Local Anesthetic
Wiki Index
Note that this is written in the context of use in electrolyisis and pellet implants for HRT.
https://en.wikipedia.org/wiki/Local_anesthetic - "A local anesthetic (LA) is a medication that causes absence of pain sensation. In the context of surgery, a local anesthetic creates an absence of pain in a specific location of the body without a loss of consciousness, as opposed to a general anesthetic. When it is used on specific nerve pathways (local anesthetic nerve block), paralysis (loss of muscle power) also can be achieved."
Related wiki pages
Topical Anesthetics
EMLA cream is applied to the skin and usually covered with a plastic food wrap. Its the weakest topical anesthetic I've come across. Its a 5% emulsion containing 2.5% each of lidocaine/prilocaine. Some find it helps, other find it does nothing.
Topical anesthetics
Be careful using topical anesthetics as a couple of women died in the USA using them, and covering and wrapping heir entire legs and wrapping them in preparation or laser hair removal. And some topical anesthetics are far stronger than the ones they used. It's probably extremely dangerous to use strong topicals on large body areas (ie laser or entire face); keep it to the minimum possible.
Its probably a good idea to test these stronger topical anesthetics on a small patch a patch of skin before using them on your face. Some of them can cause irritation to sensitive skin.
A common formulation of topical anesthetic is BLT cream, containing Benzocaine 20%, Lidocaine 6%, and Tetracaine 4%. The percentages seem to vary slightly, but there's a limit of 30% total, I believe set by the PCCA.
Another less common, but more powerful variation, LT cream with 23% Lignocaine, Tetracaine 7% (again note the limit of 30%).
The more lidocaine the more effective the topical anesthetic will be, but unfortunately lidocaine is toxic and the stronger formulations are more dangerous. Try to use weakest one that works and cover as little area as possible. People have ended up in hospital due to lidocaine.
Apart from safety lidocaine is often mixed with other topical anesthetics as its quite slow to take effect. This is not necessarily a problem with electrolysis, if you're prepared to wait.
An ingredient sometimes seen in topical anesthetics is Dimethyl sulfoxide (DMSO) at around 10%. This chemical transports anesthetics through though the skin, plus whatever else happens to be on your skin, so make sure everything is very clean (and no soap residue). Its also a strong solvent, dissolving many plastics and rubber, which you don't want to transported through your skin. Note that because DMSO increases the concentration of lignocaine in your body it also increases the risk. Higher concentrations of DMSO are presumably more effective, but can/will cause severe skin irritation/burns. You may get away with 20%, but maybe not. Not too surprising when you realise that DMSO is also used as paint stripper.
Dr Powers topical anesthetic (see here). Its unknown how effective this is compared to other strong topical anesthetics. He keeps changing it so the below will be out of date
Ketamine 10%+DMSO 10%+Gaba 6%+Amitriptyline 2%+Baclofen 1%+Cyclo 1%+Diclo 1%+Lido7% +Tetra2%+Benzo5%
SIG: Apply 90 minutes before procedure, 30 minutes before procedure, and 15 minutes before procedure. Limit to 100 square cm treatment area.
This stuff shames EMLA, however you cant apply it to your whole body at once as its literally Ketamine and DMSO and well....yeah that would be unwise. Limit to treatment zone only and you're fine. One patient abused it and coated their entire anterior thorax in it and didn't have a good time.
I've never heard of it in practice, but according to papers Epinephrine (adrenaline) can be added to topical anesthetics to extend the duration of its effect (I've been refused this on the grounds that its too dangerous). I would guess that as with injections of lidocaine it also increases the allowable dosage. See Alster 2013.
