Mode of action of lidocaine

Lidocaine acts as a local anesthetic on our nerves. A nerve receives a stimulus such as pressure or temperature through a number of nerve endings and transmits this signal to the spinal cord or brain, where we perceive the stimulus as pain, for example. This transmission takes place with the help of minerals such as potassium and sodium.

Lidocaine influences the sodium channels and thus prevents the transmission of the stimulus. So for the moment when Lidocaine is effective, the pain is not perceived, the area is numbed. Such sodium channels are also present in the heart, where they are important for the heart rate and rhythm. If Lidocaine blocks these channels, the heartbeat slows down and the rhythm can normalize. This is used in the use of lidocaine for cardiac arrhythmias.

Lidocaine as a drug

Lidocaine in isolation is not known as a drug because, unlike cocaine, it does not cause intoxication and contains no addictive components. However, drug dealers use lidocaine to stretch cocaine. This is done because the purity of cocaine is often tested by numbing the gums and thus giving the user a particularly pure substance by adding lidocaine.

In addition, the taste of lidocaine is similarly bitter as the taste of cocaine and is therefore not recognizable to the consumer. Due to the undesirable side effects of lidocaine, such as cardiac arrhythmia, such an admixture can be life-threatening for the user. Particularly among users who use cocaine intravenously, there is an increase in the number of deaths from cardiac arrest caused by an overdose of lidocaine. However, since cocaine has similar side effects, it is difficult to distinguish which deaths are caused by the diluent lidocaine and which are caused by the cocaine itself. Approximately one third of cocaine samples seized contain lidocaine.

When should lidocaine not be used?

Local anesthesia is usually a very gentle form of pain elimination. However, lidocaine must not be administered if the patient already has a weak heart muscle or low blood pressure.Certain cardiac arrhythmias (such as AV block II degree), shock, epilepsy and heart attack are also contraindications for the use of lidocaine. Lidocaine may cause allergic reactions and should not be used if hypersensitivity to lidocaine or a similar substance already exists.

In addition, infections at the site of local anesthesia are contraindications to lidocaine. Patients with severe kidney or liver disease should receive lidocaine only in exceptional cases, as an increased concentration of the active substance in the blood may occur. During pregnancy, lidocaine should only be used as an injection solution in exceptional cases and under medical supervision, as it can harm the child via the placenta.

A superficial application is harmless during pregnancy. Lidocaine can also be used during breastfeeding, but it should not be applied to the nursing breast. External application of lidocaine as a cream, gel or ointment is safe for children and may be used.

However, if lidocaine is to be injected, it should only be used in children under medical supervision. There are special restrictions on the use of lidocaine in the spinal cord. Special caution is required in patients with blood clotting disorders, increased intracranial pressure or reduced blood volume.