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What is a Local Anaesthetic?

Tricia Christensen
Tricia Christensen
Tricia Christensen
Tricia Christensen

A local anaesthetic (or anesthetic) may be one of a number of medications delivered in a few different ways that provide numbing and pain relief to a targeted area of the body. Most people have experienced a local anaesthetic if they have ever visited the dentist. Injections of novocaine to numb the mouth are examples of local anesthesia, and, as might be noted, do a fairly good job of creating pain-free, if not fear-free, dental experiences. There are many other examples of local anaesthetics, what they do, and how they can be administered.

It might be easy to assume from the dental example that a local anaesthetic is always administered with a shot, but this is not true. There are some types placed directly on the skin, and dentists may use these in the mouth also. Since a shot of novocaine is not comfortable, many dentists prefer to first put a topical solution on the area where the shot will be given to numb the mouth so the shot is felt less. Topical anaesthetics might be the only treatment under other circumstances.

Cocaine was once used as a local anaesthetic.
Cocaine was once used as a local anaesthetic.

Exactly what a local anaesthetic is doing is often associated with creating numbness or reducing feeling. Through a variety of mechanisms, drugs that are considered local anaesthetics block the way that nerves work. This temporarily reduces sensation in areas that require some medical intervention. Sensation reduction can last for several hours and might only need reapplication if the medical intervention is ongoing, or if the anaesthetic is being used to address certain types of pain. It should be noted that there are weak anaesthetics available widely; these might treat conditions like tooth pain, sunburn or hemorrhoid pain and come in different topical application forms.

Weak local anesthetics can be used to treat sunburns.
Weak local anesthetics can be used to treat sunburns.

There is some dispute on terms related to local anaesthetic. These terms are regional and central. Regional anaesthetics are localized to a specific nerve and usually involve a single injection into the nerve. These are quite effective and can be used for a variety of surgeries, possibly in conjunction with other types of anesthesia that produce sleepiness.

A type of local anesthetic, an epidural can numb parts of the body from pain, such as during labor or surgery.
A type of local anesthetic, an epidural can numb parts of the body from pain, such as during labor or surgery.

Central anaesthetics may use a catheter or injection into the spine to produce total numbness from the waist down. The most classic example of this is the epidural, which many women in labor request for pain relief. Both regional and central anaesthetics tend to reach a wider area of the body than a local anaesthetic, though pain relief is still localized to a targeted area. All three types differ from general anesthesia, in which total consciousness is lost.

Local anaesthetics are often used for dental procedures.
Local anaesthetics are often used for dental procedures.

There are many different kinds of medicine that may be used to produce nerve-blocking response. As mentioned, novocaine is among these. Even more popular is the medication lidocaine. Cocaine used to be the local anaesthetic of choice, but today synthetic versions of it are preferred. Almost all local anaesthetics still reference cocaine with their last syllable.

Some mild local anesthetics, including pain relief spray, are made for occasional over-the-counter use.
Some mild local anesthetics, including pain relief spray, are made for occasional over-the-counter use.

Like most medications, some of these drugs cause adverse or even allergic reactions. Most of these reactions can be immediately addressed in the medical setting with drugs like epinephrine. Should people have experience an adverse reaction to a local anaesthetic in the past, they should get the name of the drug used. People should plan on updating files with their local doctor about reaction to the drug. They should also make certain to inform medical practitioners about the reaction prior to undergoing any other procedures in the future.

Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent WiseGEEK contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

Learn more...
Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent WiseGEEK contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

Learn more...

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    • Cocaine was once used as a local anaesthetic.
      By: HamsterMan
      Cocaine was once used as a local anaesthetic.
    • Weak local anesthetics can be used to treat sunburns.
      By: Rostislav Sedlacek
      Weak local anesthetics can be used to treat sunburns.
    • A type of local anesthetic, an epidural can numb parts of the body from pain, such as during labor or surgery.
      By: chanawit
      A type of local anesthetic, an epidural can numb parts of the body from pain, such as during labor or surgery.
    • Local anaesthetics are often used for dental procedures.
      By: Vladimir Melnik
      Local anaesthetics are often used for dental procedures.
    • Some mild local anesthetics, including pain relief spray, are made for occasional over-the-counter use.
      By: Nikki Zalewski
      Some mild local anesthetics, including pain relief spray, are made for occasional over-the-counter use.