Ropivacaine Hydrochloride

NAROPIN is indicated for the production of local or regional anesthesia for surgery and for acute pain management. Surgical Anesthesia : epidural block for surgery including cesarean section; major nerve block; local infiltration Acute Pain Management : epidural continuous infusion or intermittent bolus, e.g., postoperative or labor; local infiltration NAROPIN is an amide local anesthetic indicated in adults for the production of local or regional anesthesia for surgery and for acute pain management. Surgical Anesthesi a: epidural block for surgery including cesarean section; major nerve block; local infiltration Acute Pain Management : epidural continuous infusion or intermittent bolus, e.g., postoperative or labor; local infiltration

NAROPIN ® (ropivacaine hydrochloride) injection is a clear, colorless, preservative-free solution available as: NAROPIN ® Single Dose Vials

• 0.5%, 150 mg per 30 mL (5 mg/mL), 30 mL single-dose vial
• Injection: 5 mg/mL (0.5%) in single-dose vials ( 3 )

NAROPIN is contraindicated in patients with a known hypersensitivity to ropivacaine or to any local anesthetic agent of the amide type. History of hypersensitivity to local anesthetics of the amide type. ( 4 )

• Delay in proper management of dose-related toxicity, underventilation, and/or altered sensitivity may lead to the development of acidosis, cardiac arrest and, possibly, death. ( 5.1 )
• In performing NAROPIN blocks, unintended intravenous injection is possible and may result in cardiac arrhythmia or cardia arrest. ( 5.2 )
• Intra-articular infusions of local anesthetics may cause chondrolysis. NAROPIN is not approved for this use. ( 5.3 ).
• Signs of methemoglobinemia may occur. ( 5.4 )

5.1 General Warnings and Precautions Prior to receiving major blocks the general condition of the patient should be optimized and the patient should have an IV line inserted. All necessary precautions should be taken to avoid intravascular injection. Local anesthetics should only be administered by clinicians who are well versed in the diagnosis and management of dose-related toxicity and other acute emergencies which might arise from the block to be employed, and then only after insuring the immediate (without delay) availability of oxygen, other resuscitative drugs, cardiopulmonary resuscitative equipment, and the personnel resources needed for proper management of toxic reactions and related emergencies [see Adverse Reactions ( 6 ) and Overdosage ( 10.1 )]. Delay in proper management of dose-related toxicity, underventilation from any cause, and/or altered sensitivity may lead to the development of acidosis, cardiac arrest and, possibly, death. The safe and effective use of local anesthetics depends on proper dosage, correct technique, adequate precautions and readiness for emergencies. Resuscitative equipment, oxygen and other resuscitative drugs should be available for immediate use [see Adverse Reactions ( 6 )] . The lowest dosage that results in effective anesthesia should be used to avoid high plasma levels and serious adverse events. Injections should be made slowly and incrementally, with frequent aspirations before and during the injection to avoid intravascular injection. When a continuous catheter technique is used, syringe aspirations should also be performed before and during each supplemental injection. During the administration of epidural anesthesia, it is recommended that a test dose of a local anesthetic with a fast onset be administered initially and that the patient be monitored for central nervous system and cardiovascular toxicity, as well as for signs of unintended intrathecal administration before proceeding. When clinical conditions permit, consideration should be given to employing local anesthetic solutions, which contain epinephrine for the test dose because circulatory changes compatible with epinephrine may also serve as a warning sign of unintended intravascular injection. An intravascular injection is still possible even if aspirations for blood are negative. Administration of higher than recommended doses of NAROPIN to achieve greater motor blockade or increased duration of sensory blockade may result in cardiovascular depression, particularly in the event of inadvertent intravascular injection. Tolerance to elevated blood levels varies with the physical condition of the patient. Debilitated, elderly patients and acutely ill patients should be given reduced doses commensurate with their age and physical condition. Local anesthetics should also be used with caution in patients with hypotension, hypovolemia or heart block. Solutions of NAROPIN should not be used for the production of obstetrical paracervical block anesthesia, retrobulbar block, or spinal anesthesia (subarachnoid block) due to insufficient data to support such use. Intravenous regional anesthesia (bier block) should not be performed due to a lack of clinical experience and the risk of attaining toxic blood levels of ropivacaine. It is essential that aspiration for blood, or cerebrospinal fluid (where applicable), be done prior to injecting any local anesthetic, both the original dose and all subsequent doses, to avoid intravascular or subarachnoid injection. However, a negative aspiration does not ensure against an intravascular or subarachnoid injection.

