Lidocaine is a widely used local anesthetic that temporarily blocks nerve signals to numb areas of the body and alleviate pain. While beneficial in its intended applications, consuming it orally poses significant dangers. This article explores its appropriate uses and the risks of ingestion.
Understanding Lidocaine’s Purpose
Lidocaine functions as a local anesthetic by stabilizing nerve cell membranes, which inhibits the flow of sodium ions necessary for nerve impulse transmission. This action prevents pain signals from reaching the brain, leading to a localized numbing effect.
It is commonly found in topical creams, gels, patches, and injectable solutions. Medical professionals use lidocaine for various procedures, such as numbing skin before minor surgery, dental work, or relieving discomfort from conditions like sunburn or shingles.
Viscous lidocaine solutions also numb the mouth and throat for certain medical procedures or to alleviate pain from oral sores. These applications are designed for localized effects with minimal systemic absorption, ensuring safe and effective use.
The Dangers of Oral Lidocaine Ingestion
Ingesting lidocaine is dangerous because it leads to rapid systemic absorption, entering the bloodstream through the digestive tract. This contrasts sharply with its intended topical or injectable uses, where absorption into general circulation is limited and controlled. When swallowed, lidocaine bypasses these controlled mechanisms, quickly reaching high concentrations.
The liver typically metabolizes lidocaine through “first-pass metabolism,” which reduces the active drug reaching systemic circulation after oral intake. However, large quantities can overwhelm this capacity, leading to unsafe blood levels. Even topical concentrations are too potent if consumed internally, resulting in severe, life-threatening effects on major body systems.
Signs of Lidocaine Toxicity
When a toxic amount of lidocaine is absorbed, it produces symptoms primarily affecting the central nervous system (CNS) and cardiovascular system. Early CNS signs include lightheadedness, dizziness, confusion, and a metallic taste. Individuals might also experience ringing in the ears (tinnitus), blurred vision, or numbness around the mouth.
As toxicity progresses, more severe CNS symptoms can manifest, such as tremors, muscle twitching, slurred speech, and agitation. In serious cases, seizures can occur, which may be followed by CNS depression, leading to drowsiness, unconsciousness, or even coma.
Cardiovascular effects are also a concern, including changes in heart rate (slow or fast), low blood pressure, and irregular heart rhythms. In severe instances, lidocaine toxicity can lead to cardiac arrest, posing a life-threatening emergency.
Responding to Accidental Ingestion
If someone has ingested lidocaine, immediate action is crucial. Call emergency services, such as Poison Control at 1-800-222-1222 or 911, for guidance based on the specific circumstances.
Do not induce vomiting unless explicitly instructed by a medical professional. Keep the lidocaine product container nearby for essential information. While awaiting help, monitor the individual’s condition closely for changes in consciousness, breathing, or other symptoms. Prompt medical attention is vital to manage potential toxicity and ensure the best outcome.