Bunascan Dosage/Direction for Use

As with all local anaesthetics, the dosage varies and depends upon the area to be anaesthetised, the vascularity of the tissue, the number of neuronal segments to be blocked, the depth of anaesthesia and degree of muscle relaxation required, individual tolerance, the technique of anaesthesia, and the physical condition of patient. The lowest dosage that results in effective anaesthesia should be used. In general, surgical anaesthesia requires the use of higher concentrations and doses than those required for analgesia. The volume of the drug used will affect the extent of spread of anaesthesia. The presentations of Bunascan 0.5% injection solutions are intended for single use only. Any solution remaining from an opened container should be discarded.
The following tables are a guide to dosage. The clinician's experience and knowledge of the patient's physical status are of importance in deciding the dose. Experience to date indicates that 400 mg administered over 24 hours is well tolerated in average adults. Dosage recommendations for Bunascan 0.5% solutions for various anaesthetic procedures in an average, healthy 70 kg adult patient.


Click on icon to see table/diagram/image




Click on icon to see table/diagram/image


NOTE: Recommended doses: Tolerability varies widely between patients and toxic effects may occur after any local anaesthetic procedure. Careful observation of the patient must therefore be maintained. It is recommended that the dose of bupivacaine at any time should not exceed 2 mg/kg (both plain and adrenaline­-containing solutions). However, the dose administered must be tailored to the individual patient and procedure, and the maximum dose quoted here should be used as a guide only.
Injection: Injection of repeated doses of bupivacaine may cause significant increase in blood levels with each repeated dose, due to accumulation of the drug or its metabolites, or due to slow metabolic degradation.
The rapid injection of a large volume of local anaesthetic solution should be avoided and fractional doses should be used when feasible. For most indications the duration of Bunascan 0.5% is such that a single dose is sufficient.
Hypotension: During thoracic, lumbar and caudal epidural anaesthesia/analgesia, a marked fall in blood pressure and/or intercostals paralysis may be seen, possibly due to the use of excessive doses, improper positioning of the patient or accidental disposition of the anaesthetic within the subarachnoid space. Hypotension and bradycardia may occur as a result of sympathetic blockade.
Test Dose: For epidural anaesthesia, a test dose of 3-5 mL of a local anaesthetic solution, preferably containing up to 15 micrograms of adrenaline, (e.g. 3 mL BUNASCAN 0.5% with adrenaline 1:200,000) should be administered. Verbal contact and repeated monitoring of heart rate and blood pressure should be maintained for 5 minutes following the test dose after which, in the absence of signs of subarachnoid or intravascular injection, the main dose may be given. Use of a test dose containing adrenaline may have further advantages in that an intravascular injection of adrenaline will be quickly recognized by an increase in heart rate, usually within about 40 seconds. To detect this, the heart rate and rhythm should be monitored with an electrocardiogram. An accidental intrathecal injection may be recognized by signs of a spinal block.
Prior to administration of the total dose, aspiration should be repeated. The main dose should be injected slowly at a rate of 25-50 mg/min while closely observing the patient's vital functions and maintaining verbal contact. If toxic symptoms or sign occur, the injection should be stopped immediately.
Use in Children: Experience with bupivacaine in children under the age of 12 is limited. The dosage in children should be calculated on a weight loss basis up to 2 mg/kg. The addition of adrenaline will prolong the duration of the block by 50-100%.
Use in Debilitated or Elderly Patients: Debilitated or elderly patients, including those with partial or complete heart block, advanced liver disease or severe renal dysfunction should be given a reduced dosage commensurate with their physical condition.