5.2 Unintended Intravenous Injection In performing NAROPIN blocks, unintended intravenous injection is possible and may result in cardiac arrhythmia or cardiac arrest. The potential for successful resuscitation has not been studied in humans. There have been rare reports of cardiac arrest during the use of NAROPIN for epidural anesthesia or peripheral nerve blockade, the majority of which occurred after unintentional accidental intravascular administration in elderly patients and in patients with concomitant heart disease. In some instances, resuscitation has been difficult. Should cardiac arrest occur, prolonged resuscitative efforts may be required to improve the probability of a successful outcome. NAROPIN should be administered in incremental doses. It is not recommended for emergency situations, where a fast onset of surgical anesthesia is necessary. Historically, pregnant patients were reported to have a high risk for cardiac arrhythmias, cardiac/circulatory arrest and death when 0.75% bupivacaine (another member of the amino amide class of local anesthetics) was inadvertently rapidly injected intravenously.

5.3 Intra-Articular Infusions and Risk of Chondrolysis Intra-articular infusions of local anesthetics following arthroscopic and other surgical procedures is an unapproved use, and there have been post-marketing reports of chondrolysis in patients receiving such infusions. The majority of reported cases of chondrolysis have involved the shoulder joint; cases of gleno-humeral chondrolysis have been described in pediatric and adult patients following intra-articular infusions of local anesthetics with and without epinephrine for periods of 48 to 72 hours. There is insufficient information to determine whether shorter infusion periods are not associated with these findings. The time of onset of symptoms, such as joint pain, stiffness and loss of motion can be variable, but may begin as early as the 2nd month after surgery. Currently, there is no effective treatment for chondrolysis; patients who experienced chondrolysis have required additional diagnostic and therapeutic procedures and some required arthroplasty or shoulder replacement.

5.4 Risk of Methemoglobinemia Cases of methemoglobinemia have been reported in association with local anesthetic use. Although all patients are at risk for methemoglobinemia, patients with glucose-6-phosphate dehydrogenase deficiency, congenital or idiopathic methemoglobinemia, cardiac or pulmonary compromise, infants under 6 months of age, and concurrent exposure to oxidizing agents or their metabolites are more susceptible to developing clinical manifestations of the condition. If local anesthetics must be used in these patients, close monitoring for symptoms and signs of methemoglobinemia is recommended. Signs of methemoglobinemia may occur immediately or may be delayed some hours after exposure, and are characterized by a cyanotic skin discoloration and/or abnormal coloration of the blood. Methemoglobin levels may continue to rise; therefore, immediate treatment is required to avert more serious central nervous system and cardiovascular adverse effects, including seizures, coma, arrhythmias, and death. Discontinue NAROPIN and any other oxidizing agents. Depending on the severity of the signs and symptoms, patients may respond to supportive care, i.e., oxygen therapy, hydration. A more severe clinical presentation may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen.

5.5 Central Nervous System Toxicity Careful and constant monitoring of cardiovascular and respiratory vital signs (adequacy of ventilation) and the patient's state of consciousness should be performed after each local anesthetic injection. […]

