Side effects of Lidocaine

Undesirable effects after the use of lidocaine need not occur, but they may occur with varying frequency depending on the dosage form. Lidocaine is usually well tolerated, and injections occasionally cause pain in the legs or a sudden drop in blood pressure. Rare side effects may include agitation and seizures, some patients report a numb tongue, dizziness or light-headedness.

If there is ringing in the ears, this is an early sign of a lidocaine overdose and should be treated. Cardiac arrhythmia may occur under lidocaine therapy and allergic reactions such as hives, shortness of breath and circulatory problems are also side effects of lidocaine. The medication should not get into the eyes or open wounds.

In this case it must be washed out thoroughly with water immediately. When used in the mouth and throat area, it should be noted that lidocaine causes numbness and thus increases the risk of bite wounds. In addition, there is a risk of swallowing, especially in children, as lidocaine impairs swallowing.

Allergy to lidocaine

In contrast to undesirable side effects, which are often caused by overdoses, allergic reactions occur even at very low doses of the drug. In many cases an allergy to lidocaine manifests itself in relatively harmless symptoms such as redness and local swelling. In rare cases, however, an allergic shock (anaphylactic shock) caused by Lidocaine may also occur.

It is therefore recommended that a sensitivity test (allergy test) be performed for people who are prone to allergies. Since many dosage forms contain other substances in the lidocaine preparations, a possible allergy to these additives should also be considered. In case of a known allergy, other local anaesthetics with the suffix -cain should also be avoided.

Interactions of Lidocaine

Lidocaine can be administered in different dosage forms. Interactions with other active ingredients usually only occur when a lidocaine solution is injected; local forms of application would have to be used for a very long time and in high doses to cause interactions. Drugs that influence the heart rhythm (such as calcium channel blockers and antiarrhythmic drugs) may, under certain circumstances, increase or decrease the effect of lidocaine on the heart action. The effect of lidocaine can be enhanced by simultaneous use of antihypertensive drugs (e.g. beta-blockers), whereas anti-epileptic drugs can reduce the effectiveness of lidocaine.