Epinephrine or another adrenergic agonist is often added to the local topical agent in order to prolong the anesthetic effects by increasing vasoconstriction and decreasing the rate of systemic absorption. Vasoconstriction increases the duration of time the agent is in contact with the nerve fibers; thus, prolonging the anesthetic effects
Note: Need to look into Phenylephrine which seems to be another vasoconstrictor. See here.
reddit
Prep School Daily
Papers
- 2022 - Lidocaine Toxicity by Klaus D. Torp; Eric Metheny; Leslie V. Simon - "All sexes are affected equally by lidocaine toxicity. Patients who are likely to be more susceptible to local anesthetic toxicity are patients at the extremes of age and women who are pregnant. Rates of severe systemic toxicity (seizures with or without cardiac arrest) occur on the order of 1:10,000 for epidurals and up to 1:2000 for peripheral nerve blocks, depending on the type of block. Patients under sedation at increased risk."
- 2020 - Systemic Adverse Events Associated with Compounded Topical Pain Products by
- 2017 - Comparative Study of Compounded Anesthetic Benzocaine/Lidocaine/Tetracaine (BLT) Cream with and without Abrasive Particles - "The study demonstrated that subjects experienced a higher mean pain level (but not statistically significant) when using the BLT with smooth texture compared to the BLT with abrasive particles when applied before HA dermal filler injection."
- 2015 - Lidocaine-Induced Methemoglobinemia: A Clinical Reminder by Mark Barash , Keith A. Reich and Dennis Rademaker - "Methemoglobinemia, or excessive levels of methemoglobin (MetHb) in the blood,1 is a rare and unusual complication associated with lidocaine use, and many clinicians—particularly those who infrequently use lidocaine or similar compounds—may be unaware of this potentially fatal condition."
- 2014 - Analgesic effects of topical ketamine by D J Kopsky, J M Keppel Hesselink, A Bhaskar, G Hariton, V Romanenko, R Casale
- 2013 - Review of Lidocaine/Tetracaine Cream as a Topical Anesthetic for Dermatologic Laser Procedures by Tina Alster
- 2012 - Comparison of five commonly-available, lidocaine-containing topical anesthetics and their effect on serum levels of lidocaine and its metabolite monoethylglycinexylidide (MEGX)
- 2011 - Immediate vesicular eruption caused by topical 23% lidocaine 7% tetracaine ointment in a patient scheduled for laser therapy: a new adverse drug reaction. - its probably a good idea to test a small patch of topical anesthetic before first use.
- 2008 - Benzocaine and lidocaine induced methemoglobinemia after bronchoscopy: a case report by Sophie Kwok, Jacqueline L Fischer, and John D Rogers
- 2006 - Systemic Toxicity From Topically Applied Lidocaine in Conjunction With Fractional Photothermolysis - "Although the use of topical lidocaine is considered relatively safe, instances of cardiotoxic and neurotoxic adverse events have been reported to occur."
Other publications
- 2020 - Compounded Topical Pain Creams: Review of Select Ingredients for Safety, Effectiveness, and Use., chapter from Compounded Topical Pain Creams Review of Select Ingredients for Safety, Effectiveness, and Use(2020)
- 2017 - Local Anesthetics in Cosmetic Dermatology
- 2015 - Topical Ketamine: Potential for Serious Abuse? in Medpage Today, "A woman accidentally overdosed on topical ketamine after putting an empty tampon applicator covered in the dissociative anesthetic in her rectum, according to a case study presented here. The 34-year-old, who worked in a podiatry office, said she had heard from a pharmaceutical representative that ketamine, a pain killer that has a history of misuse for its hallucinogenic effects, isn't heavily regulated ... The ketamine compound cream contained 10% ketamine, 6% gabapentin, 2% baclofen, 2% diclofenac, and 2% lidocaine."
reuters
pharmacists advancing health care
the dermatologist
HairTell
- FDA warns topical anesthetic makers after deaths in 2006 - "On December 4, 2006, the US Food and Drug Administration (FDA) sent out five warning letters to compounding pharmacies regarding the sale of compunded topical anesthetics. These products are sometimes used for hair removal. According to FDA, “There have been at least two non-fatal reactions and two deaths attributed to the use of compounded topical local anesthetic creams containing high doses of local anesthetics.”"