Reactions to ropivacaine are characteristic of those associated with other amide-type local anesthetics. A major cause of adverse reactions to this group of drugs may be associated with excessive plasma levels, which may be due to overdosage, unintentional intravascular injection or slow metabolic degradation. The reported adverse events are derived from clinical studies conducted in the U.S. and other countries. The reference drug was usually bupivacaine. The studies used a variety of premedications, sedatives, and surgical procedures of varying length. A total of 3,988 patients have been exposed to NAROPIN at concentrations up to 1% in clinical trials. Each patient was counted once for each type of adverse event. Because clinical trials are conducted under widely conditions, adverse reactions rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Incidence ≥ 5% For the indications of epidural administration in surgery, cesarean section, postoperative pain management, peripheral nerve block, and local infiltration, the following treatment-emergent adverse events were reported with an incidence of ≥ 5% in all clinical studies (N=3988): hypotension (37%), nausea (24.8%), vomiting (11.6%), bradycardia (9.3%), fever (9.2%), pain (8%), postoperative complications (7.1%), anemia (6.1%), paresthesia (5.6%), headache (5.1%), pruritus (5.1%), and back pain (5%). Incidence 1 to 5% Urinary retention, dizziness, rigors, hypertension, tachycardia, anxiety, oliguria, hypoesthesia, chest pain, hypokalemia, dyspnea, cramps, and urinary tract infection. Incidence in Controlled Clinical Trials The reported adverse events are derived from controlled clinical studies with NAROPIN (concentrations ranged from 0.125% to 1% for NAROPIN and 0.25% to 0.75% for bupivacaine) in the U.S. and other countries involving 3,094 patients. Table 2 and Table 3 list adverse events (number and percentage) that occurred in at least 1% of NAROPIN-treated patients in these studies. The majority of patients receiving concentrations higher than 5 mg/mL (0.5%) were treated with NAROPIN. Table 2 Adverse Events Reported in ≥1% of Adult Patients Receiving Regional or Local Anesthesia (Surgery, Labor, Cesarean Section, Postoperative Pain Management, Peripheral Nerve Block and Local Infiltration) NAROPIN total N=1661 Bupivacaine total N=1433 Adverse Reaction N % N % Hypotension 536 (32.3) 408 (28.5) Nausea 283 (17) 207 (14.4) Vomiting 117 (7) 88 (6.1) Bradycardia 96 (5.8) 73 (5.1) Headache 84 (5.1) 68 (4.7) Paresthesia 82 (4.9) 57 (4) Back pain 73 (4.4) 75 (5.2) Pain 71 (4.3) 71 (5) Pruritus 63 (3.8) 40 (2.8) Fever 61 (3.7) 37 (2.6) Dizziness 42 (2.5) 23 (1.6) Rigors (Chills) 42 (2.5) 24 (1.7) Postoperative complications 41 (2.5) 44 (3.1) Hypoesthesia 27 (1.6) 24 (1.7) Urinary retention 23 (1.4) 20 (1.4) Progression of labor poor/failed 23 (1.4) 22 (1.5) Anxiety 21 (1.3) 11 (0.8) Breast disorder, breast-feeding 21 (1.3) 12 (0.8) Rhinitis 18 (1.1) 13 (0.9) Table 3 Adverse Events Reported in ≥1% of Fetuses or Neonates of Mothers Who Received Regional Anesthesia (Cesarean Section and Labor Studies) Adverse Reaction NAROPIN total N = 639 Bupivacaine total N = 573 N % N % Fetal bradycardia 77 (12.1) 68 (11.9) Neonatal jaundice 49 (7.7) 47 (8.2) Neonatal complication-NOS 42 (6.6) 38 (6.6) Apgar score low 18 (2.8) 14 (2.4) Neonatal respiratory disorder 17 (2.7) 18 (3.1) Neonatal tachypnea 14 (2.2) 15 (2.6) Neonatal fever 13 (2) 14 (2.4) Fetal tachycardia 13 (2) 12 (2.1) Fetal distress 11 (1.7) 10 (1.7) Neonatal infection 10 (1.6) 8 (1.4) Neonatal hypoglycemia 8 (1.3) 16 (2.8) Incidence <1% The following adverse events were reported during the NAROPIN clinical program in more than one patient (N=3988), occurred at an overall incidence of <1%, and were considered relevant: Application Site Reactions – injection site pain Cardiovascular System – vasovagal reaction, syncope, postural hypotension, non-specific ECG abnormalities Female Reproductive – poor progression of labor, uterine atony Gastrointestinal System – fecal incontinence, tenesmus, neonatal vomiting General and Other Disorders – hypothermia, malaise, asthenia, accident and/or injury Hearing and Vestibular – tinnitus, hearing abnormalities Heart Rate and Rhythm – extrasystoles, non-specific arrhythmias, atrial fibrillation Liver and Biliary System – jaundice Metabolic Disorders – hypomagnesemia Musculoskeletal System – myalgia Myo/Endo/Pericardium – ST segment changes, myocardial infarction Nervous System – tremor, Horner's syndrome, paresis, dyskinesia, neuropathy, vertigo, coma, convulsion, hypokinesia, hypotonia, ptosis, stupor Psychiatric Disorders – agitation, confusion, somnolence, nervousness, amnesia, hallucination, emotional lability, insomnia, nightmares Respiratory System – bronchospasm, coughing Skin Disorders – rash, urticaria Urinary System Disorders – urinary incontinence, micturition disorder Vascular – deep vein thrombosis, phlebitis, pulmonary embolism Vision – vision abnormalities For the indication epidural anesthesia for surgery, the 15 most common adverse events were compared between different concentrations of NAROPIN and bupivacaine. Table 4 is based on data from trials in the U.S. and other countries where NAROPIN was administered as an epidural anesthetic for surgery. Table 4 Common Events (Epidural Administration) Adverse Reaction NAROPIN Bupivacaine 5 mg/mL total N=256 7.5 mg/mL total N=297 10 mg/mL total N=207 5 mg/mL total N=236 7.5 mg/mL total N=174 N (%) N (%) N (%) N (%) N (%) hypotension 99 (38.7) 146 (49.2) 113 (54.6) 91 (38.6) 89 (51.1) nausea 34 (13.3) 68 (22.9) 41 (17.4) 36 (20.7) bradycardia 29 (11.3) 58 (19.5) 40 (19.3) 32 (13.6) 25 (14.4) back pain 18 (7) 23 (7.7) 34 (16.4) 21 (8.9) 23 (13.2) vomiting 18 (7) 33 (11.1) 23 (11.1) 19 (8.1) 14 (8) headache 12 (4.7) 20 (6.7) 16 (7.7) 13 (5.5) 9 (5.2) fever 8 (3.1) 5 (1.7) 18 (8.7) 11 (4.7) chills 6 (2.3) 7 (2.4) 6 (2.9) 4 (1.7) 3 (1.7) urinary retention 5 (2) 8 (2.7) 10 (4.8) 10 (4.2) paresthesia 5 (2) 10 (3.4) 5 (2.4) 7 (3) pruritus 14 (4.7) 3 (1.4) 7 (4) Using data from the same studies, the number (%) of patients experiencing hypotension is displayed by patient age, drug and concentration in Table 5 . In Table 6 , the adverse events for NAROPIN are broken down by gender. Table 5 Effects of Age on Hypotension (Epidural Administration) Total N: NAROPIN = 760, Bupivacaine = 410 NAROPIN Bupivacaine AGE 5 mg/mL 7.5 mg/mL 10 mg/mL 5 mg/mL 7.5 mg/mL N (%) N (%) N (%) N (%) N (%) < 65 68 (32.2) 99 (43.2) 87 (51.5) 64 (33.5) 73 (48.3) ≥ 65 31 (68.9) 47 (69.1) 26 (68.4) 27 (60) 16 (69.6) Table 6 Most Common Adverse Events by Gender (Epidural Administration) Total N: Females = 405, Males = 355 Female Male Adverse Reaction N (%) N (%) hypotension 220 (54.3) 138 (38.9) nausea 119 (29.4) 23 (6.5) bradycardia 65 (16) 56 (15.8) vomiting 59 (14.6) 8 (2.3) back pain 41 (10.1) 23 (6.5) headache 33 (8.1) 17 (4.8) chills 18 (4.4) 5 (1.4) fever 16 (4) 3 (0.8) pruritus 16 (4) 1 (0.3) pain 12 (3) 4 (1.1) urinary retention 11 (2.7) 7 (2) dizziness 9 (2.2) 4 (1.1) hypoesthesia 8 (2) 2 (0.6) paresthesia 8 (2) 10 (2.8) Most common adverse reactions (incidence ≥ 5%) are hypotension, nausea, vomiting, bradycardia, fever, pain, postoperative complications, anemia, paresthesia, headache, pruritus, and back pain. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Fresenius Kabi USA, LLC at 1-800-551-7176 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch Systemic Reactions The most commonly encountered acute adverse experiences that demand immediate countermeasures are related to the central nervous system and the cardiovascular system. […]

