- LOCAL ANAESTHEITICS
- Pharmaceutical Form : ٍSolutions
- Composition : Lidocain Hcl 10 mg / 1 ml
- Active Substance : Lidocain Hcl
Lidocaine is absorbed from injection sites including muscle.
Lidocaine is bound to plasma proteins
The drug crosses the blood-brain and placental barriers
Lidocaine is metabolised in the liver
Further metabolism occurs and metabolites are excreted in the urine with less than 10% as unchanged lidocaine. The elimination half-life of lidocaine following an intravenous bolus injection is one to two hours, but this may be prolonged in patients with hepatic dysfunction.
Lidocaine is a local anaesthetic of the amide group. Lidocaine Hydrochloride Injection BP is for use in infiltration anaesthesia, intravenous regional anaesthesia and nerve blocks.
Known hypersensitivity to anaesthetics of the amide type.
- Complete heart block
Lidocaine should only be used by people with skills in resuscitation.
Facilities and equipment for resuscitation should be available when administering local anaesthetics.
As with other local anaesthetics, lidocaine should be used with caution in patients with epilepsy, myasthenia gravis, congestive cardiac failure, bradycardia or respiratory depression, including agents known to interact with Lidocaine either to increase its availability or additive effects e.g. phenytoin or prolong its elimination e.g. hepatic or end renal insufficiency where the metabolites of Lidocaine may accumulate.
The effect of local anaesthetics may be reduced if the injection is made into an inflamed or infected area.
Intramuscular Lidocaine may increase creatinine phosphokinase concentrations which can interfere with the diagnosis of acute myocardial infarction. Lidocaine has been shown to be porphyrinogenic in animals and should be avoided in persons suffering from porphyria.
Hypokalaemia, hypoxia and disorder of acid-base balance should be corrected before treatment with intravenous lidocaine begins.
Central nerve blocks may cause cardiovascular depression, especially in the presence of hypovolaemia, and therefore epidural anaesthesia should be used with caution in patients with impaired cardiovascular function.
Paracervical block can sometimes cause foetal bradycardia or tachycardia and careful monitoring of foetal heart rate is necessary.
Injections in the head and neck region may be made inadvertently into an artery causing cerebral symptoms even at low doses.
Retrobulbar injections may rarely reach the cranial subarachnoid space, causing serious/severe reactions including cardiovascular collapse, apnoea, convulsions and temporary blindness.
Retro- and peribulbar injections of local anaesthetics carry a low risk of persistent ocular motor 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 local anaesthetic. For this reason, the lowest effective concentration and dose of local anaesthetic should be used.
Lidocaine Injection is not recommended for use in neonates. The optimum serum concentration of lidocaine required to avoid toxicity, such as convulsions and cardiac arrhythmias, in this age group is not known.
Although animal studies have revealed no evidence of harm to the foetus, lidocaine crosses the placenta and should not be administered during early pregnancy unless the benefits are considered to outweigh the risks.
Lidocaine readily crosses the placental barrier after epidural or intravenous administration to the mother.
Small amounts of lidocaine are secreted into breast milk and the possibility of an allergic reaction in the infant should be borne in mind when using lidocaine in nursing mothers.
Effects on Ability to Drive and Use Machines
Where anaesthesia affects areas of the body involved in driving or operating machinery, patients should be advised to avoid these activities until normal function is fully restored.
In common with other local anaesthetics, adverse reactions to lidocaine are rare and are usually the result of raised plasma concentrations due to accidental intravascular injection, excessive dosage or rapid absorption from highly vascular areas, or may result from a hypersensitivity, idiosyncrasy or diminished tolerance on the part of the patient. Systemic toxicity mainly involves the central nervous system and/or the cardiovascular system
Immune system disorders:
Hypersensitivity reactions (allergic or anaphylactoid reactions, anaphylactic shock)
Skin testing for allergy to Lidocaine is not considered to be reliable.
Nervous & Psychiatric disorders:
Neurological signs of systemic toxicity include dizziness or light-headedness, nervousness, tremor, circumoral paraesthesia, tongue numbness, drowsiness, convulsions, coma.
Blurred vision, diplopia and transient amaurosis may be signs of lidocaine toxicity.
Bilateral amaurosis may also be a consequence of accidental injection of the optic nerve sheath during ocular procedures. Orbital inflammation and diplopia have been reported following retro- or peribulbar anaesthesia.
Ear and labyrinth disorders:
Cardiac and vascular disorders:
Cardiovascular reactions are depressant and may manifest as hypotension, bradycardia, myocardial depression, cardiac arrhythmias and possibly cardiac arrest or circulatory collapse.
