WHO Model Prescribing Information: Drugs Used in Anaesthesia
(1989; 60 pages) [French] Ver el documento en el formato PDF
Índice de contenido
Ver el documentoPreface
Ver el documentoIntroduction
Abrir esta carpeta y ver su contenidoPremedication
Abrir esta carpeta y ver su contenidoGeneral anaesthetics and oxygen
Cerrar esta carpetaLocal anaesthetics
Ver el documentoBupivacaine
Ver el documentoLidocaine
Ver el documentoTetracaine
Ver el documentoEpinephrine (for use with local anaesthetics)
Abrir esta carpeta y ver su contenidoNon-opioid analgesics
Abrir esta carpeta y ver su contenidoOpioid analgesics and antagonists
Abrir esta carpeta y ver su contenidoMuscle relaxants and cholinesterase inhibitors
Abrir esta carpeta y ver su contenidoBlood substitutes
Abrir esta carpeta y ver su contenidoSolutions for correcting water and electrolyte imbalance
Abrir esta carpeta y ver su contenidoAntacid for use in obstetric practice
Ver el documentoAnaesthesia at the District Hospital
Ver el documentoSelected WHO publications of related interest
Ver el documentoBack cover
 

Bupivacaine

Group: local anaesthetic agent
Injection (hydrochloride): 2.5 mg/ml (0.25%) or 5 mg/ml (0.5%) in 10-ml ampoule; 5 mg/ml (0.5%) in 1.8-ml cartridge for dental anaesthesia; 7.5 mg/ml (0.75%) with glucose 82.5 mg/ml (8.25%) in 4-ml ampoule

General information

Bupivacaine is a long-acting local anaesthetic. Addition of epinephrine is thus rarely required. It blocks initiation and transmission of nerve impulses at the site of application by stabilizing the neuronal membrane. The compound is ultimately metabolized in the liver. Depending upon the site of injection and the concentration used, anaesthesia usually lasts 2-4 hours.

Clinical information

Uses

• Infiltration anaesthesia.
• Peripheral and sympathetic nerve block.
• Dental anaesthesia.
• Spinal anaesthesia.
• Epidural and caudal anaesthesia (these techniques produce prolonged regional anaesthesia, and should be attempted only by experienced specialist anaesthetists).

Bupivacaine is unsuitable for intravenous regional anaesthesia or for topical application.

Dosage and administration

The aim is to administer the smallest effective dose. This varies with the procedure adopted, the degree of anaesthesia required, the rate of absorption from the injection site and the size and responsive-ness of the patient. Higher initial blood levels are attained with more concentrated solutions.

The maximum cumulative safe dose for adults and children of a 0.25% solution of bupivacaine is 1.5 mg/kg. The table provides a general guide to dosage in adults. Smaller dosages should be administered to debilitated, elderly, epileptic and acutely ill patients.

Bupivacaine is generally not recommended for children aged less than 12 years since there is insufficient information on the effects of its use in this age group.

Solutions containing preservatives should not be used for spinal, epidural or caudal anaesthesia.

Spinal anaesthesia

Spinal anaesthesia should be attempted only by a person fully trained in the technique and competent to treat possible complications. A “heavy” solution (0.75% bupivacaine in 8.25% glucose) will provide the muscular relaxation required for abdominal surgery. Full aseptic technique must be employed for the injection and the patient must be appropriately tilted to ensure safety and the required level of analgesia.

Anaesthetic procedure

Concentration (%)

Dose

   

ml

mg

Local infiltration

0.25

up to 60

up to 150

Peripheral nerve block

0.5

up to 30

up to 150

Dental anaesthesia

0.5

1.8-3.6

9.0-18.0

Spinal anaesthesia

0.75 (+ 8.25% glucose)

1-1.5

7.5-11.25

Spinal anaesthesia always causes hypotension as a result of sympathetic blockade. It should never be used in patients with any condition resulting in hypovolaemia. The hypotensive response may largely be averted by preliminary intravenous infusion of 500-1000 ml of physiological saline (9 mg/ml) but blood pressure should always be measured every 2 minutes for at least 10 minutes. Postoperative headache can be prevented by instructing the patient to remain supine for 24 hours.

Obstetric practice

Lumbar epidural block has largely replaced caudal epidural block for relief of pain in labour. It requires less local anaesthetic, carries less risk of infection and is readily extended should caesarean section become necessary. However, because of the risk to both the mother and the fetus, it should be attempted only by an experienced specialist anaesthetist. Concentrations of bupivacaine greater than 0.5% are contraindicated for this purpose in view of reports of cardiac arrest and maternal death. Maternal blood pressure, fetal heart rate and uterine contractions should be monitored throughout the procedure. Paracervical block is no longer recommended during labour because it results in very high levels of the drug in fetal blood.

Contraindications

• Known or suspected hypersensitivity to bupivacaine.

• Skin infection adjacent to the intended site of injection, concomitant anticoagulant therapy or an abnormal bleeding tendency.

• Severe anaemia or heart disease.

• Spinal and epidural anaesthetics should never be administered to dehydrated or hypovolaemic patients.

Precautions

Facilities and equipment for resuscitation should be readily available at all times.

Assurance must be obtained that the patient is psychologically prepared to accept the proposed procedure.

High blood levels of bupivacaine must be avoided in patients with hepatic impairment.

Care must always be taken to avoid inadvertent intravascular injection.

Use in pregnancy

Safe use in early pregnancy has not been established. However, there is no clinical evidence to suggest that exposure of the mother to bupivacaine is harmful to the fetus.

Adverse effects

These may result from excessive dosage, inadvertent intravascular injection, or injection into highly vascular tissues. Initial signs of light-headedness, dizziness, blurred vision, restlessness, tremors and, occasionally, convulsions are rapidly followed by drowsiness, unconsciousness and respiratory failure. Myocardial depression and hypotension can result in hypoxia, acidosis, heart block and cardiac arrest.

Hypersensitivity and allergic reactions may also occur.

Epidural anaesthesia is occasionally complicated by urinary retention, faecal incontinence, headache, backache or loss of perineal sensation. Transient paraesthesiae and paraplegia are very rare complications.

Drug interactions

Co-administration of oxytocic drugs post-partum may cause severe and prolonged hypertension. The use of bupivacaine preparations containing epinephrine during or following the administration of halothane or trichloroethylene creates a risk of cardiac dysrhythmias.

Overdosage

Overdosage or accidental intravascular injection is characterized by the systemic effects described above. Treatment is symptomatic. There is no specific anti dote. A clear airway should be maintained and ventilation assisted as required. Convulsions may be controlled by diazepam or thiopental.

Storage

Bupivacaine injection should be kept protected from light and should not be allowed to freeze. Ampoules should not be used if the solution is discoloured.

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