Accidental intravascular injections of local anaesthetics may cause immediate (within seconds to a few minutes) systemic toxic reactions. In the event of overdose, systemic toxicity appears later (15-60 minutes after injection) due to the slower increase in local anaesthetic blood concentration.
Hypersensitivity to methyl and/or propyl parahydroxybenzoate (methyl-/propyl paraben), or to their metabolite para amino benzoic acid (PABA). Formulations of lidocaine containing parabens should be avoided in patients allergic to ester local anaesthetics or their metabolite PABA.
The use of a vasoconstrictor is contraindicated for anaesthesia of fingers, toes, tip of nose, ears and penis.
Not applicable
In common with other local anaesthetics, adverse reactions to Xylocaine with Adrenaline are rare and are usually the result of excessively high blood concentrations due to inadvertent intravascular injection, excessive dosage, rapid absorption or occasionally to hypersensitivity, idiosyncrasy or diminished tolerance on the part of the patient. In such circumstances systemic effects occur involving the central nervous system and/or the cardiovascular system.
The adverse reaction profile for Xylocaine with adrenaline is similar to those of other amide local anaesthetics. Adverse reactions caused by the drug per se are difficult to distinguish from the physiological effects of the nerve block (e.g. decrease in blood pressure, bradycardia), events caused directly (e.g. nerve trauma) or indirectly by the needle puncture.
Tabulated list of adverse reactions
Frequencies are defined as very common (>1/10), common (>1/100 to <1/10), uncommon (>1/1,000 to <1/100), rare (>1/10,000 to<1/1,000), very rare (<1/10,000) or not known (cannot be estimated from the available data).
The following table gives a list of the frequencies of undesirable effects:
| System Organ Class | Frequency Classification | Adverse Drug Reaction |
| Immune system disorders | Rare | Allergic reactions, anaphylactic reaction |
| Nervous system disorders | Common | Paraesthesia, dizziness |
| Uncommon | Signs and symptoms of CNS toxicity (convulsions, numbness of tongue and paraesthesia circumoral, tinnitus, tremor, dysarthria, hyperacusis, visual disturbances, CNS depression) | |
| Rare | Neuropathy, peripheral nerve injury, arachnoiditis | |
| Eye disorders | Rare | Diplopia |
| Cardiac disorders | Common | Bradycardia |
| Rare | Cardiac arrest, cardiac arrhythmias | |
| Vascular disorders | Common | Hypotension, hypertension |
| Respiratory, thoracic and mediastinal disorders | Rare | Respiratory depression |
| Gastrointestinal disorders | Common | Nausea, vomiting |
4.8.1 Acute systemic toxicity
Systemic toxic reactions primarily involve the central nervous system (CNS) and the cardiovascular system (CVS). Such reactions are caused by high blood concentrations of a local anaesthetic, which may appear due to (accidental) intravascular injection, overdose or exceptionally rapid absorption from highly vascularised areas. CNS reactions are similar for all amide local anaesthetics, while cardiac reactions are more dependent on the drug, both quantitatively and qualitatively. Signs of toxicity in the central nervous system generally precede cardiovascular toxic effects, unless the patient is receiving a general anaesthetic or is heavily sedated with drugs such as benzodiazepine or barbiturate.
Central nervous system toxicity is a graded response with symptoms and signs of escalating severity. The first symptoms are usually, circumoral paraesthesia, numbness of the tongue, light-headedness, hyperacusis, tinnitus and visual disturbances. Dysarthria, muscular twitching or tremors are more serious and precede the onset of generalised convulsions. These signs must not be mistaken for a neurotic behaviour. Unconsciousness and grand mal convulsions may follow which may last from a few seconds to several minutes. Hypoxia and hypercarbia occur rapidly following convulsions due to the increased muscular activity, together with the interference with respiration and possible loss of functional airways. In severe cases apnoea may occur. Acidosis hyperkalaemia, hypocalcaemia and hypoxia increase and extend the toxic effects of local anaesthetics.
Recovery is due to redistribution of the local anaesthetic drug from the central nervous system and subsequent metabolism and excretion. Recovery may be rapid unless large amounts of the drug have been injected.
