- lidocaine hydrochloride
POM: Prescription only medicine
This information is intended for use by health professionals
In ventricular arrhythmiasThe usual adult IV bolus dose is 50-100 mg administered at a rate of approximately 25-50 mg per minute. If the desired response is not achieved, a second dose may be administered 5 minutes after completion of the first injection. Not more than 200-300 mg should be administered during a one hour period. Elderly patients and those with congestive heart failure or cardiogenic shock may require smaller bolus doses.Maintenance infusion of a 0.2 or 0.4% solution in 5% glucose.Adults: 20-50 micrograms/kg/minute (1-4 mg/minute in an average 70 kg adult).Slower infusion rates should be used in patients with congestive heart failure or liver disease; no dosing modification appears necessary in patients with renal failure. When arrhythmias reappear during a constant infusion of Lidocaine, a small bolus may be given to rapidly increase plasma concentration of the drug; the infusion rate is increased simultaneously. The infusion should be terminated as soon as the patient's basic cardiac rhythm appears to be stable or at the earliest sign of toxicity.Infants and children may be given an initial IV bolus of 0.5-1 mg/kg. This dose may be repeated according to the response of the patient, but the total dose should not exceed 3-5 mg/kg. A maintenance IV infusion of 10-50 micrograms/kg per minute may be given via an infusion pump.For advanced cardiac life support in children, the recommended dosage is an initial IV bolus of 1 mg/kg. If ventricular tachycardia or ventricular fibrillation is not corrected following defibrillation and an initial bolus, an IV infusion should be started at a rate of 20-50 mcg/kg per minute.Constant ECG monitoring is recommended during therapy with Lidocaine Hydrochloride, however if this equipment is not available and a ventricular arrhythmia is suspected, a single IM dose may be administered if bradycardia is not present. The deltoid muscle is the preferred site for IM injection.
In Local AnaesthesiaUsual doses should generally be reduced in children and in elderly or debilitated patients. To minimise the possibility of toxic reactions, children should be given Lidocaine Hydrochloride solutions in concentrations of 0.5% or 1%.Single doses of Lidocaine (for anaesthesia other than spinal) should not exceed 4.5 mg/kg (or 200 mg) in adults or children 12 18 years of age. Lidocaine by local infiltration for children under the age of 12 years should not exceed 3mg/kg, repeated not more often than every 4 hours. For spinal anaesthesia, up to 100 mg of the drug may be given. For continuous epidural or caudal anaesthesia, the maximum dose should not be repeated at intervals of less than 1.5 hours. For paracervical block for obstetric analgesia (including abortion) the maximum recommended dosage (200 mg) should not be repeated at intervals of less than 1.5 hours. For IV regional anaesthesia in adults using a 0.5% solution, the dose administered should not exceed 4 mg/kg. Solutions of 1% Lidocaine Hydrochloride (without preservative) are used for epidural or caudal anaesthesia. To prevent intravascular or subarachnoid injection of a large epidural dose of Lidocaine, a test dose of 2-5 mls should be injected at least 5 minutes prior to administering the total dose.In epidural anaesthesia 2-3 mls of 1% solution is usually required for each dermatome to be anaesthetised.In caudal block for production of obstetric analgesia or in epidural thoracic block, 20-30 mls of a 1% solution (200-300 mg) of the drug may be used. For epidural lumbar anaesthesia, the dose is 25-30 mls (250-300 mg) of a 1% solution.For intercostal nerve block: 3 mls of a 1% solution (30 mg).For paravertebral nerve block: 3-5 mls of a 1% solution (30-50 mg).For pudendal nerve block (each side): 10 mls of a 1% solution (100 mg).For paracervical nerve block (each side) for obstetric analgesia: 10 mls of a 1% solution (100 mg).For sympathetic nerve blocks: Cervical (stellate ganglion) nerve block: 5 mls of a 1% solution (50 mg).Lumbar nerve block: 5-10 mls of a 1% solution (50-100mg).For percutaneous infiltration anaesthesia: 1-60 mls of a 0.5% solution or 0.5 to 30ml of a 1% solution (5-300mg).For IV regional anaesthesia: 10-60 mls of 0.5% solution (50-300 mg).
Effects of Lidocaine on other medicinal productsLidocaine should be used with caution in patients receiving other local anaesthetics or agents structurally related 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 enhanced and prolonged neuromuscular blockade in patients treated concurrently with muscle relaxants (e.g. suxamethonium).
