Mepifrin

Mepifrin contains the component mepivacaine hydrochloride - a local amide anesthetic with a rapid development of anesthetic effect. This effect is associated with a short-term suppression of cardiac conduction and neural conduction within motor, autonomic and sensory fibers.

Used when performing dental operations. The analgesic effect develops very quickly - after 1-3 minutes - and is very pronounced. There is also good local tolerance. [1]

Indications Mepifrin

It is used for conduction or infiltration dental anesthesia .

It is used in the case of simple operations for the extraction of teeth , during the preparation of the oral cavity and the processing of the dental stump for the implementation of the restoration and the installation of orthopedic systems.

It is especially recommended for persons who cannot use vasoconstrictor substances.

Release form

The release of the therapeutic element is realized in the form of an injection liquid, inside cartridges or ampoules with a volume of 1.7 ml - 10 cartridges or 5 ampoules inside a cell pack. Inside the box there are 5 packs of carpules or 2 packs of ampoules.

Pharmacodynamics

The drug acts by blocking stress-dependent Na channels in the area of the neuronal fiber wall. At first, the substance passes through the nerve wall as a base, but is activated in the form of the mepivacaine cation only after the re-attachment of the proton occurs.

In the case of a low pH value (for example, inside inflamed areas), only a small particle is present in the basic form, due to which the analgesic effect can be weakened. [2]

The duration of the effect in the case of pulpal anesthesia is at least 20-40 minutes, and in the case of soft tissue anesthesia - in the range of 45-90 minutes.

Pharmacokinetics

Mepivacaine is absorbed in large volumes and at high speed. The protein binding index is in the range of 60-78%. The half-life is about 2 hours.

The level of the distribution volume of the injected substance is 84 ml, and the clearance rate is 0.78 l / minute.

Metabolic processes of mepivacaine are carried out inside the liver; excretion of metabolic components is carried out by the kidneys.

Dosing and administration

It is prescribed exclusively for anesthesia in dental procedures.

To achieve the required analgesic effect, it is necessary to use the minimum amount of a substance capable of providing such an effect. For an adult, this dosage is usually in the range of 1-4 ml.

A child over 4 years old with a weight of 20-30 kg is assigned portions within 0.25-1 ml; a child weighing 30-45 kg - within 0.5-2 ml.

In the elderly, an increased plasma index of Mepifrin may be noted - due to poor distribution and weak metabolic processes. The likelihood of accumulation of a substance increases especially in the case of repeated / additional injections. A similar effect can be observed in the case of systemic weakening of the patient and with exacerbation of hepatic / renal dysfunction. In this case, it is necessary to reduce the dosage (use the minimum volume that provides the required anesthesia). The portion sizes of drugs for people with certain pathologies (angina pectoris or arteriosclerosis) are reduced in the same way.

For an adult, the maximum allowable portion is 4 mg / kg. In this case, a person weighing 70 kg can enter no more than 0.3 g of mepivacaine (10 ml of medicinal solution).

For a child over 4 years old, the portion is selected taking into account his weight and age, as well as the duration of the procedure. Do not administer more than 4 mg / kg of the drug.

Usage scheme.

For the procedure, special reusable cartridge syringes are used. Before the injection of the drug, the carpool plug, which is pierced with an injection needle, must be wiped with alcohol for disinfection.

It is forbidden to process ampoules or carpules with any solutions. Also, it is forbidden to mix injectable liquid with other drugs inside one syringe.

To prevent the introduction of a substance into the vessel, a thorough aspiration test must be performed; it should be taken into account that a negative result of such a test does not guarantee the absence of the likelihood of accidental ingress into the vessel.

The medicine is injected at a rate of no more than 0.5 ml in a 15-second interval (corresponds to the 1st ampoule / cartridge per minute).

Many common manifestations associated with accidental injection of drugs into the vessel can be prevented by correctly performing the injection: after aspiration, 0.1-0.2 ml of Mepifrin is injected at a low speed, and then (after at least 20-30 seconds ) slow application of the residues of the substance.

If after the completion of the procedure, a solution remains inside the ampoule / cartridge, it should be disposed of. It is forbidden to use the remains of the medicinal liquid for other patients.

• Application for children

Cannot be administered to persons under 4 years of age.

Use Mepifrin during pregnancy

Clinical testing of mepivacaine during pregnancy has not been performed. Animal testing does not allow determining the effect of a substance on pregnancy, fetal development, childbirth and postnatal development.

Mepivacaine can cross the placenta. There is a possibility that with the introduction of mepivacaine in the 1st trimester, the risk of anomalies in the development of the fetus may increase, therefore, at an early stage of gestation, it is used only if it is impossible to use other local anesthetics.

There is no information about what volumes of the drug are excreted in breast milk. If you need to use Mepifrin during lactation, you can resume breastfeeding after about 24 hours from the moment of its use.

Contraindications

Among the contraindications:

• the presence of severe intolerance to local amide anesthetics;
• a history of malignant hyperthermia;
• severe disorders of AV conduction, in which a pacemaker is not used;
• epilepsy that cannot be controlled by medicinal methods;
• having a decompensated form of OCH;
• intermittent porphyria in the active phase;
• very low blood pressure.

Side effects Mepifrin

Negative symptoms developing in the central nervous system.

