Articaine

Articaine [4-methyl-3-(2-propylaminopropionamido) thiophene-2-carboxylic acid methyl ester hydrochloride] has been widely used in dentistry since its approval by the U.S. FDA in the year 2000 because of its quick onset and short duration of action. The structure of articaine differs from those of all other amino amide-type local anesthetics in that it contains a thiophene ring instead of a benzene ring and a carbomethoxy group. This renders the molecule more lipophilic and, thus, easier to cross any lipoidal membranes.
Its local anesthetic potency is approximately 1.5-fold that of lidocaine, even though it has similar pKa (7.8) and plasma protein binding (76%) properties. Articaine also is metabolized primarily by plasma cholinesterases because of the presence of an ester group and, therefore, has a much shorter duration of action than lidocaine (i.e., only approximately one-fourth that of lidocaine). Articaine undergoes rapid hydrolysis of the carbomethoxy group to give articainic acid, which is eliminated either unchanged (75%) or as its glucuronides (25%). Compared with to other shortacting, amino amide-type local anesthetics, such as mepivacaine, lidocaine, or prilocaine, articaine is said to be a much safer drug for regional anesthesia and is the drug of choice for dental procedures.

Ultracain,Hoechst,W. Germany,1976

Articaine is an amide that also contains an ester linkage, which is hydrolysed rapidly so that the duration of action is short. It is available as a 4% solution with adrenaline for infiltration anaesthesia in dentistry.

Articaine is an amide based short-acting local anesthetic use for regional anaesthesia in day-case settings such arthroscopy, hand , food surgery and in dentistry.

ChEBI: 4-methyl-3-[[1-oxo-2-(propylamino)propyl]amino]-2-thiophenecarboxylic acid methyl ester is a thiophenecarboxylic acid.

3-α-Chloropropionylamino-2-carbomethoxy-4-methylthiophene (prepared from 3-amino-2-carbomethoxy-4-methylthiophene and chloropropionyl chloride) was dissolved in toluene and n-propylamine added. The whole mixture was heated to boiling for 6 to 7 hours. After cooling, the propylamine hydrochloride that had formed was removed by washing with water, The toluene phase was dried with sodium sulfate, and then the solvent and excess propylamine were removed by distillation. The oily residue was taken up in ether. The hydrochloride of 3-n-propylamino-α-propionylamino-2- carbomethoxy-4-methylthiophene was obtained by introducing hydrogen chloride gas or by means of methanolic hydrogen chloride. The base boils at 162°C to 167°C under 0.3 mm of mercury pressure and the hydrochloride melts at 177°C to 178°C.

Local anesthetic

This local amide-type anesthetic is seldom reported as allergenic even in patients sensitized to other amidetype molecules like lidocaine, prilocaine, mepivacaine, or bupivacaine.