When one thinks of local anaesthesia, one tends to think of cocaine and its numerous synthetic analogues.  Given that the necessary means of manufacture, delivery and effects monitoring of this type of anaesthetic are heavily dependent on modern advanced technology and scientific knowledge, it is no wonder that the history of local anaesthesia in that sense is very short.  In fact, its first recorded appearance as a separate concept is due to Sir James Young Simpson (1848) in a review of alternatives to ether anaesthesia.[1]

Although the involvement of the brain and spinal cord in sensation and movement was recognised as early as the Ancient Egyptians, they had no concept of the nervous system as such or the process of nerve conduction; nobody did, at least in the West,  until it was first investigated by Galen (129-216), who described a network of nerves leading to the brain, and recognised that "Nature....wished to give....the faculty of recognising an injury.....the perception of that which can cause harm." (De Usu Partum).  He also carried out experiments on pig spinal cords to illustrate which areas deprived of sensation when certain parts of the cord were cut. (De Locis Affectis)  But even then, the belief was that nerve transmission was via liquids (“animal spirits”) physically flowing through the nerves, which acted only as conduits.

It was Descartes (1596-1650) who first stated that pain was experienced in the brain, rather than in the heart as was the accepted Aristotelian doctrine, although he still believed in animal spirits, and conceived nerve transmission to be purely mechanical.

Indeed I have seen it claimed, that the history not only of anaesthesia but pain relief in general, does not begin until the rise of humanitarianism, because “History teaches us that man has usually been tolerant of pain, especially in others....it was not until the second half of the eighteenth century of the Christian era that a new feeling spread abroad.”[2]

With the greatest respect, I suggest that this is a load of b*ll*cks.  In the absence of any effective means of diagnosis of illnesses, let alone treatments or cures, medical history, folk and official, is emphatically that of searches for pain relief, both general and local.  And I shall show that considerable ingenuity was applied to this search.  Moreover the Christian Church’s influence (often blamed for inculcating an acceptance of pain) on the everyday consciousness and practices of your average Joe is more asserted than proved, besides being restricted to relatively few centuries and peoples.  The opium poppy was cultivated in Mesopotamia over 5,000 years ago and has been in continuous cultivation, somewhere, ever since; the Sumerians called it Hul Gil, which has been translated as joy plant, suggesting at least a recreational use[3]; in the earliest medical texts opium is found, and was used in Egypt (evidenced by medical papyri and inscriptions) before 1500 BCE and on Crete and the Greek mainland  by 1300 BCE.[4] Henbane (Hyoscyamus niger) analgesia goes back to 2500 BCE[5], alcohol was recommended by the Hindu surgeon Susruta about 1000 BCE.[6] Similar antiquity can be traced for other anodyne herbals such as cannabis, hemlock, coca and mandrake.

Nor is it any explanation to generalise that all surgeons (anaesthetists as a separate discipline didn’t really exist until the end of the nineteenth century) were themselves indifferent to pain, because many have left records to show that they weren’t; although it is not entirely fair to condemn a modern judgement that they actually “deliberately chose to” inflict it[7]

as “vacuous”[8] because unfortunately some did, albeit for non-sadistic reasons: “however barbarous it may appear, the smart of the knife is a powerful stimulant; and it is much better to hear a man bawl lustily than to see him sink silently into the grave.”[9]

Let's get a few definitions out of the way, okay?  Anaesthesia is the absence of sensation.  Analgesia is the absence of pain.  Pain is any localisable noxious sensation.  (Yes, yes, I know that would include tickling and nasty smells, but let it go, please.)

I shall have to consider local analgesia also, because for most of recorded history the two were regarded by most medical authorities as identical. (One conspicuous exception is the Arabian physician Avicenna (980-1037), who made an explicit distinction as early as the tenth century.)[10] Like so many matters in the history of pain relief, this distinction was lost and only rediscovered as medicine became scientific in the nineteenth century.

