Pharmacology in pediatric dentistry: Local anesthetics, analgesics, and antibacterial agents
If you’ve heard me speak before, you know that I often refer to children as “aliens.” Why? Is it because they sometimes resemble extraterrestrials in early sonograms? No! Before you take any offense, please know that I love children and have the utmost respect for them. Simply put, I use the term “alien” for exactly those reasons. I want to always remind myself, my students, and the attendees of my presentations that children are not simply small adults. They have unique physical, emotional, and developmental characteristics. Their pharmacokinetic and pharmacodynamic parameters may differ greatly from those of adults. The principles of adult pharmacotherapeutics are not easily extrapolated to "fit" the profile and needs of children.1
In that sense, children may be our most vulnerable patients when it comes to potential drug interactions, adverse reactions, toxicity, and contraindications. So providing dental care to children may be particularly challenging if we are unaccustomed to doing so—and it can almost feel like we are working with patients from another planet.
Preventing pain, anxiety, and infection in children is definitely within the scope of our practice. However, imprudently using dental pharmacotherapeutic agents to that end can be potentially disastrous in children. A working knowledge of the current trends in pediatric dental pharmacology enables all dental practitioners to better treat children, more effectively consult with pediatricians, and help educate parents and caregivers. In this two-part column, we will explore the pharmacokinetic and pharmacodynamic challenges we face in treating children, with specific emphasis placed on the most frequently used medications in our practice: local anesthetics, analgesics, and antibacterial agents. We’ll start with local anesthetics.
A higher risk of toxicity in children
If you’ve been in practice for any period of time as a dental hygienist, you know that it’s common to use local anesthetics at your office. And whether you work in a state that allows dental hygienists to administer anesthesia, you know that local anesthetics are generally considered safe when properly administered. While this may sound like a contradiction of what I said earlier, some of the basic principles of local anesthetic administration do apply equally to both children and adults. However, pediatric patients have a higher risk of experiencing toxicity and serious adverse events with local anesthetics due to their decreased body weight and also to the frequent use of sedation.2
Many times, the cause of toxicity in children from local anesthetics is overdose. This is especially true with higher-concentration solutions, such as 4% articaine and prilocaine, since toxicity will be more likely with large doses. We need to use the smallest effective dose of local anesthetic solutions in children; maximum recommended doses of local anesthetics should be calculated by body weight and strictly adhered to, whenever possible.3 The ease with which a pediatric patient may be overdosed with local anesthetics is compounded by the practice of multiple quadrant dentistry and the concomitant use of sedative drugs.4
Smaller volumes provide necessary pain control
Younger patients do not need large volumes of a local anesthetic agent for pain control.4 Because of differences in anatomy, smaller volumes of local anesthetics provide the depth and duration of pain control usually necessary to successfully complete the planned dental treatment in younger patients.4 Another factor is the presence of a vasoconstrictor.2 All injectable local anesthetics have vasodilating properties. This can lead to more rapid vascular uptake, faster systemic absorption, and potentially, overdose.2,4 It is strongly recommended to include a vasoconstrictor in the local anesthetic solutions used in children, especially when multiple quadrants are anesthetized in smaller pediatric patients, unless there is a compelling reason to exclude it.4
As such, a pediatric patient in need of extensive dental work should have a treatment plan that includes multiple appointments and single quadrant dentistry, whenever possible, to avoid exceeding the recommended maximum dose of local anesthetic.2However, many younger children also require some form of pharmacological behavior management to help them endure and cooperate during long dental appointments.2
Beware of certain combinations
Both local anesthetics and sedative agents may cause additive CNS depressive effects when used together.2 Most overdose complications in children typically involve neurologic and respiratory events prior to cardiovascular events.5 The combination of local anesthetics with opioids or antihistamines may further predispose children to seizures and adverse outcomes.6 In addition, it is common practice to perform minimal conscious sedation on pediatric patients with nitrous oxide and oxygen and a benzodiazepine.2 When administered with local anesthetic, benzodiazepines increase the seizure threshold and can, therefore, mask early signs of local anesthetic overdose and directly result in cardiovascular collapse.5
We as dental practitioners must be aware of the pharmacokinetic and pharmacodynamic differences associated with pediatric patients, and not simply treat them as "small adults." Medications frequently used in dentistry may cause significant adverse events and toxicity in children. In the second installment of this column, we will explore the pharmacokinetic and pharmacodynamic challenges we face in treating pediatric dental patients with analgesics and antibacterial agents.
Editor's note: This article was updated September 2024. It originally appeared with the title "Children should be seen—and heard!" in the February 2022 print edition of RDH.
References
- Harding AM. Pharmacologic considerations in pediatric dentistry. Dent Clin North Am. 1994 Oct;38(4):733-753.
- Nicola W, Ouanounou A. Pharmacotherapy for the pediatric dental patient. Compend Contin Educ Dent. 2019 Jun;40(6):349-353.
- Moore PA. Preventing local anesthesia toxicity. J Am Dent Assoc. 1992 Oct;123(6):60-64.
- Malamed S. Handbook of Local Anesthesia. Elsevier Mosby; 2004:272.
- Sekimoto K, Tobe M, Saito S. Local anesthetic toxicity: acute and chronic management. Acute Med Surg. 2017;4(2):152-160.
- Haas DA. An update on local anesthetics in dentistry. J Can Dent Assoc. 2002;68(9):546-551.