LIDOCAINE INJECTION BP MINIJET 2%W/V - summary of medicine characteristics

1 NAME OF THE MEDICINAL PRODUCT

Lidocaine Injection BP Minijet 2% w/v.

2. QUALITATIVE AND QUANTITATIVE COMPOSITION

Lidocaine Hydrochloride BP 20 mg in 1 ml.

3. PHARMACEUTICAL FORM

Sterile aqueous solution for infiltration injection or intravenous administration.

4. CLINICAL PARTICULARS

4.1 Therapeutic indications

For local anaesthesia by infiltration, intravenous regional anaesthesia and nerve blocks.

By intravenous injection for emergency management or ventricular arrhythmias, particularly after myocardial infarction and cardiac surgery.

4.2 Posology and method of administration

For local anaesthesia:

The dosage varies depending upon the area to be anaesthetised, vascularity of the tissues, number of neuronal segments to be blocked, individual tolerance and the anaesthetic technique. The lowest dosage needed to provide anaesthesia should be administered.

Adults: the usual dose should not exceed 200mg.

Children: the usual dose should not exceed 3mg/kg.

For epidurals, a test dose should be administered at least 5 minutes before total dose to prevent inadvertent intravascular or subarachnoid injection.

For continuous epidural, caudal or paracervical anaesthesia, the maximal dose should not be

repeated at intervals under 90 minutes.

For i.v regional anaesthesia (Bier's block), the tourniquet should not be released until at least 20 minutes after administration.

For intravenous use in cardiac arrhythmias:

Adults: The usual dose is 50 to l00mg administered intravenously under ECG monitoring. This dose may be injected at a rate of approximately 25 to 50mg (2.5 to 5.0ml 1% solution or 1.25 to 2.5ml 2% solution) per minute. A sufficient period of time should be allowed to enable a slow circulation to carry the drug to the site of action. If the initial dose of 50 to l00mg does not produce the desired response, a second dose may be given after 5 minutes. No more than 200 to 300mg of lidocaine should be administered during a one hour period.

Following a single injection in those patients in whom arrhythmia tends to recur and who are incapable of receiving oral antiarrhythmic therapy, intravenous infusions of lidocaine may be administered at the rate of 1 to 4mg/minute (20 to 50mcg/kg/minute). I.V. infusions must be given under ECG monitoring to avoid potential overdosage and toxicity. The infusion should be terminated as soon as the patient's basic cardiac rhythm appears to be stable or at the earliest signs of toxicity. It should rarely be necessary to continue the infusion beyond 24 hours. As soon as possible, patients should be changed to an oral antiarrhythmic agent for maintenance therapy.

Children: Experience with lidocaine is limited. A suggested paediatric dose is a loading dose of 0.8 to 1mg/kg repeated if necessary up to 3–5mg/kg, followed by continuous infusion of 10 to 50mcg/kg/minute.

Elderly: Doses may need to be reduced depending on age and physical state.

4.3 Contra-indications

Lidocaine is contraindicated in patients with known hypersensitivity to local anaesthetics of the amide type or to any other component of the product and in patients with porphyria.

4.4 Special warnings and precautions for use

Constant ECG monitoring is necessary during IV administration. Resuscitative equipment and drugs should be immediately available for the management of severe adverse cardiovascular, respiratory or central nervous system effects. If severe reactions occur, lidocaine should be discontinued.

Use with caution in patients with epilepsy, liver disease, congestive heart failure, severe renal disease, marked hypoxia, severe respiratory depression, hypovolaemia or shock and in patients with any form of heart block, atrioventricular conduction disturbance (in line with Sections 4.5 and 4.8) or sinus bradycardia. Hypokalaemia, hyperkalaemia, hypoxia and disorders of acid-base balance should be corrected before treatment with lidocaine begins.

Blood pressure should be monitored during spinal anaethesia.

Intra-articular administration of lidocaine may cause chondrotoxicity.

4.5 Interaction with other medicinal products and other forms of interaction

Propranolol and cimetidine may reduce the renal and hepatic clearance of lidocaine, thus increasing toxicity.

The cardiac depressant effects of lidocaine are additive to those of other antiarrhythmic agents particularly class I (e.g. kinidine, disopyramide) or class III (e.g.amiodarone or sotalol). Caution should be exercised particularly in patients with cardiac decompensation.

Inhibition of CYP1A2 by fluvoxamine considerably reduces elimination of lidocaine and increases the risk of lidocaine toxicity. Concomitant use of both fluvoxamine and a CYP3A4 inhibitor such as erythromycin can further increase lidocaine concentrations. Because lidocaine possesses a narrow therapeutic window, doses of lidocaine may need to be adjusted accordingly. Conversely, reduced serum lidocaine concentrations may result from drugs that may stimulate the hepatic metabolism of lidocaine (e.g. phenytoin, oral HRT).