Other
Transdermal Bases
The topical anesthetic drugs are mixed into a base cream/gel, for example PLO gel. There's a range of these available with different properties and some are more suitable than others.
https://www.pccarx.com/Blog/2-tips-for-compounding-with-lidocaine-and-lidocaine-hcl - "Certain bases should not be used with the salt forms of the “‘caines,” such as lidocaine, tetracaine and benzocaine. For example, VersaBase® Gel (PCCA #30-3656) can only hold approximately 2% maximum salt (HCl) load, and Plasticized™ Base (PCCA #30-3211) has a low salt-load capacity as well. PCCA formulas provide guidance on which PCCA bases will hold certain combinations and concentrations of anesthetics."
Examples
Papers
Stripping the Skin
https://www.pccarx.com/Blog/lidocaine-vs-lidocaine-hci3 - *"A consideration for topical anesthesia prior to a pain stimulus is to focus on the application procedure. A technique called “stripping the skin” removes the top layers of dead skin cells as well as some sebum and triglycerides on the surface and, if done correctly, can dramatically increase onset of anesthesia. The first step is to scrub the skin vigorously with ethyl alcohol. Next, apply the compound to the surface followed by occlusion. Some prescribers recommend occlusion for 30 minutes, depending on the situation."
- Usefulness of Pressure-Sensitive Adhesives as a Pretreatment Material before Application of Topical Drug Formulations and a Peeling Tape for Excess Stratum Corneum Layers by Keisuke Kikuchi, Hiroaki Todo, and Kenji Sugibayashi, pdf here - "We prepared new PSA (PSA-A, -B) tapes with adequate adhesive properties by modifying the composition and preparation methods of conventional PSA cellophane tapes such as Cellotape® or Scotch Tape...Pretreating skin with PSA-A, in particular, can be used to markedly enhance skin permeation; the enhancement ratio of the skin permeation of lidocaine was approximately 22 times higher than that through intact skin. PSA-A can also be used to increase the skin concentration of topically applied chemical compounds." - its not clear this would be useful for anesthesia during hair removal as tape may remove the hairs before they can be treated.
Suppliers
Search for BLT cream in your country, or ask a compounding pharmacy (you'll probably need a prescription).
USA
Australia
Injectable
Pregabalin
https://en.wikipedia.org/wiki/Pregabalin - "Pregabalin, sold under the brand name Lyrica among others, is an anticonvulsant and anxiolytic medication used to treat epilepsy, neuropathic pain, fibromyalgia, restless leg syndrome, and generalized anxiety disorder. Its use in epilepsy is as an add-on therapy for partial seizures. When used before surgery, it reduces pain but results in greater sedation and visual disturbances. It is taken by mouth."
reddit
- Fell Asleep During Electrolysis by alisonchiou
in 2021 - "That Dr.P's custom pain cream is epic. I took 300mg of Pregabalin 2 hours before the procedure and drank some coffee to activate it, then I used the pain cream as directed. ... Pregablin is used to treat nerve and muscle pain. I used it when I got shingles and it works so much better then oxycodone for that specific type of pain. Dr. P's pain cream contains Gabapentin, which is the same class of drug as Pregabalin, so I experimented with it. I tried a session with Dr.P's cream with Hydrocodone, and a second session with cream with Pregablin. It seems Pregablin works better personally for me. I drink 6-7 cups of coffee per day, and when I was on Pregablin I accidentally discovered coffee somehow activates the drug and modifies its effect and it introduces a state of calmness and disassociation. Basically I am attacking the pain from both inside and outside. Not too sure it will work without the typical cream. The cream is doing most of the heavy lifting, I think Pregablin orally simply made the pain slightly less and introduce calmness for the session. I was super relaxed and comfortable. lease be careful. You can get addicted to Pregablin and withdraw symptom allegedly is pretty awful. When I was using it for shingles I made sure I taper off it slowly and I was okay."
Injections
Lidocaine injections are somtimes used for electrolysis, always for hormone pellet implants, and many other minor surgcial procedures.
Some electrologists work near a dentist who's prepared to administer dental blocks that will numb the upper lip and mouth area. The upper lip is often the most painful area, so this can be a great help. The area of effect from a dental block is quite limited, and while is possible to administer (infiltrate) local anesthetics elsewhere into the skin a dentist is not qualified to do so and will refuse.