Respiratory, thoracic or mediastinal disorders:
Dyspnoea, bronchospasm, respiratory depression, respiratory arrest.
Skin & subcutaneous tissue disorders:
Rash, urticaria, angioedema, face oedema.
While adrenaline when used in conjunction with Lidocaine might decrease vascular absorption, it greatly increases the danger of ventricular tachycardia and fibrillation if accidentally injected intravenously.
Dopamine and 5 hydroxytryptamine reduce the convulsant threshold to Lidocaine.
Narcotics are probably proconvulsants and this would support the evidence that Lidocaine reduces the seizure threshold to fentanyl in man.
Opioid-antiemetic combination sometimes used for sedation in children could reduce the convulsant threshold to Lidocaine and increase the CNS depressant effect.
Cimetidine and propranolol depress microsomal enzyme activity, thus enhancing lidocaine toxicity if concomitantly administered with these drugs, requiring a reduction in the dosage of Lidocaine.
Ranitidine produces a small reduction in renal clearance. Increase in serum levels of Lidocaine may also occur with anti-viral agents (e.g. amprenavir, atazanavir, darunavir, lopinavir).
Hypokalemia caused by diuretics may antagonize the action of lidocaine if administered concomitantly.
Cardiovascular collapse has been reported following the use of bupivacaine in patients on treatment with verapamil and timolol; Lidocaine is closely related to bupivacaine.
Lidocaine should be used with caution in patients receiving other local anaesthetics or agents related structurally to amide-type local anaesthetics (e.g. anti-arrhythmics, such as mexiletine), since the systemic toxic effects are additive. Specific interaction studies with lidocaine and class III anti-arrhythmic drugs (e.g. amiodarone) have not been performed, but caution is advised.
There may be an increased risk of ventricular arrhythmia in patients treated concurrently with antipsychotics which prolong or may prolong the QT interval (e.g. pimozide, sertindole, olanzapine, quetiapine, zotepine), prenylamine, adrenaline (if accidently injected intravenously) or 5HT3 antagonists (e.g. tropisetron, dolasetron) Concomitant use of quinupristin/dalfopristin may increase lidocaine levels with a subsequent increased risk of ventricular arrhythmias and therefore should be avoided.
There may be an increased risk of enhanced and prolonged neuromuscular blockade in patients treated concurrently with muscle relaxants (e.g. suxamethonium
DOSES / INDICATIONS
The method of administration of lidocaine varies according to the procedure (infiltration anaesthesia, intravenous regional anaesthesia or nerve block).
The dosage should be adjusted according to the response of the patient and the site of administration. The lowest concentration and smallest dose producing the required effect should be given.
The following table is intended as a guide to the concentrations, volumes and doses of Lidocaine Hydrochloride Injection BP for various types of anaesthetic procedure in healthy adults.
Elderly or debilitated patients require smaller doses commensurate with age and physical status.
|Type of block||Conc.
|Peripheral nerves (upper limb)||10||10-1||100-10|
|3 in 1||15-10||30|
|Inguinal Field Block||5|
|Intravenous regional anaesthesia||5||40-10||200-50|
Children: A 1% or 2% solution may be used and the maximum dose should not exceed 5mg/kg (plain) or 7mg/kg [with adrenaline (epinephrine)].
Symptoms of acute systemic toxicity:
Central nervous system toxicity presents with symptoms of increasing severity. Patients may present initially with circumoral paraesthesia, numbness of the tongue, light-headedness, and tinnitus. Visual disturbances and muscular tremors or muscle twitching are more serious and precede the onset of generalized convulsions.
Unconsciousness and convulsions may usually follow, which may last from a few second to several minutes.
Hypoxia and hypercapnia occur rapidly following convulsions due to increase muscular activity, together with the interference with normal respiration and loss of the airway.
In severe cases, apnoea may occur. Acidosis increases the toxic effects of local anaesthetics.
Effects on the cardiovascular system may be seen in severe cases.
Hypotension, bradycardia, arrhythmia and cardiac arrest may occur as a result of high systemic concentrations, with potentially fatal outcome.
Recovery occurs as a consequence of redistribution of the local anaesthetic drug from the central nervous system and metabolism and may be rapid unless large amounts of the drug have been injected.
Treatment of acute toxicity
If signs of acute systemic toxicity appear, injection of the anaesthetic should be stopped immediately.
Treatment will be required if convulsions and CNS depression occurs.
Dialysis is of negligible value in the treatment of acute overdosage with lidocaine.
Do not store above 25°C
25 PE Plastic ampoules.