Tinzaparin for venous thromboembolism in patients with renal impairment: a single-centre, prospective pilot study.

BACKGROUND: Low molecular weight heparins (LMWH) are used extensively for prophylaxis and treatment of venous thromboembolism (VTE), bridging therapy for warfarin and standard of care in cancer-associated VTE (CA-VTE). Tinzaparin has the highest molecular weight of all LMWH and relies least on renal clearance to Cockcroft-Gault creatinine clearance (CrCl) of 20 mL/min. Previous pharmacological studies have demonstrated safety and effectiveness in elderly patients. Prospective clinical trials have confirmed these findings to CrCl 20 mL/min and in CA-VTE. We describe the pilot program developed at Concord Repatriation General Hospital for tinzaparin. AIMS: We aim to confirm the deliverability of tinzaparin in patients with renal insufficiency. METHODS: Twenty patients were established on tinzaparin as therapeutic anticoagulation with CrCl or CKD-EPI estimated glomerular filtration rate (eGFR) 20-50 mL/min with an indication for anticoagulation. Tinzaparin was given as a subcutaneous injection at 175 units/kg as a single daily dose, rounded to the nearest vial size. Tinzaparin anti-Xa levels were tested at Days 2, 7 and 14 (±1 day) and transition to oral anticoagulants were allowed at clinician discretion. RESULTS: No accumulation of tinzaparin was seen into Day 14. Two patients required dose-adjustment, five patients had bleeding complications (two major, three minor) and four patients died during follow-up, all attributable to patients' comorbidities. CrCl and body surface area-standardised CrCl were significantly correlated with tinzaparin anti-Xa level only on Day 2, and this effect was lost when patients with CrCl >50 mL/min were excluded. Data from our cohort confirm the deliverability of therapeutic tinzaparin in patients with CrCl or CKD-EPI eGFR 20-50 mL/min. Bleeding and death outcomes were also comparable to other trials using tinzaparin in CA-VTE. CONCLUSION: For patients with renal insufficiency, tinzaparin represents an attractive alternative anticoagulant with once-daily administration in a range of potential indications.

Lidocaine for Neuropathic Cancer Pain (LiCPain): study protocol for a mixed-methods pilot study.

INTRODUCTION: Many patients experience unrelieved neuropathic cancer-related pain. Most current analgesic therapies have psychoactive side effects, lack efficacy data for this indication and have potential medication-related harms. The local anaesthetic lidocaine (lignocaine) has the potential to help manage neuropathic cancer-related pain when administered as an extended, continuous subcutaneous infusion. Data support lidocaine as a promising, safe agent in this setting, warranting further evaluation in robust, randomised controlled trials. This protocol describes the design of a pilot study to evaluate this intervention and explains the pharmacokinetic, efficacy and adverse effects evidence informing the design. METHODS AND ANALYSIS: A mixed-methods pilot study will determine the feasibility of an international first, definitive phase III trial to evaluate the efficacy and safety of an extended continuous subcutaneous infusion of lidocaine for neuropathic cancer-related pain. This study will comprise: a phase II double-blind randomised controlled parallel-group pilot of subcutaneous infusion of lidocaine hydrochloride 10% w/v (3000 mg/30 mL) or placebo (sodium chloride 0.9%) over 72 hours for neuropathic cancer-related pain, a pharmacokinetic substudy and a qualitative substudy of patients' and carers' experiences. The pilot study will provide important safety data and help inform the methodology of a definitive trial, including testing proposed recruitment strategy, randomisation, outcome measures and patients' acceptability of the methodology, as well as providing a signal of whether this area should be further investigated. ETHICS AND DISSEMINATION: Participant safety is paramount and standardised assessments for adverse effects are built into the trial protocol. Findings will be published in a peer-reviewed journal and presented at conferences. This study will be considered suitable to progress to a phase III study if there is a completion rate where the CI includes 80% and excludes 60%. The protocol and Patient Information and Consent Form have been approved by Sydney Local Health District (Concord) Human Research Ethics Committee 2019/ETH07984 and University of Technology Sydney ETH17-1820. TRIAL REGISTRATION NUMBER: ANZCTR ACTRN12617000747325.