Patients who are administered local anesthetics are at increased risk of developing methemoglobinemia when concurrently exposed to the following drugs, which could include other local anesthetics [see Warnings and Precautions ( 5.4 )] : Examples of Drugs Associated with Methemoglobinemia Class Examples Nitrates/Nitrites nitric oxide, nitroglycerin, nitroprusside, nitrous oxide Local anesthetics articaine, benzocaine, bupivacaine, lidocaine, mepivacaine, prilocaine, procaine, ropivacaine, tetracaine Antineoplastic agents cyclophosphamide, flutamide, hydroxyurea, ifosfamide, rasburicase Antibiotics dapsone, nitrofurantoin, para-aminosalicylic acid, sulfonamides Antimalarials chloroquine, primaquine Anticonvulsants Phenobarbital, phenytoin, sodium valproate Other drugs acetaminophen, metoclopramide, quinine, sulfasalazine NAROPIN should be used with caution in patients receiving other local anesthetics or agents structurally related to amide- type local anesthetics, since the toxic effects of these drugs are additive. Cytochrome P4501A2 is involved in the formation of 3-hydroxy ropivacaine, the major metabolite. In vivo, the plasma clearance of ropivacaine was reduced by 70% during coadministration of fluvoxamine (25 mg bid for 2 days), a selective and potent CYP1A2 inhibitor. Thus strong inhibitors of cytochrome P4501A2, such as fluvoxamine, given concomitantly during administration of NAROPIN, can interact with NAROPIN leading to increased ropivacaine plasma levels. Caution should be exercised when CYP1A2 inhibitors are coadministered. Possible interactions with drugs known to be metabolized by CYP1A2 via competitive inhibition such as theophylline and imipramine may also occur. Coadministration of a selective and potent inhibitor of CYP3A4, ketoconazole (100 mg bid for 2 days with ropivacaine infusion administered 1 hour after ketoconazole) caused a 15% reduction in in vivo plasma clearance of ropivacaine. Specific trials studying the interaction between ropivacaine and class III antiarrhythmic drugs (e.g., amiodarone) have not been performed, but caution is advised [see Warnings and Precautions ( 5.13 )] .

