key takeaways • The U.S. Food and Drug Administration (FDA) regularly updates maximum recommended dosages (MRDs) for local anesthetic drugs. • Although the FDA has provided MRD guidelines, patient response to drug dosage is not always predictable. • In some cases, oral health professionals are guided by lower MRD values than those approved by the FDA.2–4 • There are benefits to following lower MRDs — such as enhanced patient safety — and as long as administered doses remain within FDA recommendations, there is no breach of the guidelines. • In addition to concerns over central nervous system and cardiovascular system toxicity with increasing doses, articaine, benzocaine, prilocaine, tetracaine and lidocaine have been identified as increasing the risk of methemoglobinemia.8,9 • In addition to observing MRDs, the administration of local anesthetics continues to be guided by several factors, including the area to be anesthetized, vascularity of the tissues, technique and individual tolerances. • Restricting doses to those that provide adequate anesthesia for treatment is prudent; sound clinical judgment should guide decisions in this area. When comparing calculations of the maximum number of cartridges in the absence of a published articaine limit, there is an increased potential for over- dose. For example, 11 cartridges of 4% articaine, 1:100,000 epinephrine — considered a safe maximum dose guideline of epinephrine for healthy patients — contain almost 800 mg of articaine (11 x 72 mg per cartridge). Calculating the maximum dose for a 250-pound individual yields similar results (250 lbs x 3.2 mg/lb = 800 mg, or about 11 cartridges). Both results, in most conceivable clinical situations, may appear to conflict with FDA advice to limit doses to the smallest amount required to provide the needed anes- thesia, and exceed pre-2013 recommendations by a considerable margin (500 mg abso lute maximum versus 800 mg). In the absence of a published absolute maximum dose, many clinicians continue to observe a 500 mg absolute maximum for articaine. In addition to concerns over central nervous system (CNS) and cardio- vascular system (CVS) toxicity with increasing doses, articaine, benzocaine, prilocaine, tetracaine and lidocaine have been identified as increasing the risk of methemoglobinemia.8,9 dition’s risk rises with increasing doses.2,4,9 caine in dentistry have not resulted in methemoglobinemia,4 Whether acquired or congenital, this con- Although typical doses of arti- 800 mg exceeds typical doses by a wide margin. Restricting doses to those that provide adequate anesthesia for appropriate treatment seems prudent; as such, sound clinical judgment should guide decisions in this area. The second formulation of articaine, 4% with 1:200,000 epinephrine, deserves special mention regarding the potential for toxicity considering TheraBreath was started by a Dentist 25 years ago. Since that time, we have become the largest and fastest growing Dentist-led oral care company in America. Our formulas are free of artificial flavors and colors, contain no alcohol or astringents, and are certified Vegan, Kosher, and Gluten Free.
