Prilocaine () is a

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 a ...

of the amino

amide In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula , where R, R', and R″ represent organic groups or hydrogen atoms. The amide group is called a peptide bond when it i ...

type first prepared by Claes Tegner and Nils Löfgren. In its injectable form (trade name Citanest), it is often used in

dentistry Dentistry, also known as dental medicine and oral medicine, is the branch of medicine focused on the teeth, gums, and mouth. It consists of the study, diagnosis, prevention, management, and treatment of diseases, disorders, and conditions of ...

. It is also often combined with lidocaine as a topical preparation for dermal anesthesia (

lidocaine/prilocaine Lidocaine/prilocaine is a eutectic mixture of equal quantities (by weight) of lidocaine and prilocaine. A 5% emulsion preparation, containing 2.5% each of lidocaine/prilocaine, is marketed by APP Pharmaceuticals under the trade name EMLA (an a ...

EMLA Lidocaine/prilocaine is a eutectic mixture of equal quantities (by weight) of lidocaine and prilocaine. A 5% emulsion preparation, containing 2.5% each of lidocaine/prilocaine, is marketed by APP Pharmaceuticals under the trade name EMLA (an ...

), for treatment of conditions like

paresthesia Paresthesia is an abnormal sensation of the skin (tingling, pricking, chilling, burning, numbness) with no apparent physical cause. Paresthesia may be transient or chronic, and may have any of dozens of possible underlying causes. Paresthesias a ...

. As it has low cardiac toxicity, it is commonly used for intravenous regional anaesthesia (IVRA).

Contraindications

In some patients, ortho-toluidine, a metabolite of prilocaine, may cause

methemoglobinemia Methemoglobinemia, or methaemoglobinaemia, is a condition of elevated methemoglobin in the blood. Symptoms may include headache, dizziness, shortness of breath, nausea, poor muscle coordination, and blue-colored skin (cyanosis). Complications ...

, which may be treated with

methylene blue Methylthioninium chloride, commonly called methylene blue, is a salt used as a dye and as a medication. Methylene blue is a thiazine dye. As a medication, it is mainly used to treat methemoglobinemia by converting the ferric iron in hemoglobin ...

. Prilocaine may also be contraindicated in people with sickle cell anemia,

anemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, t ...

, or symptomatic hypoxia.

Combinations

It is given as a combination with the vasoconstrictor

epinephrine Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands and ...

under the trade name ''Citanest Forte''. It is used as a eutectic mixture with

lidocaine Lidocaine, also known as lignocaine and sold under the brand name Xylocaine among others, is a local anesthetic of the amino amide type. It is also used to treat ventricular tachycardia. When used for local anaesthesia or in nerve blocks, lid ...

, 50% w/w, as

. The mixture is an oil with a melting point of . A 5%

emulsion An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloids. Alth ...

preparation, containing 2.5% each of lidocaine/prilocaine, is marketed by APP Pharmaceuticals under the

trade name A trade name, trading name, or business name, is a pseudonym used by companies that do not operate under their registered company name. The term for this type of alternative name is a "fictitious" business name. Registering the fictitious name w ...

EMLA (an abbreviation for eutectic mixture of local anesthetics).

Compendial status

* United States Pharmacopeia 31

Synthesis

The amidation between o-toluidine 5-53-4(1) and 2-bromopropionyl bromide 63-76-8(2) leads to 2-bromo-N-(2-methylphenyl)propanamide 9397-79-6(3). Displacement of the remaining halide with propylamine 07-10-8(4) completed the synthesis of prilocaine (5).

References

External links