Among the manifestations are headaches, tremors, suppression or excitement of the activity of the central nervous system, speech or swallowing disorder, euphoria, metal taste, anxiety and nervousness. In addition, yawning, ear noise, weakening of consciousness, anxiety, dizziness and tremors are noted, as well as logorrhea, drowsiness, impaired vision, nystagmus and diplopia. Feelings of cold / heat / numbness, convulsions, seizures and disturbances of consciousness may appear, as well as a decrease and arrest of the respiratory process, loss of consciousness and a coma.

In the event of the development of such disorders, the patient is laid horizontally, oxygen ventilation is performed, and in addition, his condition is constantly monitored in order to prevent a worsening of the situation (the appearance of convulsions with further suppression of the central nervous system). Symptoms of arousal may be short-lived or not appear at all; in this case, the first manifestation may be drowsiness, turning into fainting and respiratory arrest. Often, the development of drowsiness after the use of mepivacaine is considered an early symptom of an increase in the blood count of the drug, which develops due to too rapid absorption.

Dysfunctions of the CVS.

Often, there is a suppression of the cardiovascular system, in which bradycardia occurs, the level of blood pressure decreases, which can provoke a collapse, as well as insufficiency of the function of the cardiovascular system, due to which cardiac arrest can occur. In addition, the following clinical symptoms are possible: cardiac conduction disorder (AV block), tachycardia and cardiac arrhythmia (ventricular extrasystole or fibrillation). Such signs can provoke cardiac arrest.

Such manifestations of suppression of the cardiovascular system are often associated with a vasovagal action, especially when the patient is in a standing position. But sometimes such disorders arise from the influence exerted by the drug. If prodromal symptoms (dizziness, change in pulse readings, sweat and weakness) were not immediately recognized, convulsions, cerebral hypoxia of a progressive type, or severe dysfunction of the CVS may develop.

In case of insufficient blood flow or auxiliary procedures, intravenous infusion and (in the absence of contraindications) the use of vasoconstrictor agents (for example, ephedrine) may be required, if necessary.

Respiratory disorders.

Tachypnea, and also bradypnea, which can cause apnea.

Allergy symptoms.

Usually, allergy symptoms when using mepivacaine appear only occasionally and are associated with severe intolerance. Among them, urticaria, anaphylactoid manifestations, rash, swelling, fever, Quincke's edema and anaphylaxis. As with the introduction of other local anesthetics, anaphylactic signs in this case appear only occasionally. Symptoms may come on suddenly and in an active form; the dosage is often not related to the size. The appearance of local swelling or swelling is possible.

Problems with the digestive tract.

Vomiting or nausea develops.

In case of the appearance of side signs, it is necessary to cancel the use of the local anesthetic.

Overdose

Intoxication due to an overdose of a local anesthetic can develop in two cases: immediately, if an accidental intravascular injection has occurred, or later, if an excessively large portion of the medication was injected. Such negative manifestations take the form of violations of the function of the CVS or the central nervous system.

Among the signs associated with the influence of the active element mepivacaine:

• CNS lesions: mild disorders - tachypnea, anxiety, metal taste, anxiety, dizziness and tinnitus. More severe disorders - muscle cramps or convulsions, respiratory paralysis, drowsiness, tremors, and coma;
• active lesions of the CVS: bradycardia, a decrease in blood pressure values, cardiac arrest and cardiac conduction disorders;
• active disorders associated with the work of the gastrointestinal tract: vomiting or nausea.

If negative symptoms appear, the administration of local anesthetic should be canceled.

It is necessary to control and maintain respiratory processes, intravenous and oxygen access, as well as blood flow processes. If the patient develops myoclonus, oxygenation and benzodiazepine injection should be performed.

In case of an increase in blood pressure values, it is necessary to raise the patient's upper body vertically, and also, if necessary, apply nifedipine sublingually.

When convulsions appear, it is necessary to monitor the patient so that he does not get injured, and in addition, if necessary, inject diazepam intravenously.

With a decrease in blood pressure, the patient is placed horizontally, and, if necessary, an intravascular infusion of saline solution is performed and vasoconstrictor agents are injected (intravenous administration of cortisone or epinephrine).

In the case of bradycardia, intravenous atropine is used.

If the patient develops anaphylaxis, medical attention should be called, and before her arrival, intravenous saline solutions should be administered. If necessary, it is administered intravenously by the method of cortisone and epinephrine.

In case of cardiac shock, it is necessary to raise the patient's upper body to an upright position and call for medical attention.

When the activity of the CVS stops, an indirect cardiac massage, mechanical ventilation is performed, and resuscitation actions are also performed. In addition, you need to call an ambulance.

Interactions with other drugs

Agents that block the activity of Ca channels, and β-blockers potentiate the suppression of myocardial contraction and conduction. When using sedatives in order to weaken the feeling of fear, it is necessary to lower the dosage of Mepifrin, since it, like sedative medicines, has a suppressive effect on the central nervous system.

With the use of anticoagulants, the likelihood of bleeding may increase.

In people who are taking antiarrhythmic drugs, there may be a potentiation of the symptoms of negative reactions when using mepivacaine.

Toxic synergism can be observed when the drug is used with sedatives, ether, central pain relievers, thiopental and chloroform.

Storage conditions

Mepifrin should be kept out of the reach of children. Do not freeze the medicine. Temperature indicators - no more than 25 ° С.

Shelf life

Mepifrin is allowed to be used within a 3-year period from the date of sale of the medicinal product.

Analogs

Analogues of drugs are the substances Mepivastezin, Ultracaine with Bucaine hyperbar, Emla and Articaine, and in addition, Omnikaine with Brilocaine-adrenaline, Lidocaine hydrochloride and Versatis.