• Agents structurally related to amide-type local anesthetics: Concurrent use may cause additive effects. ( 7 )

8.1 Pregnancy Risk Summary There are no available human data on use of Naropin (ropivacaine) Injection in pregnant women to evaluate a drug-associated risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes. Local anesthetics may cause varying degrees of toxicity to the mother and fetus and adverse reactions include alterations of the central nervous system, peripheral vascular tone, and cardiac function (see Clinical Considerations ) . No teratogenicity was observed at doses up to 0.3 times the maximum recommended human dose of 770 mg/24 hours for epidural use, and equal to the MRHD of 250 mg for nerve block use, based on body surface area (BSA) comparisons and a 60 kg human weight (see Animal data ) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U. S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Labor or Delivery Local anesthetics, including ropivacaine, rapidly cross the placenta, and when used for epidural block can cause varying degrees of maternal, fetal, and neonatal toxicity [see Clinical Pharmacology ( 12 )] . The incidence and degree of toxicity depend upon the procedure performed, the type and amount of drug used, and the technique of drug administration. Adverse reactions in the parturient, fetus and neonate involve alterations of the central nervous system, peripheral vascular tone and cardiac function. Maternal Adverse reactions Maternal hypotension has resulted from regional anesthesia. Local anesthetics produce vasodilation by blocking sympathetic nerves. Therefore, during treatment of systemic toxicity, maternal hypotension or fetal bradycardia following regional block, the parturient should be maintained in the left lateral decubitus position if possible, or manual displacement of the uterus off the great vessels be accomplished. Elevating the patient's legs will also help prevent decreases in blood pressure. The fetal heart rate also should be monitored continuously, and electronic fetal monitoring is highly advisable. Data Animal data No malformations were reported in embryo-fetal development toxicity studies conducted in pregnant New Zealand white rabbits and Sprague-Dawley rats. During gestation days 6 to 18, rabbits received daily subcutaneous doses of ropivacaine at 1.3, 4.2, or 13 mg/kg/day (equivalent to 0.03, 0.10, and 0.33 times the maximum recommended human dose (MRHD) of 770 mg/24 hours, respectively, and 0.10, 0.32, and 1.0 times the MRHD of 250 mg for nerve block use, respectively based on body surface area (BSA) comparisons and a 60 kg human weight). Rats received daily subcutaneous doses of 5.3, 11, and 26 mg/kg/day (equivalent to 0.07, 0.14, and 0.33 times the MRHD for epidural use, respectively, and 0.21, 0.43, and 1.0 times the MRHD for nerve block use, respectively, based on BSA comparisons) during GD 6 to 15. No treatment-related effects on late fetal development, parturition, litter size, lactation, neonatal viability, or growth of the offspring were reported in a prenatal and postnatal reproductive and development toxicity study; however functional endpoints were not evaluated. Female rats were dosed daily subcutaneously from GD 15 to Lactation Day 20 at doses of 5.3, 11,and 26 mg/kg/day (equivalent to 0.07, 0.1, and 0.3 times the MRHD for epidural use, respectively, and 0.21, 0.43, and 1.0 times the MRHD for nerve block use, respectively), with maternal toxicity exhibited at the high dose. No adverse effects in physical developmental milestones or in behavioral tests were reported in a 2-generational reproduction study, in which rats received daily subcutaneous doses of 6.3, 12, and 23 mg/kg/day (equivalent to 0.08, 0.15, and 0.29 times the MRHD for epidural use, respectively, and 0.24, 0.45, and 0.88 times the MRHD for nerve block use, respectively, based on BSA comparisons) for 9 weeks before mating and during mating for males, and for 2 weeks before mating and during mating, pregnancy, and lactation, up to day 42 post coitus for females. Significant pup loss was observed in the high dose group during the first 3 days postpartum, from a few hours up to 3 days after delivery compared to the control group, which was considered secondary to impaired maternal care due to maternal toxicity. No differences were observed in litter parameters, or fertility, mean gestation time, or number of live births were observed between the control (saline) and treatment groups [see Carcinogenesis, Mutagenesis, Impairment of Fertility ( 13.1 )] .

