Lidocaine Hydrochloride Injection 2%W/V
SUMMARY OF PRODUCT CHARACTERISTICS 1 NAME OF THE MEDICINAL PRODUCT
Lidocaine Hydrochloride Injection 2% w/v
2. QUALITATIVE AND QUANTITATIVE COMPOSITION
Lidocaine Hydrochloride 2% w/v
3. PHARMACEUTICAL FORM
Sterile solution for Injections
4. CLINICAL PARTICULARS
4.1 Therapeutic indications
For use, particularly in emergency, in the prevention of ventricular tachyarrhythmias in patients with suspected or proven acute myocardial infarction. Treatment of ventricular tachyarrhythmias associated with acute myocardial infarction, ventricular extra systoles and ventricular tachycardia.
4.2 Posology and method of administration
Adults and Children over 12 years
1mg/kg body weight. Normal dose 50-100mg (2.5 - 5ml) as a bolus over a few minutes. When necessary the injection can be repeated once or twice at 5 - 10 minute intervals. The effect can be observed within 2 minutes and usually persists for 15 - 20 minutes. Not more than 200-300mg should be administered during 1 hour.
Children under 12 years
The safety and efficacy of lidocaine in children has not been established.
Elderly
In patients with cardiac failure, total plasma clearance will be reduced and lower doses may be required.
4.3 Contraindications
Those with a known hypersensitivity to lidocaine (extremely rare).
Those with known hypersensitivity to other local anaesthetics of the amide type, such as prilocaine, mepivacaine or bupivacaine.
Atrioventricular block is an absolute or relative contra-indication, according to severity and in the absence of a pacemaker. Second or third degree AV-block, hypovolaemia, severe myocardial depression, other serious conduction disturbances and cardiac decompensation, not dependent on treatable tachyarrhythmias, are also contra-indicated.
Lidocaine is also contraindicated in patients with porphyria.
4.4 Special warnings and precautions for use
ECG monitoring should be instituted when lidocaine is administered as an intravenous infusion.
Caution should be observed in patients with cardiac decompensation and hypotension or posterior diaphragmal infarction with a tendency towards heart block.
Lidocaine should be administered with caution to patients with bradycardia, untreated first-degree AV-block with bifascicular block, congestive heart failure, impaired cardiac conduction or hypokalaemia.
Use with caution in patients with epilepsy or respiratory impairment.
Severely impaired liver or kidney function may mean a risk of accumulation and toxic reactions as lidocaine is mainly metabolised in the liver and the metabolites are excreted by the kidneys. Caution should be observed during repeated treatment with lidocaine in patients with these functional disorders.
When high doses are used and the patients myocardial function is impaired, combination with other drugs which reduce the excitability of cardiac muscle requires caution.
Lidocaine treatment may aggravate arrhythmias.
The potassium concentration should be normalised before lidocaine treatment is started.
In patients with bradycardia complicated by ventricular tachyarrhythmia, lidocaine may have to be combined with atropine or atropine-like drugs or pacemaker treatment.
4.5 Interactions with other medicinal products and other forms of interaction
Propranolol and cimetidine can impair the metabolism of lidocaine. Elimination will be delayed, the duration of action prolonged and the risk of adverse reactions increased.
Lidocaine prolongs the action of suxamethonium. There is an increased risk of ventricular arrhythmias with concomitant use of antibacterials such as quinupristin and dalfopristin.
Using other anti-arrhythmic agents can result in increased myocardial depression.
Use of diuretics such as acetazolamide, loop diuretics and thiazides may antagonise the effect of lidocaine by hypokalaemia. Caution is advised when taking antidepressants such as reboxetine and in patients with epilepsy, as long term use of drugs such as phenytoin or barbiturates may increase dosage requirements for lidocaine.
4.6 Pregnancy and lactation
Lidocaine has been used by a large number of pregnant women and women of child-bearing age. No specific disturbances to the reproductive process have so far been reported, e.g. an increased incidence of malformation or direct or indirect harmful effect on the foetus.
It is not known whether lidocaine is excreted in breast milk.
4.7 Effects on ability to drive and use machines
None known.