Drugs used by dentists are lidocaine and articaine, optionally with epinephrine/adrenaline. Articaine is longer lasting and stronger than lidocaine (I don't know why its not standard). Preferably epinephrine is be used as it restricts the blood flow in the area making it last longer and reducing bleeding. If you have epinephrine you may start shaking and may find it difficult to stand for a short while afterwards.
It is possible (and effective) to inject (infiltrate) local anesthetic into the skin elsewhere in the face, but a dentist is not qualified to do so and will refuse (in Australia). Again there are not many places that can offer this service. In this case lidocaine is injected subcutaneously, about 3-5mm deep.
Lidocaine is normally safe (not always, hence the doctor) up to 0.3 mg per kg of body weight (i.e. 30 mg for a 100 Kg person), and when mixed with epinephrine the limit is 0.7mg per Kg. Injectable lidocaine is normally supplied in vials or ampules at either 10 or 20 mg/mL. The safe limit is therefore quite a small volume (even if its mixed with epinephrine), and well below what would be required for full facial clearance.
Lidocaine can be diluted with saline for electrolysis. This has the advantage that larger areas can be safely anaesthetised (due to the lower dosage of lidocaine). Presumably the chance of having an adverse reaction would also be reduced.
Lidocaine can to at diluted (to at least 1 part of 2% lidocaine to 7 parts saline) for electrolysis. When buffering with sodium bicarbonate to reduce injection pain (see implants/pellets) it is mixed according to the volume of lidocaine used, not the total volume including saline.
The ratio of sodium bicarbonate to lidocaine recommended in papers is usually 1:10, but it varies down to about 3:1. Perhaps the acidity of the lidocaine used varies? It its dangerous to inject too much sodium bicarbonate, but I don't currently know what the limit is.
If you're having long electrolysis sessions and find this all stressful, Zolpidem (Ambien) is quite a good drug to relax. It's quite strong (you might fall asleep), but only lasts about 4 hours (I'm not sure when its safe to drive afterwards). Most benzodiazepines last much longer and you'd likely be affected after the session is over. These are prescription drugs.
HairTell has an interesting post with a video of anasthetic injection for electrolysis, referring to the YouTube video Electrolysis For Men Starring Howard Paul Shore Wednesday, March 2nd, 20161 by HOWARD SHORE in 2016. The electrologists on HairTell are highly critical of the electrolysis tecnique, but I notice the lidocaine injection techniquie is also very poor.
- After the first injection subsequent injections should start from within the numbed area, then working out from withing the numbed area so that there's no additional pain. Instead she just picks lots of different places, maximising pain.
- The injections are performed at a very low angle, which increases pain by going through the maximum number of nerves. The first injection should be done at a 90° angle.
- Given the type of syringe, which looks like a dental syringe with cartridges, there's very little chance the lidocaine is buffered, increasing pain. It also won't be diluted, limiting the length of the session due to lidoaine toxicity.
- Rub the injected area afterwards to make it more effective.
reddit
- Frightening experience with Dr. Zukowski by birdsandsnakes in 2023 - Yesterday, I went for high volume hair removal at the Cirine Hair Removal. They're associated with the Zukowski Center, and Dr Zukowski gives medical support — the deal is, he sedates you and gives you lidocaine injections to numb your face, and then they do a very long electrolysis session. I had a really scary experience. Shortly after my third set of lidocaine injections, I'd gone for a bathroom break, when suddenly I found myself disoriented, losing control of my limbs, having a hard time walking, seeing double, and struggling to put sentences together. I made it out of the bathroom and asked an electrologist to call 911 — I could no longer use my phone to do it myself — but they refused. Instead, they called Dr Zukowski back. He tried to convince me I was having a panic attack. (I've had panic attacks. This was not a panic attack.) At this point, my arms and legs were twitching uncontrollably, and I couldn't stand or walk without help. He insisted that this was my fault, and that I'd feel better if I relaxed. Eventually, he gave me some kind of intravenous medication that stopped the attack. I've since learned that those were symptoms of a lidocaine overdose, which could have progressed to seizures or coma.
