14 CLINICAL STUDIES
Ropivacaine was studied as a local anesthetic both for surgical anesthesia and for acute pain management [see Dosage and Administration (2)].
The onset, depth and duration of sensory block are, in general, similar to bupivacaine. However, the depth and duration of motor block, in general, are less than that with bupivacaine.
14.1 Epidural Administration in Surgery
There were 25 clinical studies performed in 900 patients to evaluate ropivacaine epidural injection for general surgery. Ropivacaine hydrochloride was used in doses ranging from 75 to 250 mg. In doses of 100 to 200 mg, the median (1st to 3rd quartile) onset time to achieve a T10 sensory block was 10 (5 to 13) minutes and the median (1st to 3rd quartile) duration at the T10 level was 4 (3 to 5) hours [see Dosage and Administration (2.2)]. Higher doses produced a more profound block with a greater duration of effect.
14.2 Epidural Administration in Cesarean Section
A total of 12 studies were performed with epidural administration of ropivacaine for cesarean section. Eight of these studies involved 218 patients using the concentration of 5 mg/mL (0.5%) in doses up to 150 mg. Median onset measured at T6 ranged from 11 to 26 minutes. Median duration of sensory block at T6 ranged from 1.7 to 3.2 h, and duration of motor block ranged from 1.4 to 2.9 h. Ropivacaine provided adequate muscle relaxation for surgery in all cases.
In addition, 4 active controlled studies for cesarean section were performed in 264 patients at a concentration of 7.5 mg/mL (0.75%) in doses up to 187.5 mg. Median onset measured at T6 ranged from 4 to 15 minutes. Seventy-seven to 96% of ropivacaine-exposed patients reported no pain at delivery. Some patients received other anesthetic, analgesic, or sedative modalities during the course of the operative procedure.
14.3 Epidural Administration in Labor and Delivery
A total of 9 double-blind clinical studies, involving 240 patients were performed to evaluate ropivacaine for epidural block for management of labor pain. When administered in doses up to 278 mg as intermittent injections or as a continuous infusion, ropivacaine hydrochloride produced adequate pain relief.
A prospective meta-analysis on 6 of these studies provided detailed evaluation of the delivered newborns and showed no difference in clinical outcomes compared to bupivacaine. There were significantly fewer instrumental deliveries in mothers receiving ropivacaine as compared to bupivacaine.
Ropivacaine N = 199
Bupivacaine N = 188
14.4 Epidural Administration in Postoperative Pain Management
There were 8 clinical studies performed in 382 patients to evaluate ropivacaine hydrochloride 2 mg/mL (0.2%) for postoperative pain management after upper and lower abdominal surgery and after orthopedic surgery. The studies utilized intravascular morphine via PCA as a rescue medication and quantified as an efficacy variable.
Epidural anesthesia with ropivacaine hydrochloride 5 mg/mL, (0.5%) was used intraoperatively for each of these procedures prior to initiation of postoperative ropivacaine hydrochloride. The incidence and intensity of the motor block were dependent on the dose rate of ropivacaine hydrochloride and the site of injection. Cumulative doses of up to 770 mg of ropivacaine were administered over 24 hours (intraoperative block plus postoperative continuous infusion). The overall quality of pain relief, as judged by the patients, in the ropivacaine groups was rated as good or excellent (73% to 100%). The frequency of motor block was greatest at 4 hours and decreased during the infusion period in all groups. At least 80% of patients in the upper and lower abdominal studies and 42% in the orthopedic studies had no motor block at the end of the 21-hour infusion period. Sensory block was also dose rate‑dependent and a decrease in spread was observed during the infusion period.
A double-blind, randomized, clinical trial compared lumbar epidural infusion of ropivacaine hydrochloride (n=26) and bupivacaine (n=26) at 2 mg/mL (8 mL/h), for 24 hours after knee replacement. In this study, the pain scores were higher in the ropivacaine hydrochloride injection group, but the incidence and the intensity of motor block were lower.
