From the FDA Drug Label
These doses may be repeated up to once every three hours. The minimum time interval before bupivacaine can be repeated for a regional block after administering the maximum dose is three hours 1.
From the Research
Bupivacaine should not be repeated for at least 3-4 hours after administering the maximum dose of 2 mg/kg for regional block. This waiting period is necessary because bupivacaine has a relatively long half-life of approximately 2.7 hours in adults and even longer in neonates and children, as supported by the study published in 2018 2. The drug accumulates in the body, and administering additional doses too soon can lead to systemic toxicity, including cardiovascular depression and central nervous system effects.
When planning to repeat the dose, it's essential to consider patient factors such as age, weight, liver function, and cardiovascular status, as these affect drug metabolism and clearance. For prolonged analgesia requirements, consider using a continuous catheter technique with a lower concentration (0.125-0.25%) rather than repeated bolus injections, as suggested by the study published in 2013 3. Always monitor the patient for signs of toxicity such as perioral numbness, metallic taste, tinnitus, seizures, or arrhythmias before administering additional doses.
The sequence of administration of different local anesthetics, such as mepivacaine and bupivacaine, does not seem to have a clinically meaningful effect on duration or onset of ultrasound-guided interscalene brachial plexus block, as found in the study published in 2012 4. However, the primary concern remains the safe administration of bupivacaine, ensuring that the minimum time interval is respected to avoid toxicity.
Key considerations for bupivacaine administration include:
- Minimum time interval of 3-4 hours between doses
- Patient factors affecting drug metabolism and clearance
- Use of continuous catheter technique for prolonged analgesia
- Monitoring for signs of toxicity before administering additional doses
- Awareness of the drug's pharmacokinetics, as discussed in the study published in 2018 2.