Buffering Lidocaine
Injectable lidocaine is quite acidic and for some its very painful when injected before it takes effect (like injecting lemon juice). However it can be buffered with sodium bicarbonate to reduce the acidity and hence pain, and in my experience this eliminates the majority of pain associated with these injections. You still have the needle pain, but not the intense pain of the lidocaine; its very different. Although its easy to buffer lidocaine, most doctors won't bother - its a waste of time and its not like they feel anything. Most patients don't know about this either, so no problem.
I've had buffered lidocaine and it works very well. While I've not experienced it myself it appears to be possible to totally eliminate all pain with buffering, very fine needles, and different injection techniques - but that probably really is a waste of time unless you have some issue with it.
Lidocaine is not manufactured pre-buffered as it reduces the shelf life. However once mixed it can be stored for a reasonable length of time, weeks to months under suitable conditions according to the referenced papers.
YouTube
Papers
- 2019 - Do buffered local anesthetics provide more successful anesthesia than nonbuffered solutions in patients with pulpally involved teeth requiring dental therapy?: A systematic review by Sereen Kattan, Su-Min Lee, Elliot V Hersh, Bekir Karabucak (full copy here)
- 2018 - Finer Needles Reduce Pain Associated With Injection of Local Anesthetic Using a Minimal Insertion Injection Technique. by Zelickson BR, Goldberg LH, Rubenzik MK, Wu WJ.
- 2017 - Parallel, minimal needle-insertion technique for achieving a painless injection of local anesthetic. by Zelickson BR, Goldberg LH, Rubenzik MK, Wu WJ, Sinai M.
- 2017 - Do Buffered Local Anesthetics Provide More Successful
Anesthesia Over Non-Buffered Solutions in Patients RequiringAnesthesia Over Non-Buffered Solutions in Patients Requiring
Dental Therapy? – A Systematic Review & Meta-Analysis.Dental Therapy? – A Systematic Review & Meta-Analysis - Masters Theseis by Sereen Kattan at the University of Pennsylvania, Committee members Bekir Karabucak, Elliot V. Hersh, Johnathan M. Korostoff, Paul Hunter
- 2013 - Minimizing the pain of local anesthesia injection. by Strazar AR, Leynes PG, Lalonde DH.
- 2012- How acidic is the lidocaine we are injecting, and how much bicarbonate should we add? by Simon G Frank, and Donald H Lalonde - "The epinephrine-containing solutions were more acidic than their plain counterparts by an absolute magnitude of 1.85 for 1% lidocaine and 2.07 for 2% lidocaine (P<0.05). There was no significant difference in the pH between the 1% and 2% solutions."
- 2011 - Alkalinisation of local anaesthetic solutions - "Commercially available acidic local anaesthetic solutions have a pH of typically 3.5 to 5.5 and have a shelf-life of three to four years. ... Hydrochloric acid is added to lignocaine solutions to achieve this low pH. "
- 2011 - Stability of Buffered Lidocaine in Glass Vials by Ronald F Donnelly - "On the basis of the information presented here, solutions of 1% buffered lidocaine packaged in glass vials may be stored at 23°C with exposure to light or at 5°C with protection from light for up to 91 days."
- 2009 - Buffered Lidocaine Hydrochloride Solution With and Without Epinephrine: Stability in Polypropylene Syringes
- 1998 - Pain reduction in local anesthetic administration through pH buffering by R A Christoph, L Buchanan, K Begalla, S Schwartz
Safe Dosage of Sodium Bicarbonate
I can't find proper information on this, so I'll make a guess based on how its used to tread medical problems. In this document, SODIUM BICARBONATE- sodium bicarbonate injection, solution General Injectables & Vaccines, Inc it says that for 8.4% Sodium Bicarbonate solution the is 1 mEq/mL, and "The amount of bicarbonate to be given to older children and adults over a four-to eight- hour period is approximately 2 to 5 mEq/kg of body weight — depending upon the severity of the acidosis as judged by the lowering of total CO2 content, blood pH and clinical condition of the patient". I'll assume that this treament dose is "safe" (probably a really bad idea).
