Mepivacaine and levonordefrin are injected locally. The dose varies and depends upon the area to be anesthetized, the vascularity of the tissues, individual tolerance and the technique of anesthesia. For infiltration and block injections in the upper or lower jaw, the average dose of 1 cartridge, containing 1.7 mL of mepivacaine HCl 2% with levonordefrin 1:20,000 will usually suffice. 5.3 cartridges (180 mg of the 2% solution) are usually adequate to effect anesthesia of the entire oral cavity.

Alpha-2-adrenergic receptors were labeled using 2.0 nM [3H]rauwolscine (80.5 Ci/mL) in 50 nM Tris buffer, pH 7.4, containing 10 mM EDTA. The final protein concentrations was approximately 500 ug/mL for the a2-assay. Phentolamine (10 uM) was used to determine the fraction of nonspecific binding. Samples were incubated at 30 °C for 30 min and then rapidly filtered (Whatman GF/C glass fiber filters presoaked in 10 uM phentolamine) and washed with 20 mL of ice-cold assay buffer on a Brandel cell harvester. Individual filters were inserted into scintillation vials, shaken, and allowed to equilibrate for 5 h with 5 mL of aqueous scintillation fluid before radioactivity counting on a Beckman LS 6800 liquid scintillation counter. The IC50 was determined by plotting the percentage specific binding at each sigmoidal Emax model. The equilibrium dissociation constant of each compound (Ki) was then calculated using the standard equation. Levonordefrin inhibits binding of radioligand with alpha-2 adrenergic receptors with Ki of 205 nM.