Cardiovascular system toxicity may be seen in severe cases and is generally preceded by signs of toxicity in the central nervous system. In patients under heavy sedation or receiving a general anaesthetic, prodromal CNS symptoms may be absent. Hypotension, bradycardia, arrhythmia and even cardiac arrest may occur as a result of high systemic concentrations of local anaesthetics, but in rare cases cardiac arrest has occurred without prodromal CNS effects.
In children, early signs of local anaesthetic toxicity may be difficult to detect in cases where the block is given during general anaesthesia.
4.8.2 Treatment of acute toxicity
If signs of acute systemic toxicity appear, injection of the local anaesthetic should be stopped immediately and CNS symptoms (convulsion, CNS depression) must promptly be treated with appropriate airway/respiratory support and the administration of anticonvulsant drugs.
If circulatory arrest should occur, immediate cardiopulmonary resuscitation should be instituted. Optimal oxygenation and ventilation and circulatory support as well as treatment of acidosis are of vital importance.
If cardiovascular depression occurs (hypotension, bradycardia), appropriate treatment with intravenous fluids, vasopressor, chronotropic and or inotropic agents should be considered. Children should be given doses commensurate with age and weight.
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 website: www.mhra.gov.uk/yellowcard.
Lidocaine and adrenaline are well-established active ingredients.
In animal studies, the signs and symptoms of toxicity noted after high doses of lidocaine are the results of the effects on the central nervous and cardiovascular systems. No drug related adverse effects were seen in the reproduction toxicity studies, neither did lidocaine show any mutagenic potential in either in vitro or in vivo mutagenicity tests. Cancer studies have not been performed with lidocaine, due to the area and duration of therapeutic use for this drug.
Genotoxicity tests with lidocaine showed no evidence of mutagenic potential. A metabolite of lidocaine, 2,6-dimethylaniline, showed weak evidence of activity in some genotoxicity tests. The metabolite 2,6-dimethylaniline has been shown to have carcinogenicity potential in preclinical toxicological studies evaluating chronic exposure. Risk assessments comparing the calculated maximum human exposure from intermittent use of lidocaine, with the exposure used in preclinical studies, indicate a wide margin of safety for clinical use.
Xylocaine 1% with Adrenaline is indicated for regional anaesthesia in adults and children above 1 year of age.
Pharmacotherapeutic group (ATC code): N01B B52
Lidocaine is a local anaesthetic of the amide type. At high doses lidocaine has a quinidine like action on the myocardium i.e. cardiac depressant. All local anaesthetics stimulate the CNS and may produce anxiety, restlessness and tremors.
Lidocaine is readily absorbed from the gastro-intestinal tract, from mucous membranes and through damaged skin. It is rapidly absorbed from injection sites including muscle.
Elimination half-life is 2 hours.
Lidocaine undergoes first pass metabolism in the liver.
Less than 10% of a dose is excreted unchanged via the kidneys.
The speed of onset and duration of action of lidocaine are increased by the addition of a vasoconstrictor and absorption into the site of injection is reduced.
Regional anaesthetic procedures should always be performed in a properly equipped and staffed area. Equipment and drugs necessary for monitoring and emergency resuscitation should be immediately available. When performing major blocks, or using large doses, an IV cannula should be inserted before the local anaesthetic is injected. Clinicians should have received adequate and appropriate training in the procedure to be performed and should be familiar with the diagnosis and treatment of side effects, systemic toxicity or other complications.
Xylocaine with Adrenaline should not be given intravenously.
The effect of local anaesthetics may be reduced if an injection is made into an inflamed or infected area.
Attempts should be made to optimise the patient's condition before major blocks.
Although regional anaesthesia is frequently the optimal anaesthetic technique, some patients require special attention in order to reduce the risk of dangerous side effects:
- Patients with epilepsy.
- Patients with impaired respiratory function.
- Older people and patients in poor general condition.
- Patients with partial or complete heart conduction block - due to the fact that local anaesthetics may depress myocardial conduction.
- Patients with advanced liver disease or severe renal dysfunction.
- Patients treated with anti-arrhythmic drugs class III (e.g. amiodarone) should be under close surveillance and ECG monitoring considered, since cardiac effects may be additive.
- Patients with acute porphyria. Xylocaine solution for injection is probably porphyrinogenic and should only be prescribed to patients with acute porphyria on strong or urgent indications. Appropriate precautions should be taken for all porphyric patients.
