What are the differences in dosage and usage between bupivacaine (local anesthetic) and ropivacaine (local anesthetic)?

From the Guidelines

Bupivacaine and ropivacaine are both amide local anesthetics with important differences in dosing, potency, and safety profiles, with bupivacaine being more potent and ropivacaine offering a better safety profile. The most recent and highest quality study 1 provides guidance on the dosage of bupivacaine and ropivacaine for postoperative pain management in children. For wound infiltration, port-side infiltration, and peripheral nerve block, the maximum dose of bupivacaine 0.25% is 1 ml/kg (= 2.5 mg/kg) and the maximum dose of ropivacaine 0.2% is 1.5 ml/kg (= 3 mg/kg) 1. Some key points to consider when using these medications include:

• Bupivacaine is more potent than ropivacaine, typically requiring lower doses to achieve similar anesthetic effects.
• Ropivacaine offers a better safety profile with less cardiotoxicity and CNS toxicity than bupivacaine.
• Ropivacaine produces less motor blockade at equivalent analgesic concentrations, which is advantageous for ambulatory procedures and postoperative pain management.
• Onset time is similar for both drugs (10-20 minutes), but ropivacaine's duration of action (5-8 hours) is slightly shorter than bupivacaine's (6-10 hours).
• When administering either medication, always aspirate before injection, use test doses when appropriate, and have resuscitation equipment readily available. It is also important to note that the dosage and usage of bupivacaine and ropivacaine may vary depending on the specific procedure and patient population, and it is essential to consult the most recent and relevant guidelines and studies, such as those from the European Society for Paediatric Anaesthesiology 1.

From the FDA Drug Label

In 2 clinical pharmacology studies (total n=24) ropivacaine and bupivacaine were infused (10 mg/min) in human volunteers until the appearance of CNS symptoms, eg, visual or hearing disturbances, perioral numbness, tingling and others Similar symptoms were seen with both drugs. In 1 study, the mean ± SD maximum tolerated intravenous dose of ropivacaine infused (124 ± 38 mg) was significantly higher than that of bupivacaine (99 ± 30 mg) while in the other study the doses were not different (115 ± 29 mg of ropivacaine and 103 ± 30 mg of bupivacaine) Ropivacaine hydrochloride 5 mg/mL (0. 5%), was evaluated for its ability to provide anesthesia for surgery using the techniques of Peripheral Nerve Block. There were 13 studies performed including a series of 4 pharmacodynamic and pharmacokinetic studies performed on minor nerve blocks. From these, 235 ropivacaine hydrochloride‑treated patients were evaluable for efficacy. Ropivacaine hydrochloride was used in doses up to 275 mg In addition, of ropivacaine hydrochloride, 7.5 mg/mL (0. 75%), was evaluated in 99 of ropivacaine hydrochloride‑treated patients, in 2 double‑blind studies, performed to provide anesthesia for surgery using the techniques of Brachial Plexus Block. Ropivacaine hydrochloride 7.5 mg/mL was compared to bupivacaine 5 mg/mL.

The main differences in dosage and usage between bupivacaine and ropivacaine are:

• The maximum tolerated intravenous dose of ropivacaine was significantly higher than that of bupivacaine in one study, but not in another study 2.
• Ropivacaine was used in doses up to 275 mg for peripheral nerve block, while bupivacaine was compared to ropivacaine at doses of 200 mg and 150 mg in two double-blind studies 2.
• Ropivacaine and bupivacaine have similar onset, depth, and duration of sensory block, but ropivacaine has less depth and duration of motor block than bupivacaine 2. Key points to consider when choosing between bupivacaine and ropivacaine include:
• Cardiac toxicity: Ropivacaine has been shown to have less cardiac toxicity than bupivacaine in non-clinical pharmacology studies 2.
• Motor block: Ropivacaine has less motor block than bupivacaine, which may be beneficial in certain clinical situations 2.

From the Research

Comparison of Bupivacaine and Ropivacaine

• Bupivacaine and ropivacaine are both local anesthetics used for regional anesthesia, but they have different properties and uses 3, 4.
• Ropivacaine is less cardiotoxic than bupivacaine and has a greater degree of separation between motor and sensory blockade, making it a safer choice for certain applications 3, 4.
• The dosage of ropivacaine required to elicit equivalent anesthetic effects is generally higher than that of bupivacaine 3.

Dosage and Usage

• Ropivacaine has been shown to be effective at concentrations of 5 mg/ml, but not 2.5 mg/ml, for brachial plexus anesthesia 3.
• Bupivacaine is typically used at a concentration of 0.5%, while ropivacaine is used at a concentration of 0.75% 5.
• The onset time of ropivacaine is similar to that of bupivacaine, but the duration of sensory and motor block is shorter with ropivacaine 5.
• Ropivacaine has been shown to be effective for peribulbar anesthesia at a concentration of 0.75% 6.

Pharmacokinetics and Pharmacodynamics

• Ropivacaine has linear and dose-proportional pharmacokinetics, and is metabolized extensively in the liver and excreted in urine 7.
• The plasma concentrations of bupivacaine and ropivacaine are higher and remain elevated longer when used alone, compared to when used in combination with lidocaine 5.
• Ropivacaine has a reduced potential for central nervous system toxicity and cardiotoxicity due to its lower lipophilicity compared to bupivacaine 7.