Background: Among palliative-care patients, subcutaneous route is often an alternative to intravenous route yet pharmacological and clinical data are lacking. Many French palliative crew are now using empirically paracetamol by subcutaneous route also there is no data to support this practice. The aim of the present study is to compare pharmacokinetics parameters between intravenous and subcutaneous route for palliative-care patients.

Methods/design: A randomized, open, crossover, bicenter study in two palliative care centers. The aim is to demonstrate the pharmacokinetic equivalence between the two routes of administration. Data analysis will be performed by Wilcoxn's signed Rank Test with an alpha risk of 5 percent. All adverse events will be reported for a safety analysis.

Discussion: This trial may permit, if a pharmacokinetic equivalence is established, to build randomized controlled trials to then assess the efficacy and tolerability of subcutaneous paracetamol administration.

Inclusion Criteria:

• Patients ≥ 18 years old, hospitalized
• Patients in a palliative care situation
• Patients having an intravenous device with the presence of a venous reflux (be implantable venous site, picc-line, central track)
• Patients having a spontaneous pain, not related to care, with a numeric pain rate scale (NPRS) > 3/10 or have a systematic prescription of paracetamol in the usual treatment
• Patients able to do an auto-evaluation of their pain by NPRS
• No contraindications of paracetamol
• No contraindications of alternative antalgic (low opioids, strong opioids, Non-steroidal anti-inflammatory)
• Possibility to not take paracetamol in the previous 24 hours before inclusion
• Patients with a blood test dating back less than 7 days, with no severe renal or hepatic failure
• Patients related with a French social security regime
• Patients accept to participate in the study, with written consent.

Exclusion Criteria:

• Patients under legal protection
• Patients who participate in another study less than 30 days before
• Patients weighing less than 50 kg
• Patients having a contraindication to subcutaneous route
• Pregnant or breastfeeding woman
• Patients who having a paracetamol administration less than 24 hours before the beginning of the inclusion
• Patients who having a low opioid less than 2 hours before or a strong opioid less than one hour before the beginning of administration of paracetamol
• Patients having a fever
• No possibility of communication