Hypokalaemia produced by acetazolamide, loop diuretics and thiazides antagonizes the effect of lidocaine.

Propranolol, metoprolol and nadolol may increase lidocaine levels by 20% to 30%.

Lidocaine is markedly bound to □ l-acid glycoprotein (AAG). AAG concentrations may be reduced by oestrogens leading to a higher free fraction of lidocaine in women than in men and the free fraction is further increased during pregnancy and in women taking oral contraceptives or HRT.

Lidocaine prolongs the action of neuromuscular blocking agents such as suxamethonium and cisatracurium.

Epidural administration of lidocaine in combination with clonidine, adrenaline or clonidine plus adrenaline significantly reduces the Cmax of lidocaine.

4.6 Use during pregnancy and lactation

The safe use of lidocaine has not been established with respect to possible adverse effects upon foetal development. Lidocaine crosses the placenta and blood brain barrier. Lidocaine is excreted in breast milk and so should be used with caution in nursing women.

4.7 Effects on ability to drive and use machines

Not applicable; this preparation is intended for use only in emergencies.

4.8 Undesirable effects

Adverse effects are usually due to inadvertent intravenous administration or overdosage.

Allergic reactions (including anaphylaxis) have been reported rarely.

The following systemic reactions have been reported in association with lidocaine:

Central nervous system: light-headedness, drowsiness, dizziness, apprehension, nervousness, euphoria, tinnitus, blurred or double vision, nystagmus, headache, nausea, vomiting, sensations of heat, cold or numbness, twitching, tremors, paraesthesia, convulsions, unconsciousness, respiratory depression and arrest, transient neurological symptoms i.e. pain and/or dysaesthesia in the buttocks or legs.

Cardiovascular system: hypotension, arrhythmia, cardiovascular collapse and bradycardia which may lead to cardiac arrest. AV block and myocardial depression.

Psychiatric disorders: confusion and psychosis.

Blood and the lymphatic system disorders: methaemoglobi­naemia.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard.

4.9 Overdose

Symptoms: reactions due to overdose with Lidocaine (high plasma levels) are systemic and involve the central nervous and cardiovascular systems. Effects include medullary depression, tonic and clonic convulsions and cardiovascular collapse.

Treatment: institute emergency resuscitative procedures and administer the drugs necessary to manage the severe reaction. For severe convulsions, small increments of diazepam or an ultra-short acting barbiturate (thiopentone), or if not available, a short acting barbiturate (pentobarbitone or quinalbarbitone), or if the patient is under anaesthesia, a short-acting muscle relaxant (suxamethonium) may be given intravenously. Patency of the airway and adequacy of ventilation must be assured.

Should circulatory depression occur vasopressors such as metaraminol may be used.

5 PHARMACOLOGICAL PROPERTIES

5.1 Pharmacodynamic properties

ATC code: C01BB 01 Antiarrhythmics, Class 1B and N01BB 02 local anaesthetic.

Lidocaine stabilises the neuronal membrane and prevents the initiation and transmission of nerve impulses, thereby effecting local anaesthetic action. The onset of action is rapid and the blockade may last up to 2 hours.

In the heart, lidocaine reduces automaticity by decreasing the rate of diastolic (phase 4) depolarisation. Lidocaine is considered as a class 1b (membrane stabilising) antiarrhythmic agent. The duration of the action potential is decreased due to blockade of the sodium channel and the refractory period is shortened.

5.2. Pharmacokinetic properties

Lidocaine is rapidly distributed to all body tissues. About 65% is plasma bound. Lidocaine crosses the placenta and the blood brain barrier. The plasma half life is 1.6 hours. About 80% of the dose is metabolised in the liver. Less than 10% is found unchanged in the urine.

5.3. Preclinical safety data

Not applicable since lidocaine has been used in clinical practice for many years and its effects in man are well known.

6. PHARMACEUTICAL PARTICULARS

6.1. List of excipients

Hydrochloric Acid

Sodium Chloride

Sodium Hydroxide

Water for Injection

6.2. Incompatibilities

None known.

6.3. Shelf life

3 years.

6.4. Special precautions for storage

Store below 25°C.

6.5. Nature and contents of container

The solution is contained in a USP type I glass vial with an elastomeric closure which meets all the relevant USP specifications. The product is available as a 2% solution in a 5ml vial.

6.6. Instructions for use/handling

The container is specially designed for use with the IMS Minijet injector.

7 MARKETING AUTHORISATION HOLDER

International Medication Systems (UK) Limited

First Floor, Templeback

10 Temple Back

Bristol

United Kingdom

BS1 6FL

8. MARKETING AUTHORISATION NUMBER

PL 03265/0006R