Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.
Naropin (Astra Pharmaceuticals)
ampoules containing 2 mg/mL, 7.5 mg/mL and 10 mg/mL
2 mg/mL in 100 mL and 200 mL infusion bags
Ropivacaine is a local anaesthetic with a similar structure to bupivacaine. The drug has been approved for epidural blocks, field blocks and major nerve blocks. It can be used in surgery, during labour and for postoperative pain.
At high doses, ropivacaine produces surgical anaesthesia, while lower doses cause a sensory block. These effects begin within a few minutes and last for 2-6 hours when ropivacaine is used for field blocks. The onset is similar when the drug is used for lumbar epidural anaesthesia, but the duration is shorter. Ropivacaine is extensively metabolised, so it is not recommended for patients with hepatic dysfunction.
The adverse effects of ropivacaine are similar to those of bupivacaine and include hypotension, bradycardia, nausea and vomiting. There is some evidence from animal studies that ropivacaine has less central nervous system and cardiovascular toxicity than bupivacaine. Acute systemic toxicity can cause convulsions, apnoea and cardiac arrest.