Bupivacaine

Bupivacaine is a local anaesthetic drug belonging to the amino amide group. It is commonly marketed by AstraZeneca under various trade names including Marcain, Marcaine and Sensorcaine.

Clinical use

Indications

Bupivacaine is indicated for local anaesthesia including infiltration, nerve block, epidural and intrathecal anaesthesia. Bupivacaine is often administered by epidural injection prior to total hip arthroplasty. It is also commonly injected into surgical wound sites to reduce pain for up to 20 hours after surgery.

Bupivacaine is sometimes co-administered with adrenaline to prolong the duration of action, fentanyl for epidural analgesia, or glucose.

Contraindications

Bupivacaine is contraindicated for IV regional anaesthesia (IVRA).

Adverse effects

Compared to other local anaesthetics, bupivacaine is markedly cardiotoxic. However, adverse drug reactions (ADRs) are rare when it is administered correctly. Most ADRs relate to administration technique (resulting in systemic exposure) or pharmacological effects of anaesthesia, however allergic reactions can rarely occur.

Systemic exposure to excessive quantities of bupivacaine mainly result in central nervous system (CNS) and cardiovascular effects – CNS effects usually occur at lower plasma concentrations and additional cardiovascular effects present at higher concentrations, though cardiovascular collapse may also occur with low concentrations. CNS effects may include CNS excitation (nervousness, tingling around the mouth, tinnitus, tremor, dizziness, blurred vision, seizures) followed by depression (drowsiness, loss of consciousness, respiratory depression and apnoea). Cardiovascular effects include hypotension, bradycardia, arrhythmias, and/or cardiac arrest – some of which may be due to hypoxemia secondary to respiratory depression.

Treatment of overdose

There is evidence that Intralipid, a commonly available intravenous lipid emulsion, can be effective in treating severe cardiotoxicity secondary to local anaesthetic overdose, including human case reports of successful use in this way.

Developments

Levobupivacaine is the S-enantiomer of bupivacaine, with a longer duration of action and produces less vasodilation. Durect Corporation is developing a biodegradable controlled-release drug delibery system for post surgery. It is currently in Phase II.

© Medic8 ® All Rights Reserved.