Local Anesthesia

Drug name	UK Trade name	Concentration (%)
Maximum dose (mg/kg)
Articaine with adrenaline	Bartinest Septanest	4	7
Bupivacaine	Marcain	0.25	2.5
Lidocaine		1	3
		2
Lidocaine with adrenaline	Utilycaine Lignospan Special Xylocaine	1	7
		2
Mepivacaine	Scandonest	2	1.36 (3 mg per pound), less than 400 mg in adults
		3
Prilocaine with Felypressin	Citanest	0.5	7
		1
Prilocaine Plain	Citanest Plain	1	6

Contraindications
When considering the use of a local anaesthesia there are many factors which should be considered. In terms of contraindications associated with LA there are “absolute” and “relative” contraindications. When something is said to have an “absolute” contraindication this underlines that under no circumstance would that LA be selected to administer to that specific patient as it poses a potential life-threatening risk e.g. allergy. When the LA has a “relative” contraindication the administration of the LA is not preferable and should be avoided, but does not pose a life-threatening risk.
Type
As stated previously local anaesthesia used in dentistry can vary significantly as there are various preparations with a multitude of qualities. Each preparation has slight differences in how the anaesthetic affects the body. This is due to the use of different constituents. Local Anaesthetics which contain adrenaline such as Lidocaine (using 1:80,000 of adrenaline) or Articaine (using 1:100,000 of adrenaline) have a direct effect on the cardiac output by increasing the rate and contraction of the heart itself. Due to these effects, if a patient suffers from unstable angina or severe cardiac dysrhythmia, these preparations are often discouraged as they may predispose to unfavourable side effects.^[21] Studies found that both articaine given by infiltration and lidocaine given by inferior block were equally efficient when used for routine dental treatments in pediatric patients, however, articaine injections caused less post-operative pain. As an alternative, other preparations such as Mepivicaine Hydrochloride or Prilocaine (containing Felypressin) can be used. Prilocaine is especially suitable for a patient who wishes to avoid adrenaline or may have a latex/preservative allergy. The main contraindication of Prilocaine is that it has a short half life and it possesses a mild cytotoxic effect, therefore should be avoided in pregnancy. This cytotoxic effect can influence the uterine tone and interfere with circulation, which can pose detrimental effects on the pregnancy. Mepivicaine Hydrochloride is then considered if Prilocaine is contraindicated. Mepivicaine is the least vasodilatory anesthetic as it has no vasoconstrictors and no preservatives added.^[23]