For a body weight of weight of 100kg, 2 mEq/Kg is a dosage of 200 mEq, or 200ml of 8.4% solution. Given that 100ml of injected saline would contain around 12 ml of lidocaine, and 1.2ml of 8.4% sodium bicarbonate, there's around 100 times margin. This is also ignoring the reaction between the acidic lidocaine and sodium bicarbonate which I assume forms salt (NaCl), further increasing the margin. Adjusting the ratio of sodium bicarbonate to lidocaine (from 1:10 to 1:3 ) in this solution won't make much difference.
Lidocaine Allergy
Some people are allergic to lidocaine and/or other anesthetics, and it can be very dangerous if not treated (probably why only midical practitioners are licensed to use it - they are trained to save you)
reddit
Papers
- 2020 - Articaine as an alternative in lidocaine allergy: Case report of a seventy year old male patient
- 2019 - Anaphylactic reaction after local lidocaine infiltration for retraction of retained teeth - "Lidocaine is a very popular drug in dental procedures and anaphylactoid reaction to it has been rarely reported. Clinicians who use lidocaine daily should, however, be aware of the possibility of anaphylaxis after its use. Once it occurs, anaphylaxis can be fatal..."
- 2018 - True Allergy to Amide Local Anesthetics: A Review and Case Presentation
- 2016 - Lidocaine Allergy: Do Positive Patch Results Restrict Future Use?
- 2014 - Allergy to lidocaine injections: comparison of patient history with skin testing in five patients
- 2009 - Clinical examination of challenge test to local anesthetics by Takefumi Yamaguchi, Kazuyuki Nakagome, Kiyoshi Udagawa, Yotaro Takaku, Nagato Sato, Tomoyuki Soma, Kouichi Hagiwara, Minoru Kanazawa, Makoto Nagata - " Although adverse reactions to local anesthetics are often diagnosed as local anesthetic allergy, there is evidence that most of these reactions occur via non-allergic mechanisms."
- 2012 - Anaphylactic shock following administration of lidocaine after negative skin test - "A rare case of sudden fatal anaphylactic shock is described in a 50 year-old woman after secondary lidocaine blockade to relieve lumbar pain... The diagnosis was confirmed at autopsy;"
- 2003 - Delayed-Type Hypersensitivity to Lidocaine
Lidocaine Resistance
Some people are resistant to lidocaine injections. This is/may be correlated with red hair and Ehlers-Danlos Syndrome (EDS).
BBC
RDH Magazine
Papers
- 2022 - Resistance to local anaesthetics: a literature review by Florian Marti, Gregor Lindner, Svenja Ravioli - I've not read this one yet
- 2019 - Resistance to local anesthesia in people with the Ehlers-Danlos Syndromes presenting for dental surgery by Jane R Schubart, Eric Schaefer, Piotr Janicki, Sanjib D Adhikary, Amber Schilling, Alan J Hakim, Rebecca Bascom, Clair A Francomano, Satish R Raj - " EDS survey respondents reported nearly three times the rate of LA non-response compared to non-EDS respondents... The agent with the highest EDS-respondent reported success rate was articaine (30%), followed by bupivacaine (25%), and mepivacaine (22%)."
- 2013 - Response to “Does scorpion bite lead to resistance to the effect of local anaesthetics?” by Trescot, Andrea
- 2005 - Local anaesthetic failure in joint hypermobility syndrome by Alan J Hakim, Rodney Grahame, Paul Norris, and Colin Hopper - "When taking biopsies to assess skin strength in Ehlers–Danlos syndrome type III (EDS–III), a Danish group noticed that the patients experienced much pain despite conventional local anaesthesia."
- Increased sensitivity to thermal pain and reduced subcutaneous lidocaine efficacy in redheads by
Edwin B Liem, Teresa V Joiner, Kentaro Tsueda, Daniel I Sessler - "Red hair is the phenotype for mutations of the melanocortin-1 receptor. Results indicate that redheads are more sensitive to thermal pain and are resistant to the analgesic effects of subcutaneous lidocaine."