8.2 Lactation Risk Summary One publication reported that ropivacaine is present in human milk at low levels following administration of ropivacaine in women undergoing cesarean section. No adverse reactions were reported in the infants. There is no available information on the drug's effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for NAROPIN and any potential adverse effects on the breastfed child from NAROPIN or from the underlying maternal condition.

8.4 Pediatric Use The safety and efficacy of NAROPIN in pediatric patients have not been established.

8.5 Geriatric Use Of the 2,978 subjects that were administered NAROPIN Injection in 71 controlled and uncontrolled clinical studies, 803 patients (27%) were 65 years of age or older which includes 127 patients (4%) 75 years of age and over. NAROPIN Injection was found to be safe and effective in the patients in these studies. Clinical data in one published article indicate that differences in various pharmacodynamic measures were observed with increasing age. In one study, the upper level of analgesia increased with age, the maximum decrease of mean arterial pressure (MAP) declined with age during the first hour after epidural administration, and the intensity of motor blockade increased with age. This drug and its metabolites are known to be excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Elderly patients are more likely to have decreased hepatic, renal, or cardiac function, as well as concomitant disease. Therefore, care should be taken in dose selection, starting at the low end of the dosage range, and it may be useful to monitor renal function [see Clinical Pharmacology ( 12.3 )] .

8.6 Hepatic Impairment Because amide-type local anesthetics such as ropivacaine are metabolized by the liver, these drugs, especially repeat doses, should be used cautiously in patients with hepatic disease. Patients with severe hepatic disease, because of their inability to metabolize local anesthetics normally, are at a greater risk of developing toxic plasma concentrations [see Warning and Precautions ( 5.11 )].

8.7 Renal Impairment This drug and its metabolites are known to be excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Therefore, care should be taken in dose selection, starting at the low end of the dosage range, and it may be useful to monitor renal function [see Clinical Pharmacology ( 12.3 )] .

Ropivacaine is a member of the amino amide class of local anesthetics and is supplied as the pure S-(-)-enantiomer. Local anesthetics block the generation and the conduction of nerve impulses, presumably by increasing the threshold for electrical excitation in the nerve, by slowing the propagation of the nerve impulse, and by reducing the rate of rise of the action potential. In general, the progression of anesthesia is related to the diameter, myelination and conduction velocity of affected nerve fibers. Clinically, the order of loss of nerve function is as follows: (1) pain, (2) temperature, (3) touch, (4) proprioception, and (5) skeletal muscle tone.