BUPIVACAINE HYDROCHLORIDE

Great care must be taken in order to prevent an accidental intravascular injection, always including careful aspirations. For epidural anaesthesia, a test dose of 3 - 5ml of bupivacaine containing adrenaline should be administered, since an intravascular injection of adrenaline will be quickly recognised by an increase in heart rate.

Verbal contact and frequent measurements of the heart rate, preferably by electrographic (ECG) monitoring, should be maintained throughout a period of 5 minutes following the test dose. Aspiration should be repeated prior to the administration of the total dose.

, in incremental doses under constant contact with the patient. If mild toxic symptoms develop, the injection must be immediately stopped. The lowest dosage required to achieve effective anaesthesia should be given. However, the dose will vary, and will be dependent on the area to be anaesthetised, the vascularity of the tissues, the number of neuronal segments to be blocked, individual tolerance and the technique of anaesthesia used.

For most indications, the duration of anaesthesia with bupivacaine solutions is such that a single dose is sufficient. The maximum dosage must be determined by evaluating the size and physical status of the patient and considering the usual rate of systemic absorption from a particular injection site.

Experience to date indicates a single dose of up to 150mg bupivacaine hydrochloride. Doses of up to 50mg 2-hourly may subsequently be used. The dosages in the following table are recommended as a guide for use in the average adult. For young, elderly or debilitated patients, these doses should be reduced.

5 2 to 4 10 to 20 + With continuous (intermittent) techniques, repeat doses increase the degree of motor block. 5% may produce complete motor block for intra-abdominal surgery. * Bupivacaine without adrenaline. 4ml maximum dose.

Paediatric population:

Paediatric patients 1 to 12 years of age Paediatric regional anaesthetic procedures should be performed by qualified clinicians who are familiar with this population and the technique. The doses in the table should be regarded as guidelines for use in paediatrics.

Individual variations occur. In children with a high body weight a gradual reduction of the dosage is often necessary and should be based on the ideal body weight. Standard textbooks should be consulted for factors affecting specific block techniques and for individual patient requirements.

The lowest dose required for adequate analgesia should be used. Conc. 0
) a)The onset and duration of peripheral nerve blocks depend on the type of block and the dose administered. b)Thoracic epidural blocks need to be given by incremental dosage until the desired level of anaesthesia is achieved.

In children the dosage should be calculated on a weight basis up to 2 mg/kg. In order to avoid intravascular injection, aspiration should be repeated prior to and during administration of the main dose. This should be injected slowly in incremental doses, particularly in the lumbar and thoracic epidural routes, constantly and closely observing the patient’s vital functions.

5mg per tonsil. 25 mg/kg. 25-2 mg/kg. 5 mg/kg. 5%w/v solution for Injection in children < 1 year of age have not been established. Only limited data are available. Safety and efficacy of intermittent epidural bolus injection or continuous infusion have not been established.

Only limited data is available.

Accidental sub-arachnoid injection can lead to very high spinal anaesthesia possibly with apnoea and severe hypotension. The adverse reaction profile for Bupivacaine hydrochloride is similar to those for other long acting local anaesthetics.

, epidural abscess) by needle puncture. Neurological damage is a rare but well recognised consequence of regional and particularly epidural and spinal anaesthesia. g. direct injury to the spinal cord or spinal nerves, anterior spinal artery syndrome, injection of an irritant substance, or an injection of a non-sterile solution.

These may result in localised areas of paraesthesia or anaesthesia, motor weakness, loss of sphincter control and paraplegia. Occasionally these are permanent. The adverse reactions considered at least possibly related to treatment with Bupivacaine hydrochloride from clinical trials with related products and post- marketing experience are listed below by body system organ class and absolute frequency.

Frequencies are defined as very common (1/10), common (1/100, < 1/10), uncommon (1/1,000, < 1/100), rare (1/10,000, < 1/1,000), including isolated reports, or not known (identified through post-marketing safety surveillance and the frequency cannot be estimated from the available data).

4) Nervous system disorders Common paraesthesia, dizziness Following epidural injection of some local anaesthetic agents including bupivacaine, high sympathetic blockade may occasionally result in ocular and other symptoms similar to those seen in Horner’s syndrome.

