What is Lidocaine Hydrochloride?

M. Haskins

In its basic form, lidocaine hydrochloride is a white powder without smell and with a bitter taste that is used both in human and veterinary medicine. The drug is also known as lignocaine hydrochloride, and is used as a local anesthetic and to regulate certain medical problems related to heart rhythm. Injections of it are used to provide local anesthesia during various minor surgical procedures. It is also available in various topical preparations, such as gels, sprays, creams, and ointments that are usually applied to the skin or the mucous membranes. This drug was first manufactured in Sweden in 1943 and was then named xylocaine.

Lidocaine hydrochloride can be used in the form of a spray.
Lidocaine hydrochloride can be used in the form of a spray.

When used for anesthetic purposes, lidocaine hydrochloride works by blocking certain functions of the nervous system, inhibiting the transmission of pain impulses from the treated area to the brain. It is a fast-acting form of local anesthesia that often starts to work within five minutes. The effects wear off in a relatively short time, often a couple of hours, because the drug is quickly metabolized by the liver.

Nausea is one side effect of lidocaine hydrochloride.
Nausea is one side effect of lidocaine hydrochloride.

Gels, creams, and other topical treatments containing this compound are available without a prescription and can be used to relieve various kinds of itching, skin irritation, and pain. For example, lidocaine creams can be used to treat burns, sunburns, shingles, and jellyfish stings. It can also be used to relieve the pain of urethritis, a urinary tract inflammation. In hospitals, lidocaine jelly is used when a patient is intubated through the mouth or nose to numb the affected area when the tube is inserted.

Lidocaine creams may be used to treat sunburns.
Lidocaine creams may be used to treat sunburns.

This drug is also available in liquid form and is then often injected. An injection can be used to provide local anesthesia during minor surgical procedures like eye surgery, dental surgery, and throat surgery. It is also used to treat certain forms of heart arrhythmia, meaning conditions where the heartbeat is irregular because the chambers of the heart are not functioning properly. Lidocaine hydrochloride injections are only available by prescription and under medical supervision, as in a hospital, doctor's office, or medical clinic.

This compound has few side effects when used as a topical treatment, but they are more common when the drug is injected, and occur most often in the case of overdose. Possible side effects include itching, rash, breathing problems, nausea, and slow heartbeat. People over the age of 65 and those with various medical issues, such as kidney or liver problems, are more susceptible to adverse side effects from lidocaine injections.

People age 65 and older are more susceptible to adverse side effects from lidocaine injections.
People age 65 and older are more susceptible to adverse side effects from lidocaine injections.

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Discussion Comments


@nony - I wouldn’t go overboard on the Lidoderm patch. Try it out and see how it works. But long term, blocking pain receptors is not a good thing.

Some people prefer to compare treatments and I think that’s a good idea. You may want to try some other pain blockers, like NSAIDS first.

These are non steroidal drugs that a lot of people take for arthritis. Of course they have their own side effects too. But Lidoderm can result in rashes if you use it too long.

I know some people use it to treat back pain, and the prolonged exposure against the skin for up to eight hours a day can really cause you some problems in my opinion.


I suffered a potent insect stung in my finger once, which resulted in a lot of inflammation. It hurt badly and I needed both pain relief and for the inflammation to go down, because I work with computers all day and that was a typing finger!

Anyway, the doctor prescribed antibiotics and some lidocaine hydrochloride jelly. It worked quickly to relieve the itch. I had used some topical stuff but nothing was as potent as this jelly.

I would have to reapply it every few hours as the effect wore off. It made typing a little inconvenient to have that jelly on my finger but at least I could get my work done.


@sunnySkys - It's probably a good thing lidocaine gel isn't widely available over the counter. As one of the other commenters said, you can give yourself an overdose of lidocaine pretty easily.

Going out in the sun with a lidocaine patch is one way. Another way is covering too large of an area with lidocaine. I know a lot of people fail to read the warning labels on products, so I could see this happening pretty easily. At least if you get a lidocaine prescription from a doctor, the doctor will tell you how to use it.


@KaBoom - It's unfortunate that you get lidocaine side effects, but at least they don't last the entire time you're having dental work done. That would be pretty unpleasant.

I know lidocaine is used pretty frequently, but benzocaine is another anesthetic that's used in a lot of different things. In fact, benzocaine is used in a ton of different cough drops and some sore throat sprays you can get over the counter. From what I understand, there aren't that many lidocaine products available over the counter, but you can usually get stuff with benzocaine in it pretty easily.


@shell4life - Last time I was at the dentist getting a crown done, my dentist told me they use lidocaine for just about all dental procedures now. Even though everyone always thinks that dentists use novocaine, most dentists don't even use it anymore.

Every time I get dental work done, I usually experience a few side effects my dentists tells me are pretty normal. I get a little bit shaky and my heart starts beating a little bit faster. However, the effects usually go away after a few minutes.


@cloudel – My aunt also used a lidocaine patch for her shingles. Regions of her skin had become very sensitive, and the patches numbed them while keeping clothing and other objects from coming into contact with them, so it seemed like the ideal treatment.

However, my aunt didn't fully read all the warnings. You are not supposed to expose your patch to heat, and she stayed outside in the hot sun for half an hour.

When a lidocaine patch gets heated up, more of the drug than necessary can be released. She gave herself a lidocaine overdose on accident.

She became very dizzy and confused. Her vision was affected, and I knew that something was wrong. I took her patch off and took her to the emergency room, where she was treated for lidocaine toxicity.


My mother had a bad case of shingles last year, and her doctor prescribed her some lidocaine patches to help her deal with the pain. He gave her a long list of instructions for their use to help her avoid an accidental overdose.

She was allowed to wear as many as three patches at a time. She could cut them to fit over the area, so she didn't expose her unaffected skin to lidocaine. It was good for her to use only what was needed.

Since she followed all the instructions, she didn't have any problems with rashes or worse side effects. The patches blocked out the pain and made dealing with the condition so much easier. I'm sure the time it took for her to heal went by much faster, too.


I have had several teeth pulled in my lifetime, and the dentist has always given me a lidocaine shot. No one likes to see a big needle going toward their gums, but most dentists do all they can to ease the anxiety.

My dentist always rubs a numbing gel on my gums several minutes before he plans to inject the lidocaine. He lets me lie there in the chair, slowly going numb. He comes in to check on me, and if I still have any sensation when he pokes the area, he either puts more gel on or lets it set just awhile longer.

When it's completely numb, he injects the lidocaine. I do feel pressure during the shot, but it doesn't really hurt. It probably helps that I also have been wearing the laughing gas mask, so I don't care too much about anything at that moment!


I have been stung by jellyfish before, and I sure wished that I had lidocaine with me at the time. It would have numbed the intense pain that felt nearly unbearable.

All I had was baking soda, and I'm told that it helps keep the venom from doing further damage. I put it on my wet leg after scraping off the tentacles with a seashell.

There is nothing quite like lidocaine when it comes to pain relief, though. It totally numbs the area where you apply it. Next time I go to the ocean, I will be sure to pack some lidocaine cream.

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