Lidocaine

General characteristics. Structure:

Active ingredient - lidocaine a hydrochloride monohydrate of 20 mg.

Auxiliary a veshchesta - sodium chloride of 6,0 mg; sodium hydroxide to рН 5,0-7,0; water for injections - to 1 ml.

Pharmacological properties:

Pharmacodynamics. Possesses mestnoanesteziruyushchy action, blocks potentsialzavisimy natrium channels that interferes with generation of impulses in the terminations of sensory nerves and to carrying out impulses on nerve fibrils. Suppresses carrying out not only painful impulses, but also impulses of other modality.

The anesthetic effect of lidocaine is 2-6 times stronger, than Procainum (works quicker and longer - up to 75 min., and after addition of Epinephrinum - more than 2 h). At topical administration expands vessels, has no local irritative effect.

Pharmacokinetics: Absorption - full (speed of absorption depends on an injection site and a dose). TCmax at in oil - 30-45 min. Communication with proteins of plasma - 50-80%. It is distributed quickly (the semi-distribution period - 6-9 min.), at first come to well krovosnabzhayemy fabrics (heart, lungs, a brain, a liver, a spleen), then to fatty and muscular fabrics. Gets through GEB and a placental barrier, cosecretes with maternal milk (40% of concentration in mother's plasma).

Is metabolized in a liver (for 90-95%) with participation of P450 cytochrome by dealkylation of an amino group and a rupture of amide communication with formation of active metabolites (моноэтилглицинсилидин and глицинсилидин) which T1/2 makes 2 h and 10 h respectively. At liver diseases intensity of metabolism decreases and makes from 50% to 10% of a normal amount.

It is removed with bile (a part of a dose is exposed to a reabsorption in a GIT) and kidneys (to 10% in not changed look). At HPN cumulation of metabolites is possible. Acidulation of urine promotes increase in removal of lidocaine.

Indications to use:

All types of local anesthesia (anesthesia at an injury, surgical interventions, including Cesarean section, a labor pain relief, holding painful diagnostic procedures, for example, an arthroscopy):
- terminal (surface) anesthesia,

- local infiltration anesthesia (subconjunctival),

- conduction anesthesia (including in stomatology, intercostal blockade, cervical vagosympathetic, in/in regional anesthesia),

- caudal or lumbar epidural blockade,

- spinal (subarachnoidal) anesthesia, conduction (retrobulbar, parabulbar) anesthesia.

Route of administration and doses:

Infiltration anesthesia - 0.125%, 0.25%, 0.5% solutions are used; for achievement of an infiltration anesthesia about 60 ml (5-300 mg) of 0.5% of solution or to 30 ml of 1% of solution are used.
Solutions apply 1 and 2% to conduction anesthesia (anesthesia of peripheral nerves, including at blockade of neuroplexes); the maximum general dose - to 400 mg (40 ml of 1% of solution and 20 ml of 2% of solution of lidocaine). For blockade of neuroplexes - 10-20 ml of 1% of solution or 5-10 ml of 2% of solution.
Epidural anesthesia - for receiving an analgesia is used by 25-30 ml (250-300 mg) of 1% of solution; for receiving anesthesia of 15-20 ml (225-300 mg) of 1.5% of solution or 10-15 ml (200-300 mg) of 2% of solution; for thoracic epidural anesthesia - 20-30 ml (200-300 mg) of 1% of solution. It is not recommended to use continuous administration of anesthetic by means of a catheter; introduction of the maximum dose should not repeat more often than in 90 min.
When using caudal anesthesia: in obstetric practice of 200-300 mg (10-15 ml) of 2% of solution; in surgical practice - 15-20 ml (225-300 mg) of 1.5% of solution. It is not recommended to use continuous administration of anesthetic by means of a catheter; introduction of the maximum dose should not repeat more often than in 90 min.
For intravenous regional anesthesia - 10-60 ml (50-300 mg) of 0.5% of solution.
For conduction anesthesia of peripheral nerves: humeral - 15-20 ml (225-300 mg) of 1.5% of solution; in dental practice - 1-5 ml (20-100 mg) of 2% of solution; blockade of intercostal nerves - 3 ml (30 mg) of 1% of solution; paracervical anesthesia - 10 ml (100 mg) of 1% of solution in each party, if necessary perhaps repeated introduction not less than in 1.5 h; juxtaspinal anesthesia - from 3 to 5 ml (30-50 mg) of 1% of solution.
Retrobulbar anesthesia - 3-5 ml (120-200 mg) of 4% of solution, 3.0-4.0 ml of 2% of solution.
Parabulbar anesthesia - 1.0-2.0 ml 2%rastvora.
Local infiltration (subconjunctival) - 0.5-1.0 ml of 2% of solution.
Vagosympathetic blockade: cervical department (a star-shaped node) - 5 ml (50 mg) of 1% of solution, lumbar - 5-10 ml (50-100 mg) of 1% of solution.
Transtracheal anesthesia - 2-3 ml (80-120 mg) of 4% of solution, the combination to local intrafaringealny introduction of 4% of solution in the form of spray is possible, the maximum dose in this case should not exceed 5 ml (200 mg) or 3 mg/kg.
The maximum dose for adults - no more than 4.5 mg/kg or 300 mg; for in regional anesthesia - no more than 4 mg/kg.
The recommended doses for children at neuromuscular blockade - to 5 mg/kg of 0.25-1% of solution, at in regional anesthesia - 3 mg/kg of 0.25-0.5% of solution.
The maximum dose for children - 5 mg/kg.
The effect of lidocaine can be extended with addition of 0.1% of solution of Epinephrinum (0.1 ml on 20 ml of lidocaine). In this case at regional anesthesia the dose of lidocaine can be increased to 600 mg.