Moreover, the history of surgery is presumably at least as ancient as the Palaeolithic bonesetter who patched up the members of his tribe after an encounter with another tribe, or with an unco-operative beast of prey or food animal.  The earliest surgery may have been trepanning [drilling holes in the skull, theorised to be originally for letting out demons]; even the Neanderthals indulged in it. So what methods of pain relief/abolition, if any, were obtainable before, say, the nineteenth century?

We can divide practice into two approaches:  mechanical and chemical.  The mechanical involves physically interfering with the local nerve conduction process, by compression, cooling, warming, counter-irritant, venesection or nerve section.  Such methods have been available to any practitioner, however basic.

Chemical methods I take to be the application of anodyne/anaesthetic/counter-irritant substances to the specific area, by injection into the nerve or adjacent tissue, or topically via mucous membrane, transdermal, or eye surface absorption.

Partaking of both, is the process of nerve destruction by chemical injection, such as phenol.

I suspected acupuncture and acupressure ought to fit into this somewhere, but apparently the action, as far as it has been investigated, is central rather than local[11].

Nerve compression is achieved by tourniquet or by manual pressure.  It works by compression of the blood vessels, denying oxygen to the tissues below the tourniquet.  The method was probably discovered when the first ligatures were applied to stem haemorrhage, but seems to have been repeatedly forgotten by medical practitioners, if not by their victims, sorry, patients. It has been claimed that a wall-carving at Saqqara (2,500 BCE) illustrates its use[12], although on personal viewing this is doubtful as the attendants could be doing almost anything to the patient.† Apparently the Romans used ligatures, though whether this was for anaesthesia or haemostasis I have been unable to establish.  The method does not then re-emerge (at least in the West) until the sixteenth and seventeenth centuries, among surgeons dealing with amputations.  (These were much commoner before antibiotics, because the only sure way to prevent death from septicaemia once any lesion had become infected, was to amputate.)   In 1564 the military surgeon Ambroise Paré (1510-91) noted that a tourniquet “much dulls the sense of the part by stupefying it: the animal spirits by the straite compression being hindred from passing in by the nerves”[13]; similarly William Clowes, naval surgeon (1544-1604), advocated “a straight band, or ligature, which band indeed is also very necessarie, for, by reason of the hard and close binding,  it both so benum that part, that the paine of the binding doth greatly obscure the sence, and feeling of the incisson.”[14]

In contrast, another naval surgeon John Woodall (1556-1643), although acutely conscious of the agony caused by amputation, and a fervent advocate of laudanum (tincture of opium) as an analgesic, betrays not the slightest knowledge of compression or ligatures, except as a way of controlling haemorrhage:  “the party that holdeth the vpper part of the legge with all his strength, gripping the member together to keepe in the spirits & bloud.”[15]

In 1784 an attempt was made to introduce compression into hospital surgical practice. The great surgeon John Hunter agreed to use a device invented by a young doctor, James Carrick Moore (1763-1834), during a below-knee amputation; although the procedure was successful, at least anaesthetically (I do not know whether the patient survived the inevitable post-operative infection), in that the patient reported little discomfort, neither Hunter nor Moore nor anyone else appears to have followed this up at all; for example, in 1788 the surgeon Benjamin Bell was recording that “in amputating limbs, patients frequently desire the tourniquet to be tightly screwed, from finding that it tends to diminish the pain,” but does not reveal any knowledge of the Hunter-Moore experiment.[16]

But, as every First-Aider knows, compression can be a dodgy business, because too prolonged tissue anoxia leads to irreversible damage.  When I was involved with St John Ambulance in the 1980s, the advice given was that one could be sued for this, and the defence to be successful would have to prove that the subject would have died from blood loss otherwise.

Compression analgesia, I thought, would have no place in modern anaesthetic practice, but it survives in odd little corners. For example, the removal of velvet antlers from deer.   This usage is somewhat controversial; the Alberta Reindeer Association, for example, claims that it is analgesic as well as preserving haemostasis[17], whereas research by other veterinarians concludes that “compression of the antler pedicle appears to be noxious” and thus not to be recommended.[18] Compression has also been tried for the relief of migraine headache, accompanied by heat and/or refrigeration therapy,[19] but its precise mode of action I don’t know.