- 2003 - Local anesthetic "resistance" by Andrea M Trescot - "Although most were equally numb to all three local anesthetics (lidocaine, bupivicaine, and mepivicaine), 7.5% of the patients consistently chose mepivicaine as the local anesthetic resulting in the most hypoesthesia. For patients who had previously undergone an unsuccessful procedure with bupivicaine (the standard local anesthetic used in our practice), the same procedure with mepivicaine provided good relief." - PDF here.
Lidocaine vs Lignocaine
These are the same drug. Lignocaine is the old name for the drug in some countries, while Lidocaine is the
International nonproprietary name (INN). Renaming has been taking place in some countries as part of standardisation.
- 2020 - Updating medicine ingredient names - "In different countries, different names are used to describe the same medicinal ingredient. Over the years, some medicine ingredient names in Australia became out of date. This can be confusing for Australian consumers and healthcare professionals who travel internationally, as well as people like doctors who have trained overseas or people trying to access medicine information online. We have updated some medicine ingredient names used in Australia to align with names used internationally. This has been done by some other countries over the years, including the United Kingdom in 2003 and New Zealand in 2008."
- 2003 - Name Changes of Medicines in UK - "For many years the UK had its own naming system. Each medicine had a British Approved Name (BAN). However, European law says that medicines should be called the same in all EEC countries. So, the name of each medicine is now the recommended International Non-proprietary Name (rINN). As medicines are now named the same all over Europe, it should reduce the risk of medication errors."
Bupivacaine
Also known as Marcaine.
The key difference between bupuvicaine is its very long duration of action (2-8 hours) compared to lidocaine (0.5-3 hours). In principal this would be an advantage if you were only able to get a single set of injections before electrolysis, however I'm not yet aware of anyone using this for electrolysis.
According to this pdf Bupivacaine is buffered at 0.1ml 8.4% sodium bicarbonate to to 20ml 0.25%-0.5% bupuvicaine, and it must be measured carefully to avoid precipitation.
Papers
- Buffered lidocaine 1%/epinephrine 1:100,000 with sodium bicarbonate (sodium hydrogen carbonate) in a 3:1 ratio is less painful than a 9:1 ratio: A double-blind, randomized, placebo-controlled, crossover trial by Alexandra Vent, Christian Surber, Nicole Tracy Graf Johansen, Verena Figueiredo, Georg Schönbächler, Laurence Imhof, Caroline Buset, Jürg Hafner
I need to investiate the max dose and possibility of dilution. Also I think I read that bupvicaine cannot be injected painlessly as it doesn't number as its injected in the way lidocaine does - but it can be mixed to lidocaine to achieve this.
Ropivacaine
Possibly longer duration than Bupivacaine.
https://en.wikipedia.org/wiki/Ropivacaine
Papers
Prilocaine
https://en.wikipedia.org/wiki/Prilocaine - "Prilocaine is a local anesthetic of the amino amide type first prepared by Claes Tegner and Nils Löfgren. In its injectable form (trade name Citanest), it is often used in dentistry. It is also often combined with lidocaine as a topical preparation for dermal anesthesia (lidocaine/prilocaine or EMLA), for treatment of conditions like paresthesia. As it has low cardiac toxicity, it is commonly used for intravenous regional anaesthesia (IVRA)."
Papers
EMLA
Prilocaine is combined with Lidocaine as EMLA. According to the 2012 paper below, this is because the eutectic mixture has enhanced absorption (of lidocaine) compared to using only lidocaine individually (its still a very weak topical anesthetic though).
