Talk:Local anesthetic

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Heirarchy of Articles

I have attempted to implement a relationship between some articles as follows:

Anesthesia
  General Anesthesia
  Regional Anesthesia
  Local Anesthesia
    Local Anesthetic
      Local Anesthetic Toxicity

I strongly recommend that someone take the time to edit the Adverse Effects section to combine and reduce Local Anesthetic Toxicity into a single sub-article. Anon lynx (talk) 14:35, 14 February 2008 (UTC)[reply]

Sodium Gated Channels in Lipid Membrade of Neuron

The following copied from Kosebamse talk page:

Hi, Kosebamse. Thanks for complimenting my contribution to local anesthetic. Unfortunately, I don't really know much about the topic besides what I touched on--that the targets are voltage-gated sodium channels. I could expand on the molecular details perhaps, but I suspect it's detail that most people wouldn't want to know. Do you disagree? 168... 01:09 Feb 14, 2003 (UTC)

Well, yes, to some degree. I'll be happy to do some more on the pharmacology and clinical uses, but my knowledge about the molecular mechanisms is rather patchy. So if you like you might contribute some details, perhaps one or two more paragraphs? And by the way, I'll move this to the article's talk page where people may look for it. Thanks for your help! Kosebamse

When I searched lidocaine binding on the Web I saw conflicting theories about how it affects Na+ channels, although I saw some agreement in as far as the view that there is a gating effect and not/not only pore occlusion. That's just lidocaine, though. 168... 18:53 Feb 15, 2003 (UTC)

There are several theories with respect to open/closed/inactive channels and even the lipid bilayer of the cell membrane is thought to be a target. However, there seems to be some agreement that the main action is occlusion of the Na+ channel somewhere near the pore at the cytoplasmic side. I believe that everything we discuss here is class effects and it doesn't matter much whether it's been studied on lidocaine or whatever. But I'm afraid I am leaving firm ground here and would be grateful for any enlightening comments. Kosebamse 23:55 Feb 15, 2003 (UTC)

History Section Proposed

We need a History section -- this page has some good information Local Anesthetics --Thoric 00:18, 23 Nov 2004 (UTC)

Anon_lynx common sense tells me that: 1. local = localized and can refer to any large or small area (region) Anon lynx (talk) 14:31, 14 February 2008 (UTC)[reply]

This article appears to me to be a less comprehensive article, and a duplication of the subject of Local anaesthesia L-Bit 3 July 2005 00:06 (UTC)

  • While I don't know the subject, the thing to do if that is indeed the case would be a redirect from one to the other. No VfD required. CDC (talk) 3 July 2005 00:42 (UTC)
  • Keep, expand. Different from Local anaesthesia, and if that is a valid topic then this should be also, with cross-reference links both ways. It is important for the article to show that it is not the same as local. --WCFrancis 4 July 2005 08:56 (UTC)
But, keep in mind I am not in the medical profession or by any means knowledgeable about anaesthesia. Make my vote Weak Keep for now. --WCFrancis 4 July 2005 09:00 (UTC)
Back to Keep, with restructuring. Looking for definitions makes me think that local anaesthesia is a subset of regional anaesthesia. Therefore, I suggest that the material in Local anaesthesia be moved to Regional anaesthesia and a redirect created from the local anaesthesia article. But, first, we must ask the age-old question - Is there a Doctor in the house?. --WCFrancis 4 July 2005 09:35 (UTC)


Keep Had I done some research before posting here, I would probably not have posted as VfD. Acccording to Oysten's website, local anaesthesia is indeed a subset of regional anaesthesia and so User:WCFrancis; you are correct. However, as Dr Oysten states, ".... many people use the phrase (local anaesthesia) loosely to include regional anaesthesia". That begs the question, if "Local" is more commonly used to refer to the medically correct term "Regional", and I would hazard a guess that "more commonly" should be read as "almost universally", then should "Local" be the main entry? I note also that the original "Regional" article spells anaethesia without the second 'A'. I have no idea if this is American spelling or a typo. So, I am giving up with this VfD and copying this whole section to the two discussion pages - "Regional" and "Local" in the hope that a medical person and/or a person better versed in Wiki procedures can clean up the issue. L-Bit 01:34, 10 July 2005 (UTC)[reply]

HELP, Does local anasthesia have any effect on mood and the brain?

The question above. ANY effect. Chiss Boy 17:26, 22 February 2007 (UTC)[reply]

This may be an appropriate discussion for the article Local Anesthesia unless you are asking about a particular anesthetic agent, in which case it may better be discussed in the article for that agent. Anon lynx (talk) 14:25, 14 February 2008 (UTC)[reply]

"The names of Amides contain an "i" somewhere before the -aine. Esters do not."