4.8
Undesirable effects
Most frequent adverse reactions from the central and peripheral nervous system. They occur in 5-10% of the patients and are mostly dose related.
Central and peripheral nervous system: Dizziness, light-headedness, paraesthesia, nystagmus, fine twitching and drowsiness. Rarely persistent dizziness, tinnitus, confusion, blurred vision, tremor, convulsions, loss of consciousness and respiratory depression.
Hypersensitivity has been reported, although less frequently than with the ester-type local anaesthetics.
Cardiovascular: Rarely hypotension and bradycardia, which may lead to cardiac arrest.
4.9 Overdose
Poisoning due to an overdose of lidocaine may lead to CNS excitation with paraesthesia, muscle twitching and convulsions, atrioventricular block, sinoatrial block or arrest, asystole, myocardial depression, severe hypotension and cardiac arrest.
Treatment should include close monitoring of cardiovascular and respiratory function and electrolytes. If convulsions occur, maintenance of a patent airway is mandatory and assisted or controlled ventilation with oxygen may be required. Convulsions may be controlled with intravenous diazepam or a short-acting barbiturate.
Cardiovascular complications should be treated symptomatically, which may require the use of sympathomimetic agents (e.g. noradrenaline, metaraminol), or inotropic agents (e.g. dopamine, dobutamine). Temporary pacing may be required for AV block.
Lidocaine is usually eliminated rapidly from the body, but elimination may be delayed in severe hypotension, cardiac failure or cardiogenic shock.
5. PHARMACOLOGICAL PROPERTIES
5.1 Pharmacodynamic properties
Treatment with lidocaine is easily managed, owing to rapid distribution, metabolism and excretion. During the first half-hour after an intravenous injection, the plasma concentration falls with a half-life of 10-15 minutes (a-phase), owing to the rapid distribution to different body tissues, including the heart. The therapeutic plasma concentration range is 1.5-6p,g/ml (6.5 -2.6pmol/L). The plasma protein binding is about 70%. The apparent distribution volume is approximately 1 L/kg.
5.2 Pharmacokinetic properties
Lidocaine is mainly metabolised by the liver (70-90%). The metabolites have a weaker antiarrhythmic action and are excreted by the kidneys. The half-time in the elimination (P) phase is 90-120 minutes. Less than 10% of the dose of lidocaine is excreted unchanged in the urine. There is a risk of accumulation of metabolites if the renal function is impaired. Heart failure and liver disease also mean a risk of accumulation of lidocaine.
During continuous infusion, steady state conditions are not reached until after 6-8 hours. In order to reach an adequate plasma concentration rapidly and maintain a therapeutic concentration, one or more intravenous injections must be given initially.
5.3 Preclinical safety data
None stated
6. PHARMACEUTICAL PARTICULARS
6.1 List of excipients
Sodium Chloride Dilute Hydrochloric Acid Sodium Hydroxide Solution Water for Injections
6.2 Incompatibilities
Lidocaine hydrochloride has been reported to be incompatible in solution with amphotericin, sulphadiazine sodium, methohexitone sodium, cephazolin sodium, or phenytoin sodium.
The Lidocaine content of buffered cardioplegic solutions has been reported to decrease when stored in polyvinyl chloride containers at ambient temperatures but not when stored at 4oC. This loss appeared to result from pH-dependent
adsorption of Lidocaine onto the plastic and did not occur when Lidocaine solutions were stored in glass bottles.
6.3 Shelf life
36 months.
6.4 Special precautions for storage
Do not store above 25oC. Keep the syringe in the outer box.
6.5 Nature and contents of container
5 &10ml Type 1 prefilled syringe with rubber stopper and rubber tip cap.
6.6 Instructions for use/handling
Use once and discard any remaining solution at the end of the session. No needle is provided with the syringe
7 MARKETING AUTHORISATION HOLDER
Aurum Pharmaceuticals Ltd Bampton Road Romford RM3 8UG
8. MARKETING AUTHORISATION NUMBER
PL 12064/0049
9. DATE OF FIRST AUTHORISATION/RENEWAL OF THE AUTHORISATION
May 1999
10.
DATE OF REVISION OF TEXT
February 2004