Certain local anaesthetic procedures may be associated with serious adverse reactions, regardless of the local anaesthetic drug used, e.g.:
- Injections in the head and neck regions may be made inadvertently into an artery, causing cerebral symptoms even at low doses.
- Paracervical block can sometimes cause foetal bradycardia/tachycardia, and careful monitoring of the foetal heart rate is necessary.
- There have been post-marketing reports of chondrolysis in patients receiving post-operative intra-articular continuous infusion of local anaesthetics. The majority of reported cases of chondrolysis have involved the shoulder joint. Due to multiple contributing factors and inconsistency in the scientific literature regarding mechanism of action, causality has not been established. Intra-articular continuous infusion is not an approved indication for Xylocaine.
Solutions containing adrenaline should be used with caution in patients with hypertension, cardiac disease, cerebrovascular insufficiency hyperthyroidism, advanced diabetes and any other pathological condition that may be aggravated by the effects of adrenaline.
Xylocaine with adrenaline contains sodium metabisulphite, which may cause allergic reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in certain susceptible people. The overall prevalence of sulphite sensitivity in the general population is unknown and probably low. Sulphite sensitivity is seen more frequently in asthmatic than non-asthmatic people.
For local anaesthesia only.
Preservative containing solutions should not be used intracisternally, epidurally, intrathecally or by any route giving access to the cerebrospinal fluid, or intra- or retro-bulbary. The volume to be injected in a single dose should not exceed 15 ml, unless otherwise justified.
Besides the direct anaesthetic affect, local anaesthetics may have a very mild effect on mental function and co-ordination, even in the absence of overt CNS toxicity, and may temporarily impair locomotion and alertness.
Adults and children above 12 years of age
The dosage is 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 single dose of Xylocaine when given with adrenaline is 500 mg.
The following table is a guide for the more commonly used techniques in the average adult. The figures reflect the expected average dose range needed. Standard textbooks should be consulted for factors affecting specific block techniques and for individual patient requirements.
The clinician's experience and knowledge of the patient's physical status are of importance in calculating the required dose. Elderly or debilitated patients require smaller doses, commensurate with age and physical status.
| Type of block | % Conc. | Each dose | Indication | |
| ml | mg | |||
| Field Block (e.g. minor nerve blocks and infiltration) | ||||
| Infiltration | 1 | up to 15 | up to 150 | Surgical operations |
| Intercostals (per nerve) | 1 | 2-5 Max. 15 ml | 20-50 Max. 150 mg | Surgical operations Postoperative pain and fractured ribs |
| Pudendal | 1 | 10 | 100 | Instrumental delivery |
| Major Nerve Block |
|
|
| |
| Paracervical (each side) | 1 | 10 | 100 | Surgical operations and dilatation of cervix Obstetric pain relief |
| Sciatic | 2 | 15 | 300 | Surgical operations |
Paediatric patients 1 to 12 years of age (Xylocaine 1 % with Adrenaline)
Weight-based doses in ml/kg, up to 0.7 ml (7 mg/kg) should be regarded as guidelines for use in paediatric patients. Consider both age and weight for calculation of dosages. In children with a high body weight a gradual reduction of the dosage is often necessary and should be based on the ideal body weight. Standard textbooks should be consulted for factors affecting specific block techniques and for individual patient requirements.
For local anaesthesia only.
Preservative containing solutions should not be used intracisternally, epidurally, intrathecally or by any route giving access to the cerebrospinal fluid, or intra- or retro-bulbary. The volume to be injected in a single dose should not exceed 15 ml, unless otherwise justified.
In general, surgical anaesthesia requires the use of higher concentrations and doses. When a less intense block is required, the use of a lower concentration is indicated. The volume of drug used will affect the extent and spread of anaesthesia.
Care should be taken to prevent acute toxic reactions by avoiding intravascular injection. Careful aspiration before and during the injection is recommended. An accidental intravascular injection may be recognised by a temporary increase in heart rate. The main dose, should be injected slowly, at a rate of 100-200 mg/min, or in incremental doses, while keeping in constant verbal contact with the patient. If toxic symptoms occur, the injection should be stopped immediately.
No special requirements. Any unused medicinal product or waste material should be disposed of in accordance with local requirements.