This doesn't seem to always be the case, because of dimethocaine, maybe it should be removed or qualified? I added several more going by this premise, but seeing as it doesn't seem to always be the case some I may have added might be incorrectly classed. Nagelfar (talk) 19:04, 8 January 2008 (UTC)[reply]

Physiology text from local analgesia

I was merging some text from local analgesia, and came across the following bulk of text (see box below). It seems it is rather an overkill of details, since, IMPOV, the Mechanism of action-section in this article already explains it pretty well, with links to related physiology articles for those who want to know more. However, if you find any important point that should be given here, feel free to complement the article with it. Mikael Häggström (talk) 08:47, 17 April 2011 (UTC)[reply]

To achieve conduction anesthesia a local anesthetic is injected or applied to a body surface. The local anesthetic then diffuses into nerves where it inhibits the propagation of signals for pain, muscle contraction, regulation of blood circulation and other body functions. Relatively high drug doses or concentrations inhibit all qualities of sensation (pain, touch, temperature etc.) as well as muscle control. Lower doses or concentrations may selectively inhibit pain sensation with minimal effect on muscle power. Some techniques of pain therapy, such as walking epidurals for labor pain use this effect, termed differential block.

Anesthesia persists as long as there is a sufficient concentration of local anesthetic at the affected nerves. Sometimes a vasoconstrictor drug is added to decrease local blood flow, thereby slowing the transport of the local anesthetic away from the site of injection. Depending on the drug and technique, the anesthetic effect may persist from less than an hour to several hours. Placement of a catheter for continuous infusion or repeated injection allows conduction anesthesia to last for days or weeks. This is typically done for purposes of pain therapy.

Pathophysiology

Reviewing the physiology of nerve conduction is important before any discussion of local anesthetics. Nerves transmit sensation as a result of the propagation of electrical impulses; this propagation is accomplished by alternating the ion gradient across the nerve cell wall, or axolemma.

In the normal resting state, the nerve has a negative membrane potential of -70 mV. This resting potential is determined by the concentration gradients of 2 major ions, Na+ and K+, and the relative membrane permeability to these ions (also known as leak currents). The concentration gradients are maintained by the sodium/potassium ATP pump (in an energy-dependent process) that transports sodium ions out of the cell and potassium ions into the cell. This active transport creates a concentration gradient that favors the extracellular diffusion of potassium ions. In addition, because the nerve membrane is permeable to potassium ions and impermeable to sodium ions, 95% of the ionic leak in excitable cells is caused by K+ ions in the form of an outward flux, accounting for the negative resting potential. The recently identified 2-pore domain potassium (K2P) channels are believed to be responsible for leak K+ currents.

When a nerve is stimulated, depolarization of the nerve occurs, and impulse propagation progresses. Initially, sodium ions gradually enter the cell through the nerve cell membrane. The entry of sodium ions causes the transmembrane electric potential to increase from the resting potential. Once the potential reaches a threshold level of approximately -55 mV, a rapid influx of sodium ions ensues. Sodium channels in the membrane become activated, and sodium ion permeability increases; the nerve membrane is depolarized to a level of +35 mV or more.

Once membrane depolarization is complete, the membrane becomes impermeable to sodium ions again, and the conductance of potassium ions into the cell increases. The process restores the excess of intracellular potassium and extracellular sodium and reinstates the negative resting membrane potential. Alterations in the nerve cell membrane potential are termed the action potential. Leak currents are present through all the phases of the action potential, including setting of the resting membrane potential and repolarization.

Cocaine as violating in vivo rules of "lipophilic / hydrophilic balance" due to "local anesthetic effect"

From here:

"This peculiarity, since called the local anesthetic effect, we now know was produced by the following mechanism: (see figure 2) The membrane of the axon (nerve trunk) is formed by a bimolecular layer of lipids, which possess hydrophilic protein layers on both sides. The local anesthetic is linked by its hydrophilic portion to the corresponding receiver of the nerve membrane and by its lipophilic portion to the other."

This shows a form of active transport *into* the CNS from water soluble to similarly lipid soluble conditions in the body by means of sodium channel blocking of sodium action potentials. Might this be applied in other ways besides "local anesthetic" conceivably?

Nagelfar (talk) 12:23, 7 August 2011 (UTC)[reply]

Halls

Does halls contain cough syrup? 45.221.82.44 (talk) 09:48, 15 December 2021 (UTC)[reply]

Ambroxol

As a sodium channel inhibitor and local anesthetic stronger than lidocaine, shouldn't ambroxol be listed here?

Kern KU, Weiser T. Topical ambroxol for the treatment of neuropathic pain. An initial clinical observation. Schmerz. 2015 Dec;29 Suppl 3(Suppl 3):S89-96. doi: 10.1007/s00482-015-0060-y. PMID: 26589711; PMCID: PMC4701773. —Sharavanabhava (talk) 06:06, 20 February 2024 (UTC)[reply]