Table 1.

Canadian maximum recommended dosages (MRD)^* of LA and sample calculation for determining maximum amount of LA that can be safely administered. Modified from Haas and Lennon¹⁰

Anaesthetic	Maximum	Sample calculation
Lidocaine (e.g. Xylocaine)	7 mg/kg up to 500 mg	Patient weighs 20 kg (44 lb), dentist administers lidocaine 2%
Articaine (e.g. Astracaine)	7 mg/kg up to 500 mg	Maximum = 7 mg/kg * 20 kg = 140 mg
Bupivacaine (e.g. Vivacaine)	2 mg/kg up to 200 mg	Lidocaine 2% = 20 mg/mL of drug
Mepivacaine (e.g. Scandonest)	6.6 mg/kg up to 400 mg	Max amount = 140 mg/ 20 mg/mL = 7 mL
Prilocaine (e.g. Citanest)	8 mg/kg up to 500 mg	Max cartridge = 7 mL/ 1.8 mL/ cartridge = 3.9 cartridges
		Therefore, the dentist can administer up to 3.9 cartridges of lidocaine 2%.

^*Values in Table 1 represent Canadian MRDs and therefore may vary significantly from country to country. It is recommended that each clinician investigate the manufacturer’s recommendations.