These effects are encountered more commonly in pregnant women. 5) Respiratory disorders Rare Respiratory depression Gastrointestinal disorders Very Common Nausea Common Vomiting Renal and Urinary Common Urinary retention Hepatic dysfunction, with reversible increases of SGOT, SGPT, alkaline phosphatase and bilirubin, have been observed following repeated injections or long-term infusions of bupivacaine.

If signs of hepatic dysfunction are observed during treatment with bupivacaine, the drug should be discontinued. Paediatric population Adverse drug reactions in children are similar to those in adults, however, in children, early signs of local anaesthetic toxicity may be difficult to detect in cases where the block is given during sedation or general anaesthesia.

1 Acute systemic toxicity Systemic toxic reactions primarily involve the central nervous system (CNS) and the cardiovascular system. 4). CNS reactions are similar for all amide local anaesthetics, while cardiac reactions are more dependent on the drug, both quantitatively and qualitatively.

Central nervous system toxicity is a graded response with symptoms and signs of escalating severity. The first symptoms are usually light-headedness, circumoral paraesthesia, numbness of the tongue, hyperacusis, tinnitus and visual disturbances.

Dysarthria, muscular twitching or tremors are more serious and precede the onset of generalised convulsions. These signs must not be mistaken for neurotic behaviour. Unconsciousness and grand mal convulsions may follow, which may last from a few seconds to several minutes.

Hypoxia and hypercarbia occur rapidly following convulsions due to the increased muscular activity, together with the interference with respiration and possible loss of functional airways. In severe cases apnoea may occur. Acidosis, hyperkalaemia and hypoxia increase and extend the toxic effects of local anaesthetics.

Recovery is due to redistribution of the local anaesthetic drug from the central nervous system and subsequent metabolism and excretion. Recovery may be rapid unless large amounts of the drug have been injected. Cardiovascular system toxicity may be seen in severe cases and is generally preceded by signs of toxicity in the central nervous system.

In patients under heavy sedation or receiving a general anaesthetic, prodromal CNS symptoms may be absent. Hypotension, bradycardia, arrhythmia and even cardiac arrest may occur as a result of high systemic concentrations of local anaesthetics, but in rare cases cardiac arrest has occurred without prodromal CNS effects.

2 Treatment of acute toxicity If signs of acute systemic toxicity appear, injection of the local anaesthetic should be immediately stopped. Treatment of a patient with systemic toxicity consists of arresting convulsions and ensuring adequate ventilation with oxygen, if necessary by assisted or controlled ventilation (respiration).

Once convulsions have been controlled and adequate ventilation of the lungs ensured, no other treatment is generally required. If circulatory arrest should occur, immediate cardiopulmonary resuscitation should be instituted. Optimal oxygenation and ventilation and circulatory support as well as treatment […]

There have been reports of cardiac arrest during the use of bupivacaine for epidural anaesthesia. or peripheral nerve blockade where resuscitative efforts have been difficult, and were required to be prolonged before the patient responded.

However, in some instances resuscitation has proven impossible despite apparently adequate preparation and appropriate management. Like all local anaesthetic drugs, bupivacaine may cause acute toxicity effects on the central nervous and cardiovascular systems if utilised for local anaesthetic procedures resulting in high blood concentrations of the drug.

This is especially the case after unintentional intravascular administration or injection into highly vascular areas. Ventricular arrhythmia, ventricular fibrillation, sudden cardiovascular collapse and death have been reported in connection with high systemic concentrations of bupivacaine.

Adequate resuscitation equipment should be available whenever local or general anaesthesia is administered. 2). Before any nerve block is attempted, intravenous access for resuscitation purposes should be established. 8).

Note:

No specific contraindications were identified for paediatric patients. Major peripheral nerve blocks may require the administration of a large volume of local anaesthetic in areas of high vascularity, often close to large vessels where there is an increased risk of intravascular injection and/or systemic absorption.

This may lead to high plasma concentrations. Overdosage or accidental intravenous injection may give rise to toxic reactions. Injection of repeated doses of bupivacaine hydrochloride may cause significant increases in blood levels with each repeated dose due to slow accumulation of the drug.

