Can local lidocaine (anesthetic) and marcaine (bupivacaine) cause bradycardia after a dental procedure?

From the Guidelines

Yes, local anesthetics like lidocaine and bupivacaine (Marcaine) can potentially cause bradycardia (abnormally slow heart rate) after dental procedures, though this is relatively uncommon with standard dental doses. These medications work by blocking sodium channels in nerve cells, preventing the transmission of pain signals. However, if sufficient amounts enter the bloodstream through accidental intravascular injection or rapid absorption, they can affect the cardiovascular system, including the heart's electrical conduction system. This systemic effect can lead to decreased heart rate, hypotension, and in severe cases, cardiac arrhythmias.

Key Points to Consider

• Risk factors include using high doses, accidental intravascular injection, or patients with pre-existing heart conditions.
• Symptoms of bradycardia may include dizziness, lightheadedness, fatigue, or fainting after the procedure.
• Dentists typically minimize these risks by using appropriate doses, adding vasoconstrictors like epinephrine to slow absorption, and employing proper injection techniques including aspiration before injection to avoid blood vessels. According to the most recent study 1, minor adverse events such as bradycardia were reported in some patients who received intravenous lidocaine for postoperative pain and recovery. The study highlights the importance of careful dosing and monitoring to minimize the risk of adverse events.

Recommendations for Safe Use

• Calculate the maximum allowable safe dosage (eg, mg/kg) before administration to avoid excessive doses.
• Use lower doses in very vascular areas.
• Monitor patients closely for signs of toxicity, including bradycardia, and be prepared to provide emergency care if necessary. By following these guidelines and using local anesthetics judiciously, dentists can minimize the risk of bradycardia and other adverse events, ensuring a safe and effective procedure for their patients.

From the FDA Drug Label

Systemic absorption of local anesthetics produces effects on the cardiovascular and central nervous systems (CNS) At blood concentrations achieved with normal therapeutic doses, changes in cardiac conduction, excitability, refractoriness, contractility, and peripheral vascular resistance are minimal. However, toxic blood concentrations depress cardiac conduction and excitability, which may lead to atrioventricular block, ventricular arrhythmias, and cardiac arrest, sometimes resulting in fatalities

The use of local lidocaine and marcaine (bupivacaine) after a dental procedure can cause cardiovascular effects, including changes in cardiac conduction.

• Bradycardia is not explicitly mentioned in the label as a potential effect of these local anesthetics.
• However, atrioventricular block is mentioned, which can be associated with bradycardia.
• The label states that these effects are more likely to occur at toxic blood concentrations.
• It is essential to use incremental dosing to minimize the risk of systemic toxicity 2.

From the Research

Local Anesthetics and Bradycardia

• Local anesthetics such as lidocaine and marcaine (bupivacaine) are commonly used in dental procedures to numb the area and prevent pain.
• However, these anesthetics can have systemic effects, including effects on the cardiovascular system, as seen in studies 3, 4, 5, 6.
• Bradycardia, or a slow heart rate, is one potential cardiovascular effect of local anesthetics, as reported in cases where bupivacaine was used 3, 4, 6.

Mechanism of Action

• The exact mechanism of how local anesthetics cause bradycardia is not fully understood, but it is thought to be related to the drug's effects on the central nervous system and the heart itself 4, 5.
• Studies have shown that bupivacaine is more potent than lidocaine in producing cardiovascular effects, including bradycardia 4.
• The use of lipid emulsion has been reported as a successful treatment for reversing bupivacaine and lidocaine-induced severe junctional bradycardia 6.

Clinical Implications

• Emergency physicians and dentists should be aware of the potential for local anesthetics to cause bradycardia and other cardiovascular effects, especially in patients with preexisting cardiac conditions or those who are uremic 3, 6.
• The management of local anesthetic-induced bradycardia may involve the use of atropine, epinephrine, or other medications, as well as supportive care such as oxygen and cardiac monitoring 3, 6.
• Further research is needed to fully understand the mechanisms and clinical implications of local anesthetic-induced bradycardia, as well as the best approaches to prevention and treatment 4, 5, 7.