Cooling (refrigeration anaesthesia), even if not always to zero or sub-zero temperatures, has been employed since early times.  Hippocrates (b. c.460 BCE)  stated that “swellings and pains in the joints, without ulcerations, those of a gouty nature, and sprains are generally improved by a copious infusion of cold water....for a moderate degree of numbness removes pain.”[20] Avicenna[21] used sips of ice-cold water to numb a tooth and gum before surgery. In the Old English Lacnunga (c.1000) there is a recipe: to treat an abscess, let him sit in cold water till it be numb, (“wið omena gebærste, sitte on celadum wætere, oððæt hit adeadad sy,”[22]) before attempting to lance it.  Johannes Costaeus (De ignis medicinae praesidiis, 1595) mentions the use of snow and ice for surgical anaesthesia, and the Italian Marco Aurelio Severino (1580-1656) and the Dane Thomas Bartholin (1616-80) used it for perineal lithotomy in the seventeenth century (but Samuel Pepys was offered no analgesia at all). Again, Dominique Baron Larrey (1766-1842) surgeon in Napoleon's Army, used snow to facilitate the amputations resulting from battle wounds; he had observed that the cooling process had the advantage, like compression, of also reducing haemorrhage.

The main advocate was a nineteenth century British surgeon, James Arnott; he was concerned by the fatalities associated with the early days of ether and chloroform anaesthesia, admittedly then a very hit-and-miss procedure, and he repeatedly promoted refrigeration as much safer.  “In all superficial operations, which constitute the immense majority, cold is superior to chloroform in the circumstances of safety, ease of application or the saving of time and trouble, certainly of producing anaesthesia, and lastly, in the power it possesses of preventing subsequent inflammation.”[23] His method involved a mixture of crushed ice and salt, applied via a clear glass tube to the skin where the operation was to take place.[24]

Refrigeration must have continued as a half-recognised source of anaesthesia within the military context for many years, in the absence of anything better.  In 1854 during a controversy about the safety of use of chloroform for battle wounds (the dangers of shock and of chloroform-induced ventricular fibrillation were just becoming recognised), “A Military Surgeon” wrote to The Times that “it is cheering to know that, at several of the London Hospitals, the perfectly safe practice (already extensively adopted in France) of benumbing the part with cold, previously to its incision, is now being substituted for chloroform in a large class of operations.”[25]

Nevertheless, refrigeration suffers the same disadvantage as compression: potential damage due to tissue anoxia. And also difficulty of application where internal procedures are necessary. Arnott himself admits these drawbacks.[26]

The development of safer general and more effective local anaesthetics meant that his method failed to gain general acceptance, but refrigeration anaesthesia has never quite gone away.  It developed into cryosurgery and cold hydrotherapy[27] but also crops up as a possible alternative to conventional anaesthesia, in favourable circumstances, during the twentieth century.  In 1946 an American dentist, harking back to Avicenna, described a quite horrendously uncomfortable-looking apparatus for delivering refrigeration anaesthesia to the jaws of naval personnel (who presumably were not in a position to say No, they’d rather have Novocaine, thank you),[28]and in 1971 a plastic surgeon recorded its use when harvesting skin for autologous grafting, the advantage here being that the patients, already shocked by burns or other trauma, were not subjected as well to the stress of  general anaesthesia.[29]

