1. Name Of The Medicinal Product
Lidocaine Hydrochloride Injection BP 2% w/v.
2. Qualitative And Quantitative Composition
Each 1ml of solution contains 20mg of Lidocaine Hydrochloride.
3. Pharmaceutical Form
Solution for injection.
4. Clinical Particulars
4.1 Therapeutic Indications
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.
4.2 Posology And Method Of Administration
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 maximum dose for healthy adults should not exceed 200 mg [or 500mg if given in solutions containing adrenaline (epinephrine)].
Children and elderly or debilitated patients require smaller doses, commensurate with age & physical status.
4.3 Contraindications
Known hypersensitivity to anaesthetics of the amide type; hypovolemia; complete heart block.
Solutions containing adrenaline (epinephrine) should not be used in areas of the body supplied by end arteries or otherwise having a compromised blood supply such as digits, nose, ear or penis. Solutions containing adrenaline (epinephrine) should not be given intravenously.
4.4 Special Warnings And Precautions For Use
As with other local anaesthetics, lidocaine should be used with caution in patients with epilepsy, cardiac conduction disturbances, congestive cardiac failure, bradycardia or impaired respiratory function, if the dose or site of administration is likely to produce high blood levels. Lidocaine is metabolised in the liver and it should be used with caution in patients with impaired hepatic function.
Facilities for resuscitation should be available when administering local anaesthetics.
The effect of local anaesthetics may be reduced if the injection is made into an inflamed or infected area.
Solutions containing adrenaline (epinephrine) should be used with caution in patients with hypertension, cardiac disease, cerebrovascular insufficiency, thyrotoxicosis, in patients taking tricyclic antidepressants, MAOI's or receiving potent anaesthetic agents.
Lidocaine is considered to be unsafe in patients with porphyria because it has shown to be porphyrogenic in animals.
4.5 Interaction With Other Medicinal Products And Other Forms Of Interaction
The speed of onset and duration of action of lidocaine are increased by the addition of a vasoconstrictor such as adrenaline (epinephrine) and absorption from the site of injection is reduced.
Dopamine and 5-hydroxytryptamine depletion both reduce the convulsant threshold of lidocaine, and the concomitant use of pethidine increases the incidence of lidocaine-induced convulsions in animals.
Cimetidine and propranolol depress microsomal enzyme activity, thus enhancing lidocaine toxicity during anti-arrhythmic infusions if concomitantly administered with these drugs.
The use of prenylamine in the prophylaxis of angina contra-indicates the use of lidocaine for arrhythmia since this combination may precipitate A-V block and ventricular tachycardia.
The cardiac depressant effects of lidocaine are additive with those of beta-blockers, and of other antiarrhythmics.
Hypokalemia produced by acetazolamide, loop diuretics, and thiazides antagonizes the effect of lidocaine.
There is increased risk of ventricular arrhythmias when lidocaine is given with quinupristin/dalfopristin - avoid concomitant use.
Neuromuscular blockade may be enhanced and prolonged when lidocaine is given with suxamethonium.
4.6 Pregnancy And Lactation
Although animal studies have revealed no evidence of harm to the foetus, lidocaine should not be administered during early pregnancy unless the benefits are considered to outweigh the risks.
Small amounts of lidocaine are secreted into breast milk and the possibility of an allergic reaction in the infant, albeit remote, should be borne in mind when using lidocaine in nursing mothers.
4.7 Effects On Ability To Drive And Use Machines
Where outpatient 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.
4.8 Undesirable Effects
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.
CNS reactions may be excitatory and/or depressant and may manifest as nervousness, tremor, blurred vision, nausea and vomiting, followed by drowsiness, coma and possibly respiratory arrest. The excitatory reactions may be brief or may not occur at all, so that the first signs of toxicity may be drowsiness, followed by coma and respiratory failure. Cardiovascular reactions are depressant and may manifest as hypotension, bradycardia, myocardial depression and possibly cardiac arrest.
Allergic reactions are rare. They may be characterised by cutaneous lesions, urticaria, oedema or anaphylactoid reactions. Skin testing for allergy to lidocaine is not considered to be reliable.
4.9 Overdose
The effects of overdosage involve the CNS, where reactions may be excitatory and/or depressant, and the CVS where the effects are depressant. In the event of an overdose, immediate steps should be taken to maintain the circulation and respiration and to control convulsions.
A patent airway should be established and oxygen should be administered, together with assisted ventilation if necessary. The circulation should be maintained with infusions of plasma or intravenous fluids. Where further supportive treatment of circulatory depression is required, use of a vasopressor agent may be considered although this involves a risk of CNS excitation. Convulsions may be controlled by the intravenous administration of diazepam or thiopental sodium, bearing in mind that anti-convulsant drugs may also depress respiration and the circulation. If cardiac arrest should occur, standard cardiopulmonary resuscitation procedures should be instituted.
Dialysis is of negligible value in the treatment of acute overdosage with lidocaine.
5. Pharmacological Properties
5.1 Pharmacodynamic Properties
Lidocaine is a local anaesthetic of the amide type. It is used to provide local anaesthesia at various sites in the body and it acts by inhibiting the ionic refluxes required for the initiation and conduction of impulses, thereby stabilising the neuronal membrane. In addition to blocking conduction in nerve axons in the peripheral nervous system, lidocaine has important effects on the central nervous system and cardiovascular system. After absorption, lidocaine may cause stimulation of the CNS followed by depression and in the cardiovascular system, it acts primarily on the myocardium where it may produce decreases in electrical excitability, conduction rate and force of contraction.
5.2 Pharmacokinetic Properties
Lidocaine is absorbed from injection sites including muscle and its rate of absorption is determined by factors such as the site of administration and the tissue vascularity. Except for intravascular administration, the highest blood levels occur following intercostal nerve block and the lowest after subcutaneous administration. Lidocaine is bound to plasma proteins, including alpha-1-acid-glycoprotein. The drug crosses the blood-brain and placental barriers.
Lidocaine is metabolised in the liver and about 90% of a given dose undergoes N-dealkylation to form monoethylglycinexylidide and glycinexylidide, both of which may contribute to the therapeutic and toxic effects of lidocaine. 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.
5.3 Preclinical Safety Data
No further relevant information other than that which is included in other sections of the Summary of Product Characteristics.
6. Pharmaceutical Particulars
6.1 List Of Excipients
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6.2 Incompatibilities
Lidocaine caused precipitation of amphotericin, methohexital sodium and sulfadiazine sodium in glucose injection. It is recommended that admixtures of lidocaine and glyceryltrinitrate should be avoided.
6.3 Shelf Life
3 years (36 months).
6.4 Special Precautions For Storage
Do not store above 25ºC.
6.5 Nature And Contents Of Container
2ml, 5ml, 10ml & 20ml translucent plastic ampoules, polypropylene Ph. Eur., packed in cardboard cartons to contain 10, 20, 50 and 100 ampoules.
6.6 Special Precautions For Disposal And Other Handling
If only part used, discard the remaining solution.
Administrative Data
7. Marketing Authorisation Holder
Antigen International Ltd
Roscrea
Co. Tipperary
Ireland
8. Marketing Authorisation Number(S)
PL 02848/0177
9. Date Of First Authorisation/Renewal Of The Authorisation
22/03/2006
10. Date Of Revision Of The Text
22/03/2006
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