Features of use:

Extra care should be shown when carrying out local anesthesia of bodies rich with blood vessels; it is necessary to avoid an intravascular injection during introduction.

At introduction to vaskulyarizirovanny fabrics it is recommended to carry out aspiration test.

It is necessary to cancel MAO inhibitors not less than in 10 days prior to planning of carrying out subarachnoidal anesthesia by means of lidocaine.

During treatment it is necessary to be careful at control of vehicles and occupation other potentially dangerous types of activity demanding the increased concentration of attention and speed of psychomotor reactions.

Side effects:

From the central and peripheral nervous system: dizziness, a headache, weakness, motive concern, a nystagmus, a loss of consciousness, drowsiness, visual and acoustical disturbances, a tremor, a lockjaw, spasms (the risk of their development increases against the background of a hypercapnia and acidosis), paralysis of respiratory muscles, an apnoea, disturbance of conductivity on touch and motor fibers, respiratory depression (develops at subarachnoidal anesthesia more often).

From cardiovascular system: increase or a lowering of arterial pressure, bradycardia, arrhythmia, tachycardia - at introduction with a vasoconstrictor, a peripheral vazodilatation, a collapse, thorax pain.

Allergic reactions: skin rash, a small tortoiseshell (on skin and mucous membranes), a skin itch, a Quincke's disease, an acute anaphylaxis.

From an urinary system: involuntary urination.

From the alimentary system: nausea, vomiting, involuntary defecation.

From blood: methemoglobinemia.

Local reactions: at spinal anesthesia - a dorsodynia, at epidural anesthesia - accidental hit in a subarachnoid space.

Others: resistant anesthesia, hypothermia.

Interaction with other medicines:

Vasoconstrictors (Epinephrinum, метоксамин, Phenylephrinum) extend mestnoanesteziruyushchy action.

Cimetidinum reduces hepatic clearance of lidocaine (decrease in metabolism owing to inhibition of microsomal enzymes of a liver) and increases risk of development of toxic effects.

Reduces effect of anti-myasthenic medicines.

When processing the place of an injection of local anesthetic the disinfecting solutions containing heavy metals the risk of development of local reaction in the form of morbidity and hypostasis increases.

At use of mestnoanesteziruyushchy medicines for spinal and epidural anesthesia with guanadrely, guanetidiny, mekamilaminy, the trimetafana kamsilaty raises risk of the expressed lowering of arterial pressure and bradycardia.

Beta adrenoblockers slow down lidocaine metabolism, increasing its toxicity (decrease in size of a hepatic blood-groove).

Cardiac glycosides weaken cardiotonic effect.

Strengthens and extends effect of myorelaxation medicines.

At simultaneous use of lidocaine and somnolent and sedative medicinal sredstvvozmozhno strengthening of their oppressing action on the central nervous system.

At simultaneous use with narcotic analgetics the additive effect develops that is used when carrying out epidural anesthesia, however respiratory depression amplifies.

Simultaneous use with monoaminooxidase inhibitors (furasolidone, Procarbazinum, селегилин) increases risk of a lowering of arterial pressure.

Anticoagulants (including ардепарин sodium, далтепарин sodium, данапароид sodium, эноксапарин sodium, heparin, warfarin, etc.) increase risk of development of bleedings.

Contraindications:

Hypersensitivity to drug components; heavy bleedings, infection of the place of an estimated injection. A sick sinus syndrome, the expressed bradycardia, an atrioventricular block ІІ-ІІІ degrees, sinuatrial blockade, a WPW-syndrome, acute and chronic heart failure, cardiogenic shock, disturbances of intra ventricular conductivity, heavy arterial hypotension, retrobulbar introduction by the patient with glaucoma.

Overdose:

Symptoms: the first signs intoxicationsof - dizziness, nausea, vomiting, euphoria; then - spasms of mimic muscles of the person with transition to toniko-clonic spasms of skeletal muscles, psychomotor excitement, an adynamy, an apnoea, bradycardia, a lowering of arterial pressure, a collapse, a methemoglobinemia; when using at childbirth at the newborn - bradycardia, oppression of a respiratory center, an apnoea.

Treatment: the patient has to be in horizontal position; appoint oxygen inhalation. In cases of display of spasms enter intravenously 10 mg of diazepam. At bradycardia - m-holinoblokatory (atropine), vasoconstrictors (Norepinephrinum, Phenylephrinum). Dialysis is inefficient.

Storage conditions:

To store in the place protected from light at a temperature not above 30 °C. To store in the place, unavailable to children.

Issue conditions:

According to the recipe

Packaging:

Solution for injections of 20 mg/ml on 2 ml in ampoules.

5 ampoules place in a blister strip packaging from a film polyvinyl chloride.

1 or 2 blister strip packagings together with the application instruction and the scarificator ampoule or a knife ampoule place in a pack from a cardboard.

5 or 10 ampoules together with the application instruction and the scarificator ampoule or a knife ampoule place in a box from a cardboard with a corrugated insert.

When packaging ampoules with a point or a ring of a separation the scarificator or a knife ampoule do not put.