The nineteenth century saw the use of  cooling by evaporation of volatile liquids: in 1859 Richet used ether evaporation from the skin to produce local anaesthesia. Ethyl chloride, when applied to the skin as a spray, causes a transient sensation of extreme cold and gives adequate anaesthesia for minor, rapid procedures.  In 1848 Heyfelder had used ethyl chloride in Germany as a general anaesthetic; its local action was discovered quite by chance later.  Unfortunately, like ether,  it is also extremely flammable, and after a number of disastrous fires, fell out of favour except in very limited circumstances, for example, when performing intravenous cannulation. Benzyl alcohol has been used for topical anaesthesia of mucous membranes and to control cutaneous itching; saligenin (salicylic alcohol) a colourless crystalline solid soluble in water 1:15, has been used for injection anaesthesia of the urethra for cystoscopy.  From the nineteenth century on, liquefied or solidified gases –  O₂ , N, CO₂ and many more, have continued to be used in cryotherapy.[30]

Cold analgesia has been used successfully in the treatment of migraine since the tenth century at least; Avicenna reported successfully treating his own hemicranial headache with crushed ice held in place by a cloth.[31] The technique was still being evaluated (using cold gel packs) in 2006.[32]

Refrigeration analgesia continues to be used, for RSI and sports injuries especially: the simplest form being the cold water compress, and more effectively the gel pack which is stored in a freezer until used.  (Although a chiropractor I once consulted advocated the use of packs of frozen peas, as being more effectively moulded to the human shape.)  And I gather that it still finds favour amongst adolescents intent on acquiring body-piercings by their own efforts, using ice-cubes.

In contrast, the local application of heat is analgesic (sometimes) but not, alas, anaesthetic; nevertheless it deserves a mention.  It works by dilating superficial capillaries thus increasing blood flow, and helps relax muscles and reduce inflammation and thus pressure.  Celsus (25 BCE-50 CE) remarks that toothache “can be counted among the greatest of torments” and recommends among other remedies, steam from hot water “to be applied by a sponge.....with a woollen bandage over it, and the head must be wrapped up......a hot poultice upon the cheeks, and hot water containing certain medicaments held in the mouth and frequently changed.” (Liber VI, ix)  Later, a fifteenth-century recipe urges the sufferer to “Take the root of quincfoyle & seth it wele in vinakyr or in wyne & hold it somdelle hote as he may suffre hitt a gude while in his mouth & it shall do away the ach.”[33]

Poulticing is a very old method of applying heat analgesia, plus the option of topical administration of transdermal drugs, and was still in use when I was a nursing student in the 1970s.  It consists of a heat-retaining inactive matrix (kaolin is the one most used in modern poultices, whereas cooked and mashed grain appears in older recipes) possibly combined with pharmaceuticals.  Older recipes are more adventurous: “Take hundisburies of the hegge & stamp heme & take Þe juse by it selue and the croppys of nettilis with the seed dried and small powd^r and colvere dunge powdred & pporcione euen the jusis & put þ^rinof thies powdres so þat it be nat to thikke and fry hem all in may buttur or in swynys grese and so hote enoynt the place that alyth agayne the fyre and do this oft and bynd the substance to the sore place and kepe the jusis and þ^e powders ech by them selue till þ^w will vse hem pb est.”  (deadly nightshade berries, nettles, pigeon droppings [presumably the matrix], butter or pork fat [presumably to ensure adhesion].  Probatum est??)

In the seventeenth century Woodall recommends “good fomentations” and good warme medicines duely applied” in the treatment of Apostumes (abscesses, boils etc).[34] Today’s physiotherapists use packs of heat-retaining gel, whereas more ecologically-minded souls prefer scented wheat in pretty cotton covers.

Piles [haemorrhoids] are by no means a product of modern stressful, over-sedentary life.  The Lacnunga has a recipe which, somewhat modified, is still used by seekers after relief today:  steam:  “læt niman ænne greatne cwurnstan & hætan hine & lecgan hine under þone man, & niman wælwyrt & leomucan & mucgwyrt & lecgan uppan þone stan & on under, & do þærto ceald wæter, & læt reocan þone bræð upon þone man, swa hat swa he hatust forberan mæge.”[35] (crouch over a large heated quernstone, on which wallwort, brooklime and mugwort are lying, and wet it so that it steams.)  The anodyne effect would derive from the steam, not the plants.

