83 mg/mL of levetiracetam and 20 to 50 mg/mL of sodium valproate. Subcutaneous levetiracetam was given for a median duration of 6.5 days, with no seizure recurrences in 75% of patients and no reported adverse effects in any patients. Subcutaneous sodium valproate was given for a median duration of 3.5 days, with no reported seizure recurrences in 83% of patients and one report of a localized skin reaction. This analysis suggests that subcutaneous levetiracetam and sodium valproate can effectively control seizures in palliative care populations, with minimal localized reactions.

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.

Subcutaneous Levetiracetam for the Management of Seizures at the End of Life: An Audit and Updated Literature Review

Objectives: The aim of this study is to report the results of a second cycle audit of the use of subcutaneous levetiracetam (Keppra^®) and an updated literature review of management of seizures in palliative care patients. Methods: A comprehensive literature review on the use of subcutaneous levetiracetam performed in 2016 was updated. A retrospective audit of the use of subcutaneous levetiracetam for inpatients at Sir Michael Sobell House Hospice during the period of 2019-2020 was performed. Ethical approval was not required and was therefore not sought. Results: We report an additional 66 cases identified through an updated literature review and our audit. Fourteen articles were identified from the literature review, reporting a total of 120 cases where subcutaneous levetiracetam was administered. We report 19 further cases of subcutaneous levetiracetam administration between April 2019 and April 2020. Doses ranged from 500 mg to 4000 mg daily. Doses above 2000 mg were administered using a T60 syringe driver. The oral-to-subcutaneous conversion ratio was 1:1 in all but one case where the dose had to be reduced to fit a T34 syringe driver, after which the T60s were purchased. Levetiracetam was not mixed with other medications, but administered alone using water as the diluent for injection. Where necessary, the dose was appropriately adjusted for renal function. No site reactions were reported. Conclusions: Combined analysis of the 139 cases of subcutaneous levetiracetam administration suggests that this treatment continues to have a role in management of seizures at the end of life. Clinical outcomes suggest that therapeutic levels may be achieved, although there are only very limited data available with a few cases worldwide to support this. Randomized controlled trials are urgently needed to establish the efficacy and tolerability of subcutaneous levetiracetam administration.