Continuous epidural infusion of ropivacaine hydrochloride 2 mg/mL (0.2%) during up to 72 hours for postoperative pain management after major abdominal surgery was studied in 2 multicenter, double-blind studies. A total of 391 patients received a low thoracic epidural catheter, and ropivacaine hydrochloride 7.5 mg/L (0.75%) was given for surgery, in combination with GA. Postoperatively, ropivacaine hydrochloride 2 mg/mL (0.2%), 4 to 14 mL/h, alone or with fentanyl 1, 2, or 4 mcg/mL was infused through the epidural catheter and adjusted according to the patient’s needs. These studies support the use of ropivacaine hydrochloride 2 mg/mL (0.2%) for epidural infusion at 6 to 14 mL/h (12 to 28 mg) for up to 72 hours and demonstrated adequate analgesia with only slight and nonprogressive motor block in cases of moderate to severe postoperative pain.
Clinical studies with 2 mg/mL (0.2%) ropivacaine hydrochloride have demonstrated that infusion rates of 6 to 14 mL (12 to 28 mg) per hour provide adequate analgesia with nonprogressive motor block in cases of moderate to severe postoperative pain. In these studies, this technique resulted in a significant reduction in patients’ morphine rescue dose requirement. Clinical experience supports the use of ropivacaine epidural infusions for up to 72 hours.
14.5 Peripheral Nerve Block
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-treated patients were evaluable for efficacy. Ropivacaine hydrochloride was used in doses up to 275 mg. When used for brachial plexus block, onset depended on technique used. Supraclavicular blocks were consistently more successful than axillary blocks. The median onset of sensory block (anesthesia) produced by ropivacaine 0.5% via axillary block ranged from 10 minutes (medial brachial cutaneous nerve) to 45 minutes (musculocutaneous nerve). Median duration ranged from 3.7 hours (medial brachial cutaneous nerve) to 8.7 hours (ulnar nerve). The 5 mg/mL (0.5%) ropivacaine hydrochloride solution gave success rates from 56% to 86% for axillary blocks, compared with 92% for supraclavicular blocks.
In addition, ropivacaine hydrochloride, 7.5 mg/mL (0.75%), was evaluated in 99 ropivacaine-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. In 1 study, patients underwent axillary brachial plexus block using injections of 40 mL (300 mg) of ropivacaine hydrochloride, 7.5 mg/mL (0.75%) or 40 mL injections of bupivacaine, 5 mg/mL (200 mg). In a second study, patients underwent subclavian perivascular brachial plexus block using 30 mL (225 mg) of ropivacaine hydrochloride, 7.5 mg/mL (0.75%) or 30 mL of bupivacaine 5 mg/mL (150 mg). There was no significant difference between the ropivacaine and bupivacaine groups in either study with regard to onset of anesthesia, duration of sensory blockade, or duration of anesthesia.
The median duration of anesthesia varied between 11.4 and 14.4 hours with both techniques. In one study, using the axillary technique, the quality of analgesia and muscle relaxation in the ropivacaine group was judged to be significantly superior to bupivacaine by both investigator and surgeon. However, using the subclavian perivascular technique, no statistically significant difference was found in the quality of analgesia and muscle relaxation as judged by both the investigator and surgeon. The use of ropivacaine hydrochloride 7.5 mg/mL for block of the brachial plexus via either the subclavian perivascular approach using 30 mL (225 mg) or via the axillary approach using 40 mL (300 mg) both provided effective and reliable anesthesia.
14.6 Local Infiltration
A total of 7 clinical studies were performed to evaluate the local infiltration of ropivacaine to produce anesthesia for surgery and analgesia in postoperative pain management. In these studies 297 patients who received ropivacaine hydrochloride in doses up to 200 mg (concentrations up to 5 mg/mL, 0.5%) were evaluable for efficacy. With infiltration of 100 to 200 mg ropivacaine hydrochloride, the time to first request for analgesic was 2 to 6 hours. When compared to placebo, ropivacaine produced lower pain scores and a reduction of analgesic consumption.