Pharmacokinetic Study of Intravenous Lidocaine in Young and Elderly Patients

Summary

Aging is accompanied by a gradual alteration in the functional reserve of several organs and a change in body composition that can affect the pharmacokinetics, response, and safety profile of medications. Lidocaine is a local anesthetic used daily in perineural or intravenous administration to reduce the need for opioids. Although its analgesic efficacy is well-established, there is currently only one older study regarding the pharmacokinetics and pharmacokinetic-pharmacodynamic (PK-PD) relationship of lidocaine in healthy elderly patients. In this study, conducted with a small sample size (13 subjects over 64 years old and 24 young subjects under 38 years old) and using a low bolus of 25 mg, the half-life of lidocaine was increased by 59% and clearance was decreased by 35% in elderly male subjects without significant differences in females. However, the recommendations for intravenous administration of lidocaine for analgesic purposes are the same for all: a bolus of 1 to 2 mg/kg followed by continuous administration of 1.5 to 2 mg/kg/h. Morphine sparing is particularly important in elderly patients due to their increased sensitivity to adverse effects. With this study, the investigators aim to define the optimal dose to administer in elderly subjects, in order to optimize analgesia while remaining within the therapeutic range to limit the adverse effects of lidocaine.

Conditions

• Anesthesia

Interventions

OTHER

Pre-inclusion

Information and presentation of the proposed study to participants during the anesthesia consultation scheduled prior to surgery, including provision of the information document and consent form. Trial participants will have at least 2 days to decide whether or not to take part in the trial.

OTHER

Inclusion

Participants will be welcomed according to the usual process in the digestive, hepatic, urological, or gynecological surgery service. The inclusion visit will coincide with the pre-anesthesia visit during which the absence of contraindications for starting the study will be verified, particularly the occurrence of any health changes since the anesthesia visit that would contraindicate anesthesia or lidocaine administration. During this visit, participant consent will be obtained. The informed consent form must be signed no later than the morning of the intervention. For women of childbearing age, the absence of current pregnancy will be verified orally for each participant included. A pregnancy test may be performed if the participant so wishes, but a systematic test is not justified.

DRUG

Lidocaine

Induction of anesthesia will be at the discretion of the attending anesthesiologist, with a lidocaine bolus of 2 mg/kg administered over 1 minute, followed by a continuous IV infusion of 2 mg/kg/h.

OTHER

Pharmacokinetic study of intravenous lidocaine

Blood samples of 3 mL will be collected in heparinized tubes without gel of 4 ml at 30, 60 and 120 minutes after the start of lidocaine infusion, then every two hours during surgery, and two finals samples at 15 and 60 minutes after the infusion stops.

OTHER

Pain

. Maximal pain reported in the post-anesthesia care unit (PACU) and maximal pain at rest and with movement at 24 hours post-extubation will be recorded.

OTHER

adverse effects/events

Any adverse effects/events will be documented from the start of lidocaine administration until 24 hours post-extubation,

BIOLOGICAL

biological blood test

A biological blood test, not performed in routine practice, will be carried out to measure the following parameters: albumin, ASAT, ALAT, PAL, GammaGT, total and conjugated bilirubin, creatinine, with calculation of GFR.

Sponsors & Collaborators

• Rennes University Hospital

  lead OTHER

Study Design

Allocation

NON_RANDOMIZED

Purpose

OTHER

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-04-28

Primary Completion

2027-02-01

Completion

2027-02-01

Countries

• France

Study Locations