Effects of other medicinal products on LidocaineThe clearance of Lidocaine may be reduced by beta-adrenoceptor blocking agents (e.g. propranolol) and by cimetidine, requiring a reduction in the dosage of lidocaine. Increase in serum levels of lidocaine may also occur with anti-viral agents (e.g. amprenavir, atazanavir, darunavir, lopinavir).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), or 5HT3 antagonists (e.g. tropisetron, dolasetron). While adrenaline (epinephrine) when used in conjunction with lidocaine might decrease vascular absorption, it greatly increases the danger of ventricular tachycardia and fibrillation if accidentally injected intravenously.Cardiovascular collapse has been reported following the use of bupivacaine in patients on treatment with verapamil and timolol; Lidocaine is closely related to bupivacaine. Concomitant use of quinupristin/dalfopristin should be avoided.Hypokalaemia produced by acetazolamide, loop diuretics and thiazides may antagonize the effect of lidocaine if administered concomitantly (see section 4.4).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).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.Lidocaine is markedly bound to α-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.
PregnancyAlthough 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 given by epidural or paracervical block, especially in large doses, or by local perineal infiltration prior to delivery crosses rapidly into the foetal circulation. Elevated lidocaine levels may persist in the newborn for at least 48 hours after delivery. Foetal bradycardia or neonatal bradycardia, hypotonia or respiratory depression may occur.
LactationSmall 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.
Immune system disordersHypersensitivity reactions (allergic or anaphylactoid reactions, anaphylactic shock) see also Skin & subcutaneous tissue disordersSkin testing for allergy to Lidocaine is not considered to be reliable.
Nervous & Psychiatric disordersNeurological signs of systemic toxicity include dizziness or light-headedness, nervousness, tremor, circumoral paraesthesia, tongue numbness, drowsiness, convulsions, coma.Nervous system reactions may be excitatory and or depressant. Signs of CNS stimulation may be brief, or may not occur at all, so that the first signs of toxicity may be confusion and drowsiness, followed by coma and respiratory failure.Neurological complications of spinal anaesthesia include transient neurological symptoms such as pain of the lower back, buttock and legs. These symptoms usually develop within twenty-four hours of anaesthesia and resolve within a few days. Isolated cases of arachnoiditis or cauda equina syndrome, with persistent paraesthesia, bowel and urinary dysfunction, or lower limb paralysis have been reported following spinal anaesthesia with lidocaine and other similar agents. The majority of cases have been associated with hyperbaric concentrations of lidocaine or prolonged spinal infusion.
Eye disordersBlurred 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 (see section 4.4 Special warnings and precautions for use).
Ear and labyrinth disordersTinnitus, hyperacusis
Cardiac and vascular disordersCardiovascular reactions are depressant and may manifest as hypotension, bradycardia, myocardial depression, cardiac arrhythmias and possibly cardiac arrest or circulatory collapse.Hypotension may accompany spinal and epidural anaesthesia. Isolated cases of bradycardia and cardiac arrest have also been reported.
Respiratory, thoracic or mediastinal disordersDyspnoea, bronchospasm, respiratory depression, respiratory arrest
Gastrointestinal disordersNausea, vomiting
Skin & subcutaneous tissue disordersRash, urticaria, oedema (including angioedema, face oedema)
Blood and the lymphatic system disordersMethaemoglobinaemia.
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: .
Symptoms of acute systemic toxicityCentral nervous system toxicity presents with symptoms of increasing severity. Patients may present initially with circumoral paraesthesia, numbness of the tongue, light-headedness, hyperacusis and tinnitus. Visual disturbance and muscular tremors or muscle twitching are more serious and precede the onset of generalised convulsions. These signs must not be mistaken for neurotic behaviour. Unconsciousness and grand mal convulsions may follow, which may last from a few seconds to several minutes. Hypoxia and hypercapnia occur rapidly following convulsions due to increased 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 toxicityIf signs of acute systemic toxicity appear, injection of the anaesthetic should be stopped immediately.Treatment will be required if convulsions and CNS depression occurs. The objectives of treatment are to maintain oxygenation, stop the convulsions and support the circulation. A patent airway should be established and oxygen should be administered, together with assisted ventilation (mask and bag) 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 central nervous system excitation. If the convulsions do not stop spontaneously in 15-20 seconds, they may be controlled by the intravenous administration of Diazepam or Thiopentone Sodium, bearing in mind that anti-convulsant drugs may also depress respiration and the circulation. Prolonged convulsions may jeopardise the patient's ventilation and oxygenation and early endotracheal intubation should be considered. If cardiac arrest should occur, standard cardiopulmonary resuscitation procedures should be instituted. Continual optimal oxygenation and ventilation and circulatory support as well as treatment of acidosis are of vital importance.Dialysis is of negligible value in the treatment of acute overdosage with Lidocaine
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