Tolerance varies with the status of the patient. Although regional anaesthesia is frequently the optimal anaesthetic technique, some patients require special attention in order to reduce the risk of dangerous side effects: • The elderly and patients in poor general condition should be given reduced doses commensurate with their physical status.

• Patients with partial or complete heart block – due to the fact that local anaesthetics may depress myocardial conduction • Patients with advanced liver disease or severe renal dysfunction. g. amiodarone) should be under close surveillance and ECG monitoring, since cardiac effects may be additive.

Only in rare cases have amide local anaesthetics been associated with allergic reactions (with anaphylactic shock developing in most severe instances). Patients allergic to ester-type local anaesthetics drugs ( procaine , tetracaine, benzocaine, etc) have not shown cross-sensitivity to agents of the amide-type such as bupivacaine.

Certain local anaesthetic procedures may be associated with serious adverse reactions, regardless of the local anaesthetic drug used. • Local anaesthetics should be used with caution for epidural anaesthesia in patients with impaired cardiovascular function since they may be less able to compensate for functional changes associated with the prolongation of A-V conduction produced by these drugs.

• The physiological effects generated by a central neural blockade are more pronounced in the presence of hypotension. Patients with hypovolaemia due to any cause can develop sudden and severe hypotension during epidural anaesthesia.

Epidural anaesthesia should therefore be avoided or used with caution in patients with untreated hypovolaemia or significantly impaired venous return. • Retrobulbar injections may very rarely reach the cranial subarachnoid space causing temporary blindness, cardiovascular collapse, apnoea, convulsions etc.

• Retro- and peribulbar injections of local anaesthetics carry a low risk of persistent ocular muscle dysfunction. The primary causes include trauma and/or local toxic effects on muscles and/or nerves. The severity of such tissue reactions is related to the degree of trauma, the concentration of the local anaesthetic and the duration of exposure of the tissue to the local anaesthetic.

For this reason, as with all local anaesthetics, the lowest effective concentration and dose of local anaesthetic should be used. • Vasoconstrictors may aggravate tissue reactions and should be used only when indicated. • Small doses of local anaesthetics injected into the head and neck, including retrobulbar, dental and stellate ganglion blocks, may produce systemic toxicity due to inadvertent intra-arterial injection.

• Paracervical block may have a greater adverse effect on the foetus, than other nerve blocks used in obstetrics. Due to the systemic toxicity of bupivacaine, special care should be taken when using bupivacaine for paracervical block.

• There have been post-marketing reports of chondrolysis in patients receiving post-operative intra-articular continuous infusion of local anaesthetics. The majority of reported cases of chondrolysis have involved the shoulder joint.

Due to multiple contributing factors and inconsistency in the scientific literature regarding mechanism of action, causality has not been established. Intra-articular continuous infusion is not an approved indication for Bupivacaine.

Local anaesthetics should be used with caution for epidural or spinal anaesthesia in the following situations: marked obesity, senility, cerebral atheroma, myocardial degeneration and toxaemia. Epidural and spinal anaesthesia with any local anaesthetic can cause hypotension and bradycardia which should be anticipated and appropriate precautions taken.

These may include preloading the circulation […]

Bupivacaine hydrochloride solutions are contraindicated in patients with a known hypersensitivity to local anaesthetic agents of the amide group or to other components of the injectable formulation. Solutions of bupivacaine hydrochloride are contraindicated for intravenous regional anaesthesia (Bier's block).

Epidural anaesthesia, regardless of the local anaesthetic used, has its own contraindications which include: Active disease of the central nervous system such as meningitis, poliomyelitis, intracranial haemorrhage, subacute combined degeneration of the cord due to pernicious anaemia, and cerebral or spinal tumours.

Tuberculosis of the spine. Pyogenic infection of the skin at or adjacent to the site of lumbar puncture. Cardiogenic or hypovolaemic shock. Coagulation disorders or ongoing anticoagulant therapy. Epidural and spinal anaesthesia is contraindicated in patients with an expanding cerebral lesion, a tumour, cyst or abscess, which may, if the intracranial pressure is suddenly altered, cause obstruction to the cerebrospinal fluid or blood circulation (the pressure cone).

g. penile block, Oberst block) may cause ischemic tissue necrosis.