https://www.pccarx.com/Blog/2-tips-for-compounding-with-lidocaine-and-lidocaine-hcl - "Some drug powders, when mixed together in a dry state, lower each other’s melting points to below room temperature, causing them to melt (liquify). This is called a eutectic mixture, and it occurs with chemicals like camphor, menthol, phenol, chloral hydrate, hydroquinone and aspirin as well as benzocaine, lidocaine and tetracaine... Combining anesthetics such as lidocaine, benzocaine and tetracaine or lidocaine and prilocaine is common practice in the compounding pharmacy, mainly so that practitioners can anesthetize the skin prior to needle sticks or for laser hair reduction and other dermatological procedures. When higher concentrations of these active pharmaceutical ingredients (APIs) are required, forming a eutectic mixture initially may help to keep the preparation from crystallizing over time in some cases... For topical creams, forming a eutectic mixture may be desirable because it eliminates the need to levigate (wet) the powders since there is no longer any surface air to displace. A drug in a liquid state should show superior absorption compared to a solid drug powder as well... You can create a eutectic mixture by triturating these APIs together in a mortar and pestle. This can only be achieved using the “free base” forms, not the hydrochloride salt forms. This process takes a few minutes to achieve and requires some physical force. For example, a typical 100 Gm BLT (benzocaine, lidocaine and tetracaine) formula may require vigorously triturating for 5-7 minutes, depending on the concentrations. The mixture will first become sticky and then will become a viscous liquid... Certain bases should not be used with the salt forms of the “‘caines,” such as lidocaine, tetracaine and benzocaine. For example, VersaBase® Gel (PCCA #30-3656) can only hold approximately 2% maximum salt (HCl) load, and Plasticized™ Base (PCCA #30-3211) has a low salt-load capacity as well. PCCA formulas provide guidance on which PCCA bases will hold certain combinations and concentrations of anesthetics."
- https://en.wikipedia.org/wiki/Lidocaine/prilocaine - "Separately, lidocaine and prilocaine are solid bases. When mixed in equal quantities by weight, however, they form a eutectic mixture – that is the melting point of the mixture is lower than the melting points of the individual components. The lidocaine/prilocaine eutectic mixture is an oil with a melting point of 18 °C, and can be formulated into preparations without the use of a non-aqueous solvent. This allows higher concentrations of anaesthetic to be formulated into the preparation and maintained during application."
- 2012 - Comparison of Five Commonly-Available, Lidocaine-Containing Topical Anesthetics and Their Effect on Serum Levels of Lidocaine and Its Metabolite Monoethylglycinexylidide (MEGX) by Georgette Oni, Spencer Brown, Jeffrey Kenkel - "What was interesting to note is that the 2.5% lidocaine-containing formula had the greatest absorption when compared with the 4% and 6% lidocaine-containing products. This is because the drug exists in a eutectic mixture with 2.5% prilocaine. The significance of this is that the active ingredients (ie, lidocaine and prilocaine) exist as an oil-in-water mixture with a lower melting point of 18°C. This means that at room temperature, lidocaine and prilocaine exist as a liquid rather than a solid, and absorption is therefore enhanced."
Field/Nerve Blocks
https://en.wikipedia.org/wiki/Nerve_block
- 2014 - Infiltrative Anesthesia in Office Practice by JOSHUA L. LATHAM, SEAN N. MARTIN - "Local cutaneous infiltration is the most commonly used anesthetic technique and involves direct injection into the area requiring anesthesia. Field blocks provide anesthesia by circumferentially blocking innervation to the area. Nerve blocks target the innervation to a specific area and are useful on the face and digits."
- 2008 - Pathophysiology of Peripheral Nerve Injury During Regional Anesthesia by Quinn H. Hogan - "Although the great majority of peripheral nerve block anesthetics are followed by complete return to normal nerve activity, a small number result in persisting deficits of motor or sensory performance, or in the generation of pain."
reddit
- reply to How to buy medical supplies - "Local anesthetics are used for nerve blocks by people who know what they’re doing. You never inject into the nerve you’re trying to block, but rather in the general area such that the anesthetic spreads locally through the subcutaneous tissues to bathe the target nerve. As you said, much like injecting an epidural anesthetic directly into the spinal cord, injecting anesthetic into a peripheral nerve will cause permanent damage to the affected nerve. Source: Neurology resident who has performed a number of peripheral nerve blocks and gotten many talks from pain specialists about the ramifications of fucking up"
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