Lidocaine

Lidocaine is a common anesthetic or a pain reliever that is used by dentists and doctors. It has been combined in several ways to create new substances that are used as medicines. While lidocaine has been linked to several side effects, these cases are rare, and the benefits of the drug far outstrip the risks.

Properties
Lidocaine's basic properties are listed in the table on the right. It is an organic compound used as a local anesthetic. When in its solid form, it is a white or yellowish powder that can be somewhat hazardous to humans. Unscented and slightly acidic, if inhaled or ingested it can leave a bitter taste in the mouth. It can also cause some irritation or other health problems. While toxic in its solid form, it can be a great medical asset when used properly. Even though it can be hazardous to humans in its solid form, in its hydrochloride form lidocaine can be used by doctors to help patients. Lidocaine molecules are made up of 14 carbon atoms, 22 hydrogen atoms, 20 nitrogen atoms and one oxygen atom each, making it a relatively large molecule.

Synthesis
Since Lidocaine is man-made, it does not occur in nature. It was first synthesized by the Swedish chemist Nils Löfgren in 1943. His colleague Bengt Lundqvist tested the drug. He injected himself with the new anesthesia, and after many extensive experiments, they put it on the market in 1949. Lidocaine, both in pure and mixed forms, is very easy to find, and also easy to buy.

Uses
Typically, Lidocaine is used as a pain killer and to relieve pain, itching, and burning on the skin. It is also used as a local anesthetic, injected as dental anesthetic, or used in minor surgery. It is either applied topically, or injected into the body through a needle. It is used commonly as surface anesthesia to relieve pain on the skin, infiltration anesthesia (meaning it is injected into the skin), conduction anesthesia (meaning it is applied to a nerve, and as epidural anesthesia (meaning it is used in childbirth).

Side Effects
Although they are not very common, there have been several side effects reported due to use of lidocaine hydrochloride. These effects may be caused by excessive dosage, rapid absorption into the blood stream, unintentional injection into the blood stream, a hypersensitivity to the drug, or an idiosyncrasy or diminished tolerance of lidocaine HCL. The following side effects are those that are generally the most commonly reported.

Central Nervous System

Side effects that affect the central nervous system can be characterized by lightheadedness, nervousness, apprehension, euphoria, confusion, dizziness, drowsiness, ringing in the ears, blurred or double vision, vomiting, sensations of heat, cold, or numbness, twitching, tremors, convulsions, unconsciousness, respiratory depression, and not being able to breathe. These side effects may be very brief or may not occur at all, in which case the first sign of toxicity may be drowsiness, which then merges into unconsciousness and respiratory arrest.

Cardiovascular System

Cardiovascular side effects are usually depressant and are characterized by irregular heartbeat, abnormally low blood pressure, and cardiovascular collapse, which may lead to cardiac arrest.

Allergic

Allergic reactions can include hives, swelling or fainting. These reactions may occur as a result of sensitivity either to local anesthetic agents or to the methylparaben used as a preservative in the containers of lidocaine HCL. Allergic reactions as result of sensitivity to lidocaine HCl are extremely rare and, if they occur, can be managed by normal means.

While these are not the only side effects, they are some of the most common. It should also be remembered that side effects of drugs containing Lidocaine do not occur often enough to make them a worry.

Additional Information

 * Drugs & Medication Lidocaine Relationships Unlimited, accessed 2-5-11
 * Lidocaine Unknown author, Paramedicine.com, 2009
 * Lidocaine Chemical Structure Anne Marie Helmenstine, New York Times Company, 2011
 * Lidocaine Facts Unknown author, DrugBank.com, Updated on November 10, 2010
 * Lidocaine Unknown author, Bikudo.com, accessed 2-7-11
 * Look Chem: Lidocaine Unknown author, LookChem.com, 2008
 * 003146 Lidocaine Unknown author, Orygn.com, accessed 2-5-11
 * Side Effects Unknown author, RxList.com, last reviewed 1-10-11
 * Lidocaine and its Toxic Properties Savastru Liviu, Factoidz.com, Accessed 2-15-11
 * Lidocaine article Unknown author, Wikipedia.org, last modified February 8th, 2011