Counter-irritant, in its simplest form, is a mother comforting a bruised child with “Let’s rub it better.”  The principle is to overload the sensory input with non- or less- or different noxious stimulation, so that the pain messages are blocked.  The Chinese pioneered moxibustion, or more crudely, blistering:  placing something inflammable on the painful area and setting light to it. The ancient Western practices of blistering and cupping must similarly have worked (if they worked at all) as counter-irritants, although the underlying theory is quite different:  Western doctors believed that the blistering induced the malign humours causing the pain to escape.[36]

The eighteenth century saw great interest in the newly-discovered powers of electricity.  The application of electric shocks in the cause of local analgesia became very popular, if poorly understood, and quackery abounded (as it still does). In one of the first ever recorded clinical trials, a practitioner named Elisha Perkins who claimed to cure just about anything by means of “tractors” – metal conducting rods applied to the painful area – was exposed by one Dr John Haygarth, who set up a sting in which a placebo -  wooden rods mocked up to resemble metal – were used on one group of patients, metal on another, and the results compared:  guess what they revealed?[37]

Nevertheless electrical stimulation continued to be used as an adjunct to topical anaesthesia with cocaine, in order to potentiate the effect of the latter,[38] but largely fell out of favour as the technique of hypodermic injection became possible.

The modern ethical Western descendant is TNS, transcutaneous nerve stimulation, a type of electro-anaesthesia, in which a low voltage electrical current is applied intermittently to a nerve, causing reverse flow or blockage of impulses.  It is widely used, both in minor surgical procedures such as dentistry, and in the treatment of chronic pain, such as lumbago.

Nerve section properly belongs to the age of heroic surgery, or more correctly heroic patients.  The nerve is surgically cut and a portion destroyed, and that’s it.  Irreversible damage is the result, in the case of the spinal cord.  The observation that damaged or destroyed nerves resulted in loss of sensation or in paraesthesiae was known to the Ancient Egyptians, though whether they proceeded to apply the knowledge in the cause of pain relief I don’t know.  As late as the 1930s, it was suggested that Sir Edward Elgar, suffering the agonies of terminal bowel cancer, should have his spinal cord surgically resected in order to afford him anaesthesia with full mental alertness (so that he could complete his last work); Elgar died before the procedure was more than a gleam in a surgeon’s eye.

Moreover, nerve destruction, whether by scalpel or by chemical, tends to have an unpredictable and intractable outcome.  Many an amputee can tell you about phantom limb pain.

Venesection was certainly used as an analgesic procedure, possibly as late as the nineteenth century, quite reasonably according to the theory that the pain was caused by acrimonious humours which needed drawing off.[39] It is not recommended.

In the absence of any understanding of the nervous system, our ancestors assumed that substances which were analgesic on ingestion or inhalation, would be just as effective transdermally.  To an extent they were right, in that some substances can be so absorbed, and once absorbed can work centrally:  nicotine (from tobacco spray and patches) is a good example.[40] Today paracetamol patches have been tried (with limited success) in the treatment of arthritic pain. But the number of drugs that can also have a specific local action is, however, probably much smaller than ancient recipes would imply, although it is wise to be cautious about dismissing such claims without clinical investigation.  Galen, for example, recommended opium paste as a local application for toothache; the effectiveness of this would depend upon the type of pain.  Morphine, once thought to be purely a centrally-acting analgesic, has indeed been shown to have some kind of local effect in chronic dental pain, but not in acute inflammatory pain.[41]

Folk pharmacopoeias are full of herbals whose anodyne/anaesthetic effect is counter-irritant, including many rubifacients such as St John’s Wort (Hypericum perforatum), many of which have been investigated in the hope of providing alternatives.  The most

widely used today is probably capsaicin, C₁₈H₂₈O₃N, derived from chilli peppers (Capsicum).  The active compound is 8-methyl-N-vanillyl-6-nonenamide, which is extremely irritating to the skin, eyes and mucous membranes of mammals, as anyone who has rubbed their eyes after chopping a pepper can testify.  It is also an ingredient in “pepper spray” for riot control, and in theory could be fatal in overdose.

Capsaicin works by excitation of the sensory neurones, which initially produces the “burning” sensation, but with prolonged exposure, say by the application of an ointment, the neurones are depleted of their neurotransmitters and hence there is a reduction in the sensation of pain and eventually numbness; this is a reversible effect simply by removing the capsaicin, although prolonged exposure does lead to cell death.  Originally it was hoped that it would be of use in treating intractable neuropathic pain, such as that caused by post-herpetic [shingles] inflammation; that has not been entirely successful; it is now also found in a number of creams for minor sports injuries, mouthwashes for ulcers, and the like.[42]

In Europe, the classic counter-irritant has always been the stinging-nettle, Urtica spp, with a long history in folk medicine.  The antiquary Camden (1551-1623) claims that “the [Roman] soldiers brought some of the nettle seed with them, and sowed it there for their use to rub and chafe their limbs, when through extreme cold they should be stiff or benumbed”.[43] From it derives the term urtication, meaning flogging with nettles in the cause of pain relief.  Nettle sting contains histamine, oxalic acid, tartaric acid, and in lesser quantities formic acid (same as in ant stings) and serotonin[44], and they are also claimed to curdle milk, render leaky wooden vessels waterproof, and “if planted in the neighbourhood of beehives, it is said the Nettle will drive away frogs,”[45], a fairly esoteric use one would have thought.† Exactly which component causes the characteristic pain has not yet been established. The plant has been investigated clinically for efficacy as a local analgesic in the treatment of osteoarthritic pain and has been found to be significantly more effective than placebo,[46] and is also used in the treatment in various allergic, autoimmune disorders and in benign prostatic hyperplasia.

(Incidentally, the nettle in the poultice recipe above would have been useless as a counter-irritant, if that is what it was for (it has no analgesic properties otherwise), because nettle sting is inactivated once the plant has wilted.)

The best-known topical anaesthetic probably is or are Cloves (Syzygium aromaticum syn. Eugenia aromatica) which are native to the Spice Islands (Banda Islands) and grow nowadays also in Madagascar, Zanzibar, India and Sri Lanka.  They have been known and valued as a condiment throughout Europe and Asia for a couple of millennia at least.

They contain an essential oil, of which eugenol, or eugenic acid, C₁₀H₁₂O₂, is the main constituent and which has both antiseptic and potent dental anaesthetic properties.  The knowledge of this as a potential source of local anaesthetic predates that of cocaine, in the West, by centuries.  In the seventeenth century Woodall recommends Oleum Garyophillorum (Oyle of Cloues) as it “asswageth the paine of the teeth proceeding from a cold cause,”[47] and then as now it was used to relieve toothache by the time-honoured method of dabbing some on a small piece of absorbent substance which was then inserted into the cavity and left in situ.  Its mode of action is not well understood but studies have shown that it is a powerful anti-inflammatory.

The genus Piper is widespread across South America, Africa and Asia and various species have been used to relieve minor pains, especially toothache and sore throat, by local application.  The active ingredient is piperovatine, an isobutyl amide which is also widely used as a piscicide in South America. Research suggests that it has voltage-gated sodium-channel agonist properties.[48]^,[49] The Chinese preferred Long pepper (Piper longum) which as been used both as a centrally-acting analgesic since the Tang Dynasty, and made into pills with wax and rubbed onto aching teeth.[50]

The Arabs, during our Dark Ages, developed a large pharmacopoeia for pain relief both local and central.  Opium, mandrake, and henbane were all used topically in dentistry, and also, with nightshade (Solanum spp) to treat ear and eye pain, in the various forms as suitable, of gargles, drops, pastes, dressings or patches.[51]

Henbane (Hyoscymaus spp) contains tropane alkaloids, principally hyoscyamine and hyoscine (scopolamine), which have a central sedative action, but apparently it also has a mildly benumbing action on the buccal mucosa. For toothache, Celsus recommends a decoction of the root held in the mouth but not, he cautions, swallowed, (Liber VI, ix) and for the same reason, from very early times the roots, dried, were made into anodyne necklaces/ rattles for babies for teething:  “To Make Children’s Necklaces for the Teeth.  Take roots of hen bane, of orpin and vervain, and scrape them clean with a sharp knife, cut them in long beads and string them green.....till it is the bigness of the child’s neck.  Then take as much red wine as you think the necklace will take up and put thereto a dram of red coral, and as much single peony root, finely powdered.  Soak the beads in this for 28 hours, and rub the powder on the beads, and when red and dry, let the child use them.”[52] Don’t try this at home.

Henbane was also an earache remedy, according to the Old English Herbarium: “Wið earena sár genim Þysse ylcan wyrte seaw & wyrm hit, drype on Þæt eare, hyt wundorlicum gemete Þæra earena sár afligð,” the juice of henbane warmed and dripped into a sore ear is a marvellous remedy.[53]

Just out of curiosity I tallied a few of the topical anodynes listed in my fifteenth-century leechbook[54]:  cinquefoil root, hartshorn, tansy, onion, pepper, figs, cumin, raven’s dung, pellitory, ivy-berries, wild celery, henbane, avens, leeks, watercress, honey, boar’s fat, lily, anise, ox-gall, hemp, rye, verdigris, fennel, thyme, wormwood, mallow, linseed, rue.  Whether the effectiveness of any of these have been clinically investigated I don’t at present know.  But the list (and it is only a fraction of the medieval analgesic pharmacopoeia) shows that just about anything would be tried.  In the seventeenth century, the index to Culpeper’s Herbal has seven separate entries for “pain” – in the reins, the bowels, the ears etc, with a total of 36 recommended specifics.[55]

Military and naval surgeons were much occupied with the results of gunpowder, not only wounds but, in the early days of unfamiliarity, burns; and burns are among the most painful lesions anyone could wish for.  Woodall recommends that topical Mel Saponis (equal quantities of honey and soap blended) or Vnguentum Tripharmacon, or Nutriton, a decoction of litharge of gold [lead monoxide] powdered in wine vinegar “taketh away all paines.”[56]

Parallel to the experiments in the 1820s by Henry Hill Hickman using CO₂ gas for general anaesthesia, came the claims of William Wright that it also had a local effect: “place a small piece of blister plaister in the finger, until as vesicle is raised, the skin of which being cut off, the oxygen of the atmosphere will occasion pain...but ease will instantly be afforded, on the finger being introduced into a jar of carbonic acid gas.”  Anyone care to try this?  Wright claimed to have used the gas during operations on the ear, a stream of gas being introduced “from a bladder furnished with a stop-cock and small tube.”[57]

In 2006 an American survey of ethnobotanicals produced 33 species currently claimed to have local analgesic/anaesthetic properties just from Puerto Rico and Colombia alone, plus another 24 claimed to be anti-inflammatories.  All these being folk medicine.[58]

One such interesting example are plants of the genus Xanthoxylum or Zanthoxylum, (most commonly Z. piperitum, Z. americanum, Z. macrophyllum, Z. simulans, Z. sancho and Z. schinifolium) which occur in subtropical areas across the globe. In Asia they are known as Szechuan peppers, and the fruits are used as a condiment; in the SE United States as “toothache trees” because of the anodyne effect when an extract from the leaves and/or bark is chewed. The effect is counter-irritant, and is described as a “tingling” or “buzzing” sensation which appears to replace the toothache pain. The plants have been under investigation for several years and just recently a paper[59] was published identifying the active agent as the alkyamide hydroxy-α-sanshool, which activates somatosensory neurons in the buccal mucosa.

So the search for alternatives to cocaine and its analogues goes on.  A number of small studies have been done to try to compare both pharmaceuticals and routes for relative efficacy from the patients’ point of view.[60] The general consensus seems to be, however, that of the drugs tested, a cocaine analogue and administration by